Medical Terminology made Incredibly Easy Third Edition1 Key concepts of medical terminologyHealth assessment Just the facts In this chapter, you’ll learn: ♦ dissection of medical

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Medical Terminology

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IncrediblyEasy!IncrediblyEasy!

®

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The clinical treatments described and recommended in this pub-lication are based on research and consultation with nursing,medical, and legal authorities. To the best of our knowledge,these procedures reflect currently accepted practice. Neverthe-less, they can’t be considered absolute and universal recom-mendations. For individual applications, all recommendationsmust be considered in light of the patient’s clinical condition and,before administration of new or infrequently used drugs, in lightof the latest package-insert information. The authors and pub-lisher disclaim any responsibility for any adverse effects result-ing from the suggested procedures, from any undetected errors,or from the reader’s misunderstanding of the text.

© 2009 by Lippincott Williams & Wilkins. All rights reserved. Thisbook is protected by copyright. No part of it may be reproduced,stored in a retrieval system, or transmitted, in any form or by anymeans—electronic, mechanical, photocopy, recording, or other-wise—without prior written permission of the publisher, exceptfor brief quotations embodied in critical articles and reviews andtesting and evaluation materials provided by the publisher to in-structors whose schools have adopted its accompanying text-book. Printed in the United States of America. For information,write Lippincott Williams & Wilkins, 323 Norristown Road, Suite200, Ambler, PA 19002-2756.

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Library of Congress Cataloging-in-Publication DataMedical terminology made incredibly easy!. — 3rd ed.

p. ; cm.Includes bibliographical references and index.1. Medicine. — Terminology. 2. Medical sciences. — Terminology. I. Lippincott Williams & Wilkins. [DNLM: 1. Terminology as Topic. W 15 M4887 2009]R123.M394 2009610.1'4--dc22

ISBN-13: 978-0-7817-8845-8 (alk. paper)ISBN-10: 0-7817-8845-5 (alk. paper) 2008011400

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iii

ContentsContributors and consultants iv

Not another boring foreword v

1 Key concepts of medical terminology 1

2 Body structure 19

3 Skeletal system 41

4 Muscular system 69

5 Integumentary system 91

6 Cardiovascular system 117

7 Respiratory system 143

8 Gastrointestinal system 171

9 Urinary system 197

10 Reproductive system 219

11 Maternal health 243

12 Neurologic system 267

13 Endocrine system 299

14 Blood and lymphatic system 319

15 Sensory system 339

16 Pharmacology 359

17 Mental health 385

Selected references 405

Index 406

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iv

Helen Christina Ballestas, RN, MSN,

CRRN, PHD[C]

Nursing FacultyNew York Institute of TechnologyOld Westbury

Kim Davis, MSN

ICU Nurse ManagerRalph H. Johnson VA Medical CenterCharleston, S.C.

Vivian C. Gamblian, RN, MSN

Nursing FacultyBaylor UniversityLouise Herrington School of NursingDallas, Tex.

Donna Headrick, RN, MSN, FNP

Taft Community CollegeAdvanced Cosmetic DermatologyBakersfield, Calif.

Shelley Huffstutler-Hawkins, DSN,

APRN-BC, FNP, GNP, FAANP

Post Doctoral FellowUniversity of North Carolina – Chapel Hill

School of Nursing

Julia Anne Isen, RN, BS, MSN, FNP-C

FNP-C Primary CareUniversity of California, San Francisco

Hope Siddons Knight, RN, BSN

Nursing FacultyRedlands Community CollegeEl Reno, Okla.

Megan McClintock, RN, BSN

Nursing FacultyRedlands Community CollegeEl Reno, Okla.

Aaron Pack, RN, BSN

Nursing Informatics SpecialistRedlands Community CollegeEl Reno, Okla.

Noel C. Piano, RN, MS

Instructor/CoordinatorLafayette School of Practical NursingWilliamsburg, Va. Adjunct FacultyThomas Nelson Community CollegeHampton, Va.

Angela R. Roughley, RN

Registered Nurse – Critical Care UnitDeaconess HospitalOklahoma City, Okla.

Donna Scemons, RN, MSN, FNP-C,

CNS, CWOCN

Nurse PractitionerHealthcare Systems, Inc.Castaic, Calif.

Marilyn D. Sellers, APRN, BC, MSN

FNP – Behavioral Science/Mental HealthVA Medical Center Hampton, Va.

Connie K. Smith, RN, MS

Clinical Education CoordinatorMemorial Hospital of Union CountyMarysville, Ohio

Jennifer K. Sofie, APRN, MSN

Adjunct Assistant Professor & NursePractitioner

Montana State UniversityBozeman

Benita Walton-Moss, APRN, BC, DNS

Associate ProfessorJohns Hopkins University School of

NursingBaltimore, Md.

Contributors and consultants

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v

Not another boring forewordIf you’re like me, you’re too busy caring for your patients to havethe time to wade through a foreword that uses pretentious termsand umpteen dull paragraphs to get to the point. So let’s cut rightto the chase! Here’s why this book is so terrific:

It will teach you all the important things you need to knowabout medical terminology. (And it will leave out all the fluff thatwastes your time.)

It will help you remember what you’ve learned.

It will make you smile as it enhances your knowledge andskills.

Don’t believe me? Try these recurring logos on for size:

Pump up your pronunciation—charts at thebeginning of each chapter that help you “talk to thewalk” by sounding out the most difficult terms

Anatomically speaking—anatomic images that bringyou face to face with the structures you’re trying topronounce

Beyond the dictionary—sidebars on the origins ofwords, which can help you remember and dissecttheir meanings

The real world—tidbits on more informalterminology that you may hear used in daily practice.

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See? I told you! And that’s not all. Look for me and myfriends in the margins throughout this book. We’ll bethere to explain key concepts, provideimportant care reminders, and offerreassurance. Oh, and if you don’t mind,we’ll be spicing up the pages with a bit ofhumor along the way, to teach andentertain in a way that no other resourcecan.

I hope you find this book helpful. Bestof luck throughout your career!

Joy

viFOREWORD

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Dissecting medical terms

Because many medical terms derive from Greek andLatin, learning medical terminology is like learning a newlanguage. Understanding these terms can be easier if youknow how to analyze key elements and identify word as-sociations.

Take it apartMost medical terms are a combination of two or moreparts. If you can successfully interpret each part, you canusually grasp the essential meaning of the word. Thus, in-terpreting the meaning of a medical term requires knowl-edge of common medical roots, prefixes, and suffixes.

Root it outA root is the essential component of a word. Many med-ical roots signify a disease, procedure, or body part.Some roots appear at the beginning of a word, whereasothers appear after a prefix, before a suffix, or between aprefix and a suffix. In addition, two or more roots may becombined to form a word, as in cardi-o-pulmonary andcardi-o-vascular. The letter o is the most commonlyused combining vowel.

Here are some examples of roots used in differentpositions:

1

Health assessmentKey concepts of medical terminology

Just the facts

In this chapter, you’ll learn:

♦ dissection of medical terms

♦ meaning determination of medical terms usingroots, prefixes, and suffixes.

Deciphering

medical

terminology

requires

deduction, my

dear Watson.

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• a root at the beginning of a word—angioedema (angiis a root that means vessel)• a root in the middle of a word—encephalic (cephal isa root that means head)• a root at the end of a word—scleroderma (derm is aroot that means skin)• a combination of roots—phototherapy (photo is aroot that means light; therapy is a root that means treat-ment).

In the beginningA prefix consists of one or more letters attached to thebeginning of a root. Many prefixes used for medical termsare also applied to standard English vocabulary. To deter-mine the meaning of a prefix in a medical term,consider a familiar word that begins with thesame prefix. For example, the prefix anti- hasthe same meaning—against—in both antislaveryand antihistamine, literally against slavery andagainst histamine (the compound that producesallergic reactions).

At lastA suffix is one or more letters attached to the endof a root. When a suffix begins with a consonant,a combining vowel, such as o, is placed beforethe suffix. Common use of suffixes in medical ter-minology includes adding a -y to a word to de-note a procedure, such as gastroscopy, whichmeans endoscopic examination of the stomach.Similarly, adding -ly to a word denotes an act orprocess; for example, splenomegaly, whichmeans the abnormal enlargement of the spleen.

Break it down; build it upWith a bit of practice, you’ll quickly discover howeasy it can be to interpret the parts of a medicalterm and then combine them to identify theterm’s meaning. For example, in acrocyanosis,the root acr (extremities) and the vowel o arecombined with the root cyan (blue) and the suf-fix -osis (condition) to form a term that means acondition characterized by blue extremities.(For another example of how to dissect a medicalterm to decipher its meaning, see ’Dem bones.)

2KEY CONCEPTS OF MEDICAL TERMINOLOGY

If you can

understand the

building blocks, then

you’ll have the

foundation for

learning even the

most complicated

medical terminology.

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Forming plural words

Plural words in English are usually formed by adding s ores to the end of a noun. The rules for forming plurals ofmany medical terms are different because of their Greekand Latin roots. Generally, plural words derived fromthese two languages are formed by adding or substitutingvowels or syllables at the end of the word.

Examples of plurals of medical terms are:• maculae (singular: macula)• adenomata (singular: adenoma)• glomeruli (singular: glomerulus)• pelves (singular: pelvis).

Pronouncing medical terms

Medical terms can be difficult to pronounce if you’ve nev-er heard them spoken. In this book, we’ll show you howto pronounce words by placing them in all capital letters,with the syllable receiving the greatest stress appearingin tall capitals and the remaining syllables in smaller capi-tals. For example, in the word cancer, the stress is on thefirst syllable, so it would appear as follows: CAN-CER.

Here are some additional tips for pronunciation:

3PRONOUNCING MEDICAL TERMS

A specialist in osteopathology studies bone diseases. The rootoste is the Greek word for bone. A second root, patho, is derivedfrom pathos, meaning disease. The suffix -logy is derived from theGreek root logia, meaning the study of. Put these parts togetherand you have the definition for osteopathology—the study of bonediseases.

At the root of disease?

A branch of medicine called osteopathy contends that skeletalmisalignment impinges on adjacent nerves and blood vessels,causing disease.

Beyond the dictionary

’Dem bones

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• only the s sound in ps is pronounced, as inPseudomonas• only the n sound in pn is pronounced, as in pneumo-coccal• g and c assume the soft sounds of j and s, respectively,when used before e, i, and y; examples are gene, gin-givitis, cycle, and cytology• ph sounds like f, as in phlegm• x sounds like z, as in xeroderma (pronounced ZEE-ROH-DER-MAH)• g and c have hard sounds in front of other letters, suchas gangrene, gastritis, cornea, and cortex• ae and oe are pronounced ee, as in fasciae• i at the end of a word usually denotes a plural and ispronounced eye, as in fasciculi• es at the end of a word may be pronounced as a sepa-rate syllable, as in nares, pronounced NEH-REEZ.

Because phonetic spelling isn’t used in medicine, it’simportant to consult a dictionary when in doubt aboutpronunciation. Also, some terms sound the same but arespelled differently and refer to different things. For exam-ple, ileum and ilium are pronounced alike, but the firstterm is part of the intestinal tract and the second one is apelvic bone.

Understanding eponyms

An eponym is a medical term that’s derived from thename of a person, usually the scientist who discoveredthe corresponding body part or disease. Many proceduresand tests are also named after the persons who inventedor perfected them.

Name that conditionExamples of eponyms for medical conditions include:• Addison’s disease, a syndrome resulting from insuffi-cient production of hormones from the cortex of theadrenal gland• Alzheimer’s disease, a type of irreversible dementia• Cushing’s syndrome, a syndrome resulting from theproduction of excess cortisol from the adrenal cortex


Be careful!

Words like ileumand ilium sound

the same but

have different

meanings.

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• Parkinson’s disease, a progressive degeneration ofthe nervous system that causes weakness, rigidity, andtremors• Stokes-Adams syndrome, a heart condition charac-terized by sudden loss of consciousness.

Famous body partsParts of the body named for their discoverers include:• Bartholin’s glands, located in the female perineum• Cowper’s glands, located beneath a portion of themale urethra• Wernicke’s center, a speech center in the brain.

Featured proceduresExamples of eponyms for medical procedures include:• Allen’s test, a test for occlusion of radial or ulnar arteries• Belsey Mark IV operation, a procedure to correctgastroesophageal reflux• Heimlich maneuver, a technique for removing foreignobjects from the airway of a choking victim.

What’s in a name?Medical devices such as catheters (tubes passed throughbody channels) are often named for their inventors; forexample:• the Foley catheter is an indwelling urinary catheter• a Hickman catheter is a central venous catheter in-serted for long-term use• a Malecot catheter is a tube used for gastrostomyfeedings• a Swan-Ganz catheter is threaded into the pulmonaryartery.

Recognizing word components

Words can be made up of roots, prefixes, and suffixes. (SeeCommon prefixes, roots, and suffixes, pages 6 to 13.)

At the root of it allA root is just what the word implies—where it all starts.A root can be a whole word or part of a word. Roots comefrom many different languages (such as Greek, Latin,

5RECOGNIZING WORD COMPONENTS

(Text continues on page 14.)

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Common prefixes, roots, and suffixes

Knowing these common prefixes, roots, and suffixes will help you decipher unfamiliar medical terms.

Word component

Prefixes

a(n)-

ab-

ad-

ambi-

ante-

anti-

apo-

aut(o)-

bi-

diplo-

dys-

ec-

end(o)-

eu-

ex-

hetero-

hyper-

hypo-

infra-

intra-

juxta-

macr(o)-

mal-

mega-

Meanings

absence, without

away from

toward

both sides

before, forward

against

away from

self

two

double

difficult, painful

out of

inward

normal, health

outside

other, different

above, beyond

below

beneath

within, into

near

large, long

bad, abnormal

great, large

Examples

anuria (lack of urine output)

abduct (move away from)

adduct (move toward)

ambidextrous (using both hands)

anterior (front of the body)

antibody (immune response to an organism)

apophysis (growth or protuberance)

autoanalysis (self-analysis)

bigeminy (occurring in pairs)

diplopia (double vision)

dysuria (painful urination)

ectopic (out of place)

endoscope (a device used to examine a body cavity)

euthyroid (normal thyroid function)

exfoliation (peeling of layers)

heterogeneous (different characteristics)

hypernatremia (excess sodium)

hypotension (low blood pressure)

infra-axillary (below the axilla)

intramuscular (into the muscle)

juxta-articular (near a joint)

macromastia (excessive breast size)

malformation (abnormally formed)

megacolon (enlarged colon)

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Common prefixes, roots, and suffixes (continued)

Word component

Prefixes (continued)

meta-

micr(o)-

mono-

morph(o)-

multi-

olig(o)-

par(a)-

peri-

pico-

poly-

post-

pre-

pro-

pseudo-

re-

retr(o)-

semi-

sub-

super-

supra-

tetra-

trans-

Meanings

beyond, change

small

one

shape

many

few, little

near, beside, accessory to

around

one-trillionth

much, many

behind, after

before, in front

favoring, supporting, substituting for, infront of

false

back, contrary

backward

half

under

above

above, upon

four

across, through

Examples

metaphase (second stage of cell division)

microbe (tiny organism)

monochromatic (having only one color)

morphology (study of the form and structure oforganisms)

multifocal (arising from many locations)

oliguria (too little urine)

paracentesis (puncture of a cavity for aspirationof fluid)

pericecal (around the cecum)

picornavirus (extremely small RNA virus)

polydipsia (excessive thirst)

postoperative (after surgery)

preanesthesia (before anesthetic is given)

procoagulant (promotes coagulation)

pseudocyst (a cavity resembling a true cyst)

recurrent fever (fever that returns after a remission)

retroauricular (behind the auricle)

semiflexion (position of a limb midway betweenextension and flexion)

subclinical (without symptoms)

supercilia (the eyebrow)

supraorbital (above the orbit)

tetralogy (group of four)

transdermal (entering through the skin)

(continued)

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Word component

Roots

abdomin(o)-

acou-

acr(o)-

aden(o)-

adipo-

alb-

andr(o)-

angi(o)-

ankyl-

bili-

blast- or -blast

blephar(o)-

brachi(o)-

brady-

calc-

carcin(o)-

cardi(o)-

caud-

cephal(o)-

cerebr(o)-

cervic(i)(o)-

chol(e)-

chondr(o)-

col(i)(o)-

Meanings

abdomen

hearing

extremity, peak

gland

fat

white

male

vessel

crooked, fusion

bile

embryonic state

eyelid

arm

slow

heel

cancer

heart

tail

head

cerebrum

neck

bile

cartilage

colon

Examples

abdominopelvic (abdomen and pelvis)

acoustics (the science of sounds)

acrodermatitis (inflammation of skin of the extremities)

adenocele (cystic tumor in a gland)

adipose (fatty)

albumin (protein found in the blood)

androgen (male sex hormone)

angiography (X-ray of a vessel)

ankylosis (consolidation of a joint)

biliary (pertaining to bile or the gallbladder)

blastocyte (embryonic cell)

blepharitis (inflammation of the eyelid)

brachial artery (artery of the upper arm)

bradycardia (slow heart rhythm)

calcaneus (heel bone)

carcinoma (malignant growth)

cardiac muscle (heart muscle)

caudal (toward the tail)

cephalalgia (pain in the head)

cerebral embolism (occlusion of a cerebral vessel by ablood clot)

cervical plexus (network of cervical nerves)

cholecystitis (inflammation of the gallbladder)

chondritis (inflammation of cartilage)

colitis (inflammation of the colon)

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Word component

Roots (continued)

cost(o)-

cut-

cyan(o)-

cyst(i)(o)-

cyt(o)-

derm- or -derm

dors(i)(o)-

enter(o)-

erythr(o)-

fasci-

febri-

fil-

galact(o)-

gastro-

ger(o)- or geront(o)-

gest-

gloss(o)-

glyc(o)- or gluc(o)-

gyn(o)-

heme(a)(o)- or hemato-

hepat(o)-

hist(i)(o)-

hydro-

hyster-

Meanings

rib

skin

blue

bladder

cell

skin

back

intestine

red

bundle

fever

threadlike

milk

stomach

aging

carry

tongue

sweet

woman, particularly female reproductiveorgans

blood

liver

tissue

water, hydrogen

uterus

Examples

costochondral (relating to a rib and its cartilage)

cutaneous (relating to skin)

cyanotic (blue colored)

cystitis (inflammation of the urinary bladder)

cytology (study of cells)

dermatitis (skin inflammation)

dorsiflexion (upward bending of hand or foot)

enterocolitis (inflammation of the intestines and colon)

erythrocytes (red blood cells)

fasciae (bundles of muscle fibers)

febrile (feverish)

filament (fine thread)

galactose (sugar obtained from milk)

gastritis (inflammation of the stomach)

gerontology (study of aging)

gestation (pregnancy)

glossitis (inflammation of the tongue)

glycogen, glucogen (forms of sugar)

gynecology (study of women’s reproductive organs)

hematology (study of blood)

hepatitis (inflammation of the liver)

histography (process of describing tissue and cells)

hydrops (excess watery fluid)

hysterectomy (surgical removal of the uterus)

(continued)

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Word component

Roots (continued)

ile(o)-

ili(o)-

ischi(o)-

jejun(o)-

kerat(o)-

kine(t)(o)-

labio-

lact(o)-

laryng(o)-

latero-

leuk(o)-

lip(o)-

lith(o)-

mamm(o)-

mast(o)-

melan(o)-

meno-

ment-

mio-

mito-

my(o)-

myc(o)-

myel(o)-

myx-

Meanings

ileum

ilium, flank

hip

jejunum

horny tissue, cornea

movement

lips

milk

larynx

side

white

fat

stone

breast

breast

black

menses

mind

less, smaller

threadlike

muscle

fungus

marrow, spinal cord

mucus

Examples

ileostomy (surgical opening in the ileum)

iliac muscle (muscle that allows thigh movement)

ischiopubic (pertaining to the ischium and pubes)

jejunectomy (excision of the jejunum)

keratectasia (a thin, scarred cornea)

kinetic (pertaining to motion)

labiograph (an instrument that records lip movement)

lactation (secretion of milk by the breasts)

laryngectomy (surgical removal of the larynx)

lateroflexion (flexion to one side)

leukocytes (white blood cells)

lipedema (excess fat and fluid in subcutaneous tissue)

lithocystotomy (surgical removal of bladder stones)

mammogram (breast X-ray)

mastectomy (surgical removal of breast tissue)

melancholia (depression)

menostaxis (prolonged menstrual period)

mental illness (psychiatric disorder)

miosis (excessive contraction of the pupil)

mitochondria (rod-shaped cellular organelle)

myocele (hernia of muscle)

mycology (study of fungi and fungal diseases)

myelalgia (pain in the spinal cord)

myxoid (resembling mucus)

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Word component

Roots (continued)

nas(o)-

nephr(o)-

ocul(o)-

ophthalm(o)-

orchi(o)-

oro-

oss- or oste(o)-

ot(o)-

ox(y)-

path(o)-

ped(o)-

pharmaco-

pharyng(o)-

phleb(o)-

phot(o)-

plasm(o)-

pleur(o)-

pneum(o)-

pod(o)-

proct(o)-

prote(o)-

psych(o)-

pulmo(n)-

pyel(o)-

Meanings

nose

kidney

eye

eye

testes

mouth

bone

ear

oxygenation

disease

child

medicine

pharynx

vein

light

liquid part of blood

pleura, rib, side

lung

foot

rectum

protein

mind

lung

kidney

Examples

nasolabial (between the nose and lip)

nephritis (kidney inflammation)

oculomotor (eye movement)

ophthalmia (inflammation of the eye)

orchitis (inflammation of the testes)

oronasal (mouth and nose)

osteomyelitis (inflammation of bone and muscle)

otitis (ear inflammation)

oxyhemoglobin (hemoglobin combined with molecularoxygen)

pathogen (disease-causing organism)

pediatrics (care of children)

pharmacotherapy (treatment with medication)

pharyngitis (sore throat)

phlebitis (inflammation of a vein)

phototherapy (treatment by exposure to light)

plasminogen (protein found in tissues and body fluids)

pleurisy (inflammation of the pleura)

pneumonia (inflammation of the lung)

podiatry (care of the foot)

proctectomy (excision of the rectum)

proteinemia (excess protein in the blood)

psychiatry (study and treatment of mental disorders)

pulmoaortic (pertaining to the lungs and aorta)

pyelonephrosis (disease of the kidney and renal pelvis)

(continued)

845501.qxd 8/19/08 4:01 PM Page 11



Word component

Roots (continued)

pyr(o)-

ren(o)-

rhin(o)-

rub(r)-

sangui-

sarc(o)-

scler(o)-

scolio-

sensi-

sep-

soma- or somat(o)-

sten(o)-

tachy-

therm(o)-

thorac(o)-

thromb(o)-

toxi(o)-

trache(o)-

ur(o)-

vas(o)-

ven(i)(o)-

vesic(o)-

Meanings

heat

kidney

nose

red

blood

flesh

hard

crooked

perception, feeling

decay

body

narrow

rapid, swift

heat

chest

clot

poison

trachea

urinary, urine

vessel

vein

bladder

Examples

pyrogen (an agent that causes fever)

renography (X-ray of the kidney)

rhinitis (inflamed mucous membranes of the nose)

bilirubin (bile pigment)

sanguineous drainage (bloody drainage)

sarcoma (a highly malignant tumor made of connectivetissue cells)

sclerosis (hardening of tissue)

scoliosis (curvature of the spine)

sensory (pertaining to the senses)

sepsis (infection in the bloodstream)

somatization (psychiatric condition expressed throughphysical symptoms)

stenosis (narrowing of a body passage)

tachycardia (rapid heart beat)

thermometer (instrument for measuring temperature)

thoracotomy (surgical opening of the chest wall)

thrombectomy (excision of a clot from a blood vessel)

toxicosis (poisoning)

tracheobronchitis (inflammation of the trachea andbronchi)

uropoiesis (formation of urine)

vasospasm (spasm of a blood vessel)

venosclerosis (sclerosis or hardening of the veins)

vesicospinal (pertaining to the urinary bladder andspine)

845501.qxd 8/19/08 4:01 PM Page 12



Word component

Suffixes

-algia

-ectomy

-itis

-lys(i)(o)

-oma

-osis

-phob

-plasia

-plasty

-plegia

-pnea

-poiesis

-praxia

-rrhea

-scope

-stomy

-taxis

-tomy

-tripsy

-trophy

Meanings

pain

surgical removal

inflammation

breakdown

tumor

condition

abnormal fear

growth

surgical repair

paralysis

breathing

production

movement

fluid discharge

observe

opening

movement

incision

crushing

growth

Examples

neuralgia (nerve pain)

splenectomy (removal of the spleen)

colitis (inflammation of the colon)

fibrinolysis (breakdown of a clot)

blastoma (cancer composed of embryonic cells)

fibrosis (formation of fibrous tissue)

agoraphobia (fear of open spaces)

hypoplasia (incomplete development)

angioplasty (surgical repair of blood vessels)

paraplegia (paralysis of lower body)

apnea (absence of breathing)

hematopoiesis (production of blood cells)

apraxia (inability to perform purposeful movement)

diarrhea (frequent soft or liquid bowel movements)

endoscope (tool for observing the interior of bodyorgans)

colostomy (portion of the colon is opened and broughtthrough the abdominal wall)

ataxia (uncoordinated movements)

thoracotomy (surgical opening of the chest wall)

lithotripsy (crushing stones in the bladder, kidney,gallbladder, or other organs)

hypertrophy (overgrowth)

845501.qxd 8/19/08 4:01 PM Page 13

Arabic, French, and German) and find their way into Eng-lish.

Perfect prefixA prefix is a word component or whole word that attach-es to the front of a root. A prefix can drastically changethe meaning of a word. For example, the prefix extra-changes the word ordinary into extraordinary.

Super suffixA suffix is a word component that attaches to the end ofa root. Among other feats, a suffix can change the form of a word from an adjective, for instance, into an adverb. So you could add the suffix -ly to extreme to make ex-tremely (as in extremely interesting).


Memoryjogger

To rememberwhere a pre-

fix goes and where asuffix goes, you cando two things:

Think of the wordprefix: Pre- means be-fore, so a prefix is aword or word compo-nent that’s “fixed” tothe word “before” theroot. If the prefixcomes before theroot, then the suffixcomes afterwards.

If that doesn’tjazz you, just use thealphabet: P comesbefore S in the alpha-bet, so a prefixcomes before a suf-fix—and before aroot, for that matter,which starts with R.so now you have PRS(pretty rivetingstuff?).

Prefixes and

suffixes are

important, but focus

on the root of the

word to get the

meaning quickly.

845501.qxd 8/19/08 4:01 PM Page 14

15VOCABULARY BUILDERS

Vocabulary builders

Across

1. Suffix meaning production4. Root for cancer9. Root for decay10. Root for fat11. Suffix in splenectomy meansthis (two words)13. An eponymic maneuver

15. An eponymic speech center inthe brain (two words)18. Root for male19. Root for eye21. Root for water22. Root for bone

Down

1. Syllable attached to the begin-ning of a word2. Suffix for inflammation

3. Pro- means this (two words)5. Phobia is a root meaning this(two words)6. Second root in erythrocyte

means this

7. Root of pediatric

8. Meaning of root in 7 down12. Root for heart14 .Prefix meaning upon16. Prefix meaning different17.Term for a word derived from aperson’s name20. Root for vessel

At a crossroadsCompleting this crossword puzzle will help you get to the rootof medical vocabulary. Good luck!

Answers are on page 18.

1 2 3 4 5 6

7

8

9 10

11

12 13

14

15

16 17

18

19 20

21

22

845501.qxd 8/19/08 4:02 PM Page 15


Match gameMatch the following roots and prefixes to their correct meanings.

Clues

1. Super

2. Tachy

3. Thrombo

4. Thermo

5. Poly

6. Post

7. Oxy

8. Mono

9. Lith

10. Mega

Choices

A. Rapid

B. Stone

C. Above

D. Large

E. Heat

F. After

G. Clot

H. Oxygen

I. Many

J. One

Finish lineFill in the blanks below with the words that correctly identify key concepts of medicalterminology.

Generally, plural words derived from Latin and Greek are formed by adding orsubstituting ________ or syllables at the end of the word.

A ________ consists of one or more letters attached to the beginning of a root.

In the word oliguria, the prefix olig means ___________.

A ________ is the essential component of a word.

The term Alzheimer’s disease is an example of an ____________.

A _________ is one or more letters attached to the end of a root.

The plural of pelvis is ___________.


2

1

3

4

5

6

7

845501.qxd 8/19/08 4:02 PM Page 16


Talking in circlesUse the clues below to fill in the blanks with the appropriate word. Then unscramble thecircled letters to find the answer to the question posed below.

1. ____ ____ ____ ____ ____ ____

2. ____ ____ ____ ____ ____ ____

3. ____ ____ ____ ____ ____

4. ____ ____ ____ ____

5. ____ ____ ____ ____ ____

6. ____ ____ ____ ____ ____ ____ ____ ____

1. This root means mental health.2. This root means growth.3. This prefix means backward.4. This prefix means against.5. Stone is the meaning of this root.6. If your patient has a sore throat, you may have to use this root and the suf-fix -itis to describe the condition.

You look like you

bumped your nose.

Do you know what

I think you need?


845501.qxd 8/19/08 4:02 PM Page 17


1. C; 2. A; 3. G; 4. E; 5. I; 6. F; 7. H; 8. J; 9. B; 10. D

Match game

1. Vowels; 2. Prefix; 3. Little; 4. Root; 5. Eponym; 6. Suffix; 7. Pelves.

Finish line

1. Psycho; 2. Trophy; 3. Retro; 4. Anti; 5. Litho; 6. PharyngoAnswer to puzzle—Rhinoplasty

Talking in circles

At a crossroads

Answers

1P O

2I E S I

3S

4C

5A R

6C I N O

R T U7P B E

E I B E N L8C

F9S E P S

10A D I P O L H

I T R I

X11S U R G I C A L R E M O V A L

T A D12C U

13H E I M L I C H

14S A T F

U15W E R N I C K E S C E N T E R

P D N A

R I G16H R

17E

18A N D R O F E P

19O P H T H

20A L M O

R E N N

R G21H Y D R O

22O S T E O I M

845501.qxd 8/19/08 4:02 PM Page 18

Cells: Nature’s building blocks

The cell is the body’s basic building block and the small-est living component of an organism. In the late 1600s,British physicist Robert Hooke first observed plant cellswith a crude microscope. He decided that the structuresreminded him of tiny prison cells—hence the name cell.(See Pronouncing key terms related to the cell, page 20.)

Specialized unitsThe human body contains millions of cells groupedinto highly specialized units that function together.Large groups of individual cells form tissues, such asmuscle, blood, and bone. Tissues in turn form organs,such as the brain, heart, and liver. Organs and tissuesare integrated into body systems—such as the centralnervous system, cardiovascular system, and digestivesystem.

A peek inside the cellCells are composed of many structures, or organelles,that each have a specific function. The word organellesis from the neo-Latin word organella, an altered form of

2

Health assessmentBody structure

Just the facts


♦ terminology related to cells, organs, and tissues

♦ terminology related to the systems of the body

♦ terminology related to the directions, regions, andpositions of the body.

Cells like

me are the

basic building

blocks of the

body.

845502.qxd 8/19/08 4:24 PM Page 19

organum, which means organ. (See Just your averagecell.)

Cyto surroundingsOrganelles live in cytoplasm—an aqueous mass that’ssurrounded by the cell membrane. Cyto- is from theGreek root kytos, which means container or body; it de-notes a relationship to a cell. The cell membrane, alsocalled the plasma membrane, encloses the cytoplasmand forms the outer boundary of each cell.

Nuclear powerThe largest organelle is the nucleus, a word derived fromthe Latin word nuculeus, which means kernel. The nu-cleus is the control center of the cell. It stores deoxyribo-nucleic acid (DNA), which carries genetic material and isresponsible for cellular reproduction or division.

The typical animal cell is characterized by several ad-ditional elements:

20BODY STRUCTURE

Below is a list of key terms, along with the correct way to pro-nounce them.

Pump up your pronunciation

Pronouncing key terms related tothe cell

Adenosine

Cytokinesis

Epithelial

Golgi (as in Golgi apparatus)

Meiosis

Mitochondria

Ribonucleic acid

Squamous

UH-DEEN-OH-SEEN

SEYE-TOE-KUH-NEE-SIS

EH-PEH-THEE-LEE-UL

GAWL-JEE

MEYE-OH-SIS

MEYE-TOE-KAHN-DREE-UH

REYE-BOH-NOO-KLAY-IK AS-iD

SKWAY-MUHS

845502.qxd 8/19/08 4:24 PM Page 20

• Adenosine triphosphate, the energy that fuels cellu-lar activity, is made in the mitochondria, the cell’s pow-er plant.• Ribosomes and the endoplasmic reticulum synthe-size proteins and metabolize fat within the cell.• The Golgi apparatus holds enzyme systems that assistin completing the cell’s metabolic functions.• Lysosomes contain enzymes that allow cytoplasmic di-gestion. (See Why call it a lysosome? page 22.)

21CELLS: NATURE’S BUILDING BLOCKS

The illustration below shows the components and structures of a cell. Each part has a function in maintaining the cell’s life andhomeostasis.

Anatomically speaking

Just your average cell

Microvilli

Mitochondrion

Ribosomes

Endoplasmic reticulum(EHN-DOH-PLAHZ-MIKREH-TIK-YOU-LUHM)

Cytoskeleton

Golgi apparatus

Cell membrane

Centrioles

Lysosome(LEYE-SOH-SOHM)

Nucleus

Nucleolus(NEW-KLEE-OH-LUHS)

845502.qxd 8/19/08 4:24 PM Page 21

Cell division and reproductionIndividual cells are subject to wear and tear and must re-produce quickly to replace themselves. Genetic informa-tion passes from one generation of cells to the next in anintricate process that is vital to survival. Mistakes herecan lead to lethal genetic disorders, cancer, and otherconditions.

MitosisAll cells except gametes (ova and spermatozoa) repro-duce through a process called mitosis (from the Greekroot mitos, which means thread, with the suffix -osis,which denotes an action or state). During mitosis, thenucleus and genetic material of the cell divide, resultingin the formation of two separate daughter cells. Theprocess is completed when the cell body completes its di-vision (called cytokinesis, from the Greek root kytosand the Greek word kinesis, which means movement).(See Divide and conquer: Five stages of mitosis.)

Ready? Set? DivideCell division consists of one inactive phase and four activephases. Before a cell can divide, it must double in massand content. This begins during the inactive growth phaseof mitosis, called interphase. At this phase, chromatin(the network of small, slender rods in the nucleus thatgive it its glandular appearance) begins to form.

Replication and duplication of DNA occur during thefour active phases of mitosis:

prophase

metaphase

anaphase

telophase.

ProphaseDuring prophase, the chromosomes coil and shorten andthe nuclear membrane dissolves. Each chromosome ismade up of a pair of strands, called chromatids. Chro-matids are connected by a spindle of fibers called a cen-tromere.

22BODY STRUCTURE

Why call it alysosome?

The term lysosome

comes from the Greekword lysis, which meansdissolution. In plainterms, lysis means de-struction by enzymaticdigestion.

Beyond thedictionary

Memoryjogger

As a way toremember

the processes of mi-tosis, think of thephrase “I pulled myact together”:

Interphase

Prophase

Metaphase

Anaphase

Telophase.

845502.qxd 8/19/08 4:24 PM Page 22

MetaphaseDuring metaphase, chromosomes line up in the centerof the cell. The centromeres then replicate.

23CELLS: NATURE’S BUILDING BLOCKS

Divide and conquer: Five stages of mitosis

Through the process of mitosis, the nuclear content of all body cells (except gametes) reproduces and divides. The result is theformation of two new daughter cells.

Interphase

During interphase, the nucleus and nuclear membrane arewell defined, and the nucleolus is visible. As chromosomesreplicate, each forms a double strand that remains attachedat the center by a centromere.

Prophase

In prophase, the nucleolus disappears and the chromosomesbecome distinct. Chromatids, halves of each duplicated chro-mosome, remain attached by the centromere. Centriolesmove to opposite sides of the cell and radiate spindle fibers.

Metaphase

Metaphase occurs when chromosomes line up randomly inthe center of the cell between the spindles, along the meta-phase plate. The centromere of each chromosome then repli-cates.

Anaphase

Anaphase is characterized by centromeres moving apart,pulling the separate chromatids (now called chromosomes) toopposite ends of the cell. The number of chromosomes ateach end of the cell equals the original number.

Telophase

During telophase, the final stage of mitosis, a nuclear mem-brane forms around each end of the cell and spindle fibersdisappear. The cytoplasm compresses and divides the cell inhalf. Each new cell contains the diploid (46) number of chro-mosomes.

Centrioles

Nucleolus

Centrioles

Spindle fibers

Centromere

Metaphaseplate

Chromosomes

Nuclearmembrane

845502.qxd 8/19/08 4:24 PM Page 23

AnaphaseAt the onset of anaphase, centromeres begin to separateand pull the newly replicated chromosomes toward oppo-site sides of the cell. The centromere of each chromo-some splits to form two new chromosomes, each consist-ing of a single DNA molecule. By the end of anaphase, 46chromosomes are present on each side of the cell.

TelophaseIn the final step of mitosis—telophase—a new mem-brane forms around each set of 46 chromosomes. Thespindle fibers disappear and the cytoplasm divides, pro-ducing two new identical “daughter” cells. Each of thesecells can grow and develop, perhaps becoming a motherto new cells. (See Tell me about telophase.)

MeiosisGametes (ova and spermatozoa) reproduce through aprocess called meiosis (Greek, meaning lessening). Theword gamete comes from the Greek root gamet, whichmeans either wife (gamete) or husband (gametes) de-pending on its ending. Ova is the plural form of ovum,which means egg; both words come directly from Latinwithout change. Spermatozoa is the plural form of sper-matozoon, formed from the Greek spermat, meaningseed, and the Greek root zôion, meaning animal.

In meiosis, genetic material between similarly struc-tured chromosomes is intermixed and the number ofchromosomes in the four daughter cells diminishes byhalf. Meiosis consists of two divisions separated by aresting phase.

Fluid movementA cell must shuttle various molecules in and out throughthe plasma membrane and between compartments insidethe cell. There are several different ways fluids andsolutes (dissolved substances) move through mem-branes at the cellular level.

Going with the flowIn diffusion, solutes move from an area of higher con-centration to an area of lower concentration. This move-ment eventually results in an equal distribution of solutes

24BODY STRUCTURE

Tell me abouttelophase

The prefix telo- intelophase is derivedfrom the Greek word te-

los, which means an ul-timate end. Telophasemarks the end of mitosis,yielding two daughtercells.


845502.qxd 8/19/08 4:24 PM Page 24

within the two areas. Diffusion is known as passivetransport because no energy is needed to make it hap-pen. Like fish traveling downstream, solutes involved indiffusion just go with the flow.

Letting fluids throughOsmosis (from the Greek root osm, meaning to push,and the Greek suffix -sis, which is used to form a nounfrom a word that was originally a verb) is another passivetransport method. Unlike diffusion, osmosis involves themovement of a water (solvent) molecule across the cellmembrane from a dilute solution, one with a high con-centration of water molecules, to a concentrated one,one with a lower concentration of water.

Osmosis is influenced by the osmotic pressure of asolution. Osmotic pressure reflects the water-attractingproperty of a solute. It’s determined by the number of dis-solved particles in a given volume of solution.

Energy required Unlike passive transport, active transport requires en-ergy. Usually, this mechanism moves a substance from anarea of lower concentration to an area of higher concen-tration. Think of this as swimming upstream. When a fishswims upstream, it uses energy.

Against the grainThe energy required for a solute to move against a con-centration gradient comes from a substance producedand stored within the cell, adenosine triphosphate, orATP. ATP supplies the energy for solute movement in andout of cells. Some solutes, such as sodium and potassi-um, use ATP to move in and out of cells in a form of ac-tive transport called the sodium-potassium pump. Oth-er solutes that require active transport to cross cell mem-branes include calcium ions, hydrogen ions, amino acids,and certain sugars.

Body tissues: Holding it all together

Tissues are groups of similar cells that perform the samerole; each tissue has at least one unique function. Tissuesare classified by structure and function and are dividedinto four types: epithelial, connective, muscle, and nervous.

25BODY TISSUES: HOLDING IT ALL TOGETHER

Sometimes you

need to work at it.

Active transport

requires energy,

like swimming

upstream.

845502.qxd 8/19/08 4:24 PM Page 25

Epithelial tissueEpithelial tissue (the epithelium) is a continuous cel-lular sheet that covers the body’s surface, lines body cavi-ties, and forms certain glands. It contains at least twotypes of epithelial cells.

Endothelium and mesotheliumEpithelial tissue with a single layer of squamous cells at-tached to a basement membrane is called endothelium.Such tissue lines the heart, lymphatic vessels, and bloodvessels. Tissue that lines the surface of serous mem-branes, such as the pleura, pericardium, and peritoneum,is called mesothelium. Epithelial tissue is classified bythe number of cell layers it has and the shape of the cellson its surface.

Layer upon layerDepending on the number of cell layers, epithelial tissuemay be simple or stratified:• Simple epithelial tissue contains one layer of cells.• Stratified epithelial tissue has three or more layers.

Classified by shapeBased on the shape of its surface cells, epithelial tissuemay be characterized as squamous, columnar, cuboidal,transitional, or pseudostratified columnar:• Squamous epithelial tissue has flat surface cells.• Columnar epithelial tissue has tall, cylindrical, prism-shaped surface cells.• Cuboidal epithelial tissue has cube-shaped surface cells.• Transitional epithelial tissue has a unique arrange-ment of cell shapes in a stratified (layered) sheet. Thistype of tissue can stretch, such as the bladder doeswhen it’s full.• Pseudostratified columnar epithelial tissue hasone layer of oddly shaped columnar cells.

Connective tissueConnective tissue is classified by structure into oneof the following four categories: fibrous, bone, cartilage,or blood. Connective tissue is found in or around almostevery organ of the body. Its function is to support, con-nect, and transport.

26BODY STRUCTURE

I swear it’s true.

The prefix pseudo-

means false.

845502.qxd 8/19/08 4:24 PM Page 26

FibrousFibrous tissue can be dense, loose, or adipose.

Cut looseLoose connective tissue has large spaces that separatethe fibers and cells. It contains much intercellular fluid.

Dense supportDense connective tissue provides structural support. Ithas a greater fiber concentration.

Who are you calling fat?Adipose tissue (fat) is a specialized type of loose con-nective tissue in which a single fat droplet occupies mostof the cell. It cushions internal organs and acts as a re-serve supply of energy. (See Where adipose comes from.)

BoneBone is hard, dense tissue with a calcified matrix.

CartilageCartilage is a flexible matrix with a gristlelike gel.

BloodBlood is a liquid matrix that contains red and whiteblood cells.

Muscle tissue The three basic types of muscle tissue are striated, car-diac, and smooth.

Striated muscle tissueStriated muscle tissue gets its name from the striped, orstriated, appearance it has when viewed under a micro-scope. All striated muscle tissue capable of voluntarycontraction is called skeletal muscle tissue.

Cardiac and smooth muscle tissueCardiac muscle tissue is striated but it contracts invol-untarily. Smooth muscle tissue lacks the striped patternof striated tissue; it consists of long, spindle-shaped cells.

27BODY TISSUES: HOLDING IT ALL TOGETHER

Where adiposecomes from

Adipose tissue is some-times referred to as fat.The word adipose is de-rived from adiposus, aword with Greek andLatin origins: the Latinprefix adip- and theGreek root aleipha,

which mean fat or oil.


845502.qxd 8/19/08 4:24 PM Page 27

Its activity is stimulated by the autonomic nervous sys-tem and isn’t under voluntary control. Smooth muscle tis-sue lines the wall of many internal organs and otherstructures, such as the walls of arteries and veins.

Nervous tissueThe main function of nervous tissue is communication.Its primary properties are irritability (the capacity to re-act to various physical and chemical agents) and conduc-tivity (the ability to transmit the resulting reaction fromone point to another). Nervous tissue cells may be neu-rons or neuroglia.

Neurons consist of three parts: dendrites, the cellbody, and axons. Like tiny antennas, dendrites receiveimpulses and conduct them into the cell body. Axonscarry impulses away from the cell body.

Neuroglia form the support structure of nervous tis-sue, insulating and protecting neurons. They’re foundonly in the central nervous system.

Organs and systems: The specialists

When a group of tissues handles a more complicated taskthan any one tissue could perform alone, they’re calledorgans.

Organs combine to form systems, which perform amore complex function than any one organ can manageon its own. The body depends on these systems in the fol-lowing ways:• The immune system protects the body from diseaseand invading organisms.• The nervous system and sensory system process in-coming information and allow the body to respond.• Reproduction and urine excretion are managed by thegenitourinary system.• The gastrointestinal system digests and absorbsfood and excretes waste products.• Blood is transported by the cardiovascular system.• The respiratory system maintains the exchange ofoxygen and carbon dioxide in the lungs and tissues andregulates acid-base balance.

28BODY STRUCTURE

Check out

my dendrites.

They receive

and conduct

impulses.

845502.qxd 8/19/08 4:24 PM Page 28

• The integumentary system—which includes skin,hair, nails, and sweat glands—protects the body andhelps regulate body temperature. (See Why call it integu-mentary?) • The muscular system allows the body to move.• The skeletal system supports the body and gives mus-cles a place to attach.• The endocrine system consists of glands that secreteregulating chemicals called hormones.• The circulatory system consists of the heart andblood vessels. Oxygen and other nutrients are transport-ed throughout the body via this system.• The reproductive system includes the organs of re-production, such as the gonads (testes in the male andovaries in the female), which produce germ cells andmanufacture hormones.

Directions, regions, and positions

Determining directions within the body is essential toaccurately pinpoint the locations of structures. Termsthat describe body planes, cavities, and regions are alsouseful.

Giving directionsSpecific terms are used to define the relationship betweenbody areas and the locations of structures. These termsdescribe the body in anatomic position—standing erectwith arms hanging to the side, and palms facing forward:• Superior means above; for example, the knees are su-perior to the ankles.• Inferior means below; for example, the feet are inferi-or to the ankles.• Anterior means front or in front of; for example, thesternum is an anterior structure. Ventral is sometimesused instead of anterior.• Posterior means back or in back of; for example, thespine is a posterior structure. Dorsal may be used in-stead of posterior.• Medial (midline) means toward the center.• Central means in the center.• Peripheral means away from the center. • Lateral refers to the sides, or away from the midline.• Proximal means nearest to.

29DIRECTIONS, REGIONS, AND POSITIONS

Why call itintegumentary?

It’s easy to see why in-

tegumentary is the termfor a body system that in-cludes the hair, skin,nails, and sweat glands.The origin of this word isthe Latin word integu-

mentum, which meansto cover.


845502.qxd 8/19/08 4:24 PM Page 29

• Distal describes a point farthest from the point oforigin.• Superficial describes a point nearest the body surface.• Deep means away from the surface.

Body planes and sectionsThe body is theoretically divided into three areas calledthe sagittal, the frontal (coronal), and the transverseplanes. (See Body reference planes.)

Sagittal planeThe sagittal plane runs lengthwise from front to backand divides the body into right and left sides. A mediansagittal cut produces two equal halves, each containingan arm and a leg. (Don’t try this at home!)

Frontal planeThe frontal plane runs lengthwise from side to side, di-viding the body into ventral and dor-sal (front and back) sections.

Transverse planeThe transverse plane, also called thehorizontal plane, cuts the body intoupper and lower parts. These areknown as the cranial (head) and thecaudal (tail) portions.

Body cavitiesA cavity is a hollow space within the body that usuallyhouses vital organs. The two major cavities are the ven-tral cavity and the dorsal cavity. They’re divided intosmaller spaces for the internal organs. (See Locatingbody cavities, page 32.)

Ventral cavityThe ventral cavity contains the thoracic (chest) cavity andthe abdominopelvic cavity. The thoracic cavity, locatedabove the diaphragm, contains the heart, lungs, and largeblood vessels that join the heart. The abdominopelvic

30BODY STRUCTURE

Plainly speaking,

the body is divided

into three planes:

sagittal, frontal, and

transverse.

845502.qxd 8/19/08 4:24 PM Page 30

cavity, located below the diaphragm, consists of the ab-dominal cavity (stomach, most of the intestines, kidneys,liver, gallbladder, pancreas, and spleen) and the pelvic cav-ity (urinary bladder, rectum, and internal parts of the re-productive system).

Dorsal cavityThe dorsal cavity includes both the cranial and spinalcavities:• The cranial cavity is relatively small; it houses andprotects the brain.• The spinal cavity contains the spinal column andspinal cord.


Body reference planes

Body reference planes are used to indicate the locations of body structures. Here are the mediansagittal, the frontal, and the transverse planes, which lie at right angles to one another.

Frontal plane

Transverse plane

Median sagittal plane

845502.qxd 8/19/08 4:24 PM Page 31

Abdominal regionsSo many organs and structures lie inside the abdominaland pelvic cavities that special terms are used to pinpointdifferent areas. Nine regions are identified from right toleft and top to bottom:• The right hypochondriac region contains the rightside of the liver, the right kidney, and a portion of the di-aphragm.• The epigastric region contains the pancreas and por-tions of the stomach, liver, inferior vena cava, abdominalaorta, and duodenum.• The left hypochondriac region contains a portion ofthe diaphragm, the spleen, the stomach, the left kidney,and part of the pancreas.

32BODY STRUCTURE

Locating body cavities

The dorsal cavity, in the posterior region of the body, is divided into the cranial and vertebralcavities. The ventral cavity, in the anterior region, is divided into the thoracic and abdominopelviccavities.

Thoracic cavity

Abdominopelviccavity

Cranial cavity

Vertebral cavityVentralcavity

Dorsalcavity

845502.qxd 8/19/08 4:24 PM Page 32

• The right lumbar region contains portions of thelarge intestines and the right kidney.• The umbilical region contains sections of the smalland large intestines and a portion of the left kidney.• The left lumbar region contains portions of the smalland large intestines and a portion of the left kidney.• The right iliac (inguinal) region includes portions ofthe small and large intestines.• The hypogastric region’s prominent structures in-clude a portion of the sigmoid colon, the urinary bladderand ureters, and portions of the small intestine.• The left iliac (inguinal) region contains portions ofthe small and large intestines. (See Anterior view of theabdominal regions, page 34.)

PositionsPatients may be placed in several positions for examina-tion, testing, and treatment. (See Picturing positions,page 35.) These positions are described by many terms.The most frequently used include:• Fowler’s—head of bed raised 45 to 60 degrees, withknees slightly flexed• lateral recumbent, or Sims’—lying on the left sidewith the right thigh and knee drawn up• lithotomy—lying on the back with the hips and kneesflexed and the thighs abducted and externally rotated• supine—lying flat on the back• prone—lying face down• Trendelenburg’s—lying flat with thehead lower than the body and legs• knee-chest—on knees with the chestresting on the bed.


The prone position

is the perfect position

for a back massage.

845502.qxd 8/19/08 4:24 PM Page 33

34BODY STRUCTURE

Anterior view of the abdominal regions

This illustration shows the abdominal regions from the front.

The abdomen

is divided like a

tic-tac-toe

board into nine

distinct regions.

Umbilicalregion

Hypogastricregion

Left iliac

region

Left lumbar region

Lefthypochondriac

region

Epigastricregion

Righthypochondriacregion

Right lumbar region

Rightiliacregion

845502.qxd 8/19/08 4:24 PM Page 34

Picturing positions

The illustrations below depict the various positions that the patient may be placed in for examinations, testing, and treatments.


Supine

Sims’

Prone

Fowler’s

Trendelenburg’s

Knee-chest

Lithotomy

Keep in mind that you

should only place your

patient in positions that her

condition allows.

845502.qxd 8/19/08 4:24 PM Page 35

36BODY STRUCTURE

Across

2. Site of adenosine triphosphateproduction5. Only type of cell that undergoesmeiosis6. Name for the structures of a cell8. Growth phase of mitosis11. Type of epithelial tissue thathas three or more layers14. Support structure of nervoustissue

16. The final step of mitosis18. Eponym for a position in whichthe head of the bed is raised andthe patient’s knees are slightlyflexed

Down

1. One of three body referenceplanes3. Eponym for a position in whichthe patient’s head is lower than hisbody or legs4. Cell movement7. Word that means in front of9. When solutes move from anarea of higher concentration to anarea of lower concentration

10. Largest organelle12. Type of tissue in which a fatdroplet occupies most of the cell13. Process of cell division fromthe Greek word for thread15. Passive transport methodwhose root comes from the Greekword meaning to push17. Physicist to first coin the termcell


Vocabulary builders

At a crossroadsCompleting this crossword puzzle will help build your medicalvocabulary. Good luck!

1 2 3 4

5

6

7 8

9

10 11 12

13

14 15

16 17

18

845502.qxd 8/19/08 4:24 PM Page 36


Match gameTissues are groups of similar cells that perform the same role. Each tissue also has atleast one unique function. Match each clue to the correct type of tissue.

Clues

1. Tissue that lines the surface of serous mem-branes, such as the pleura, pericardium, andperitoneum

2. Epithelial tissue that has only one layer ofcells but appears to have more

3. Tissue that has cube-shaped surface cells

4. Tissue that has large spaces that separatethe fibers and cells and contains a lot of inter-cellular fluid

5. Tissue with a striped appearance

6. Nervous tissue that consists of three parts:dendrites, cell body, and axons

Choices

A. Loose connective

B. Mesothelium

C. Neurons

D. Pseudostratified

E. Cuboidal

F. Striated muscle

Knowing the

different tissue types

brings you one step

closer to mastering

anatomy.


845502.qxd 8/19/08 4:24 PM Page 37

O see, can you say?Sound out each group of pictures and symbols below to reveal a term that wasreviewed in the chapter.

38BODY STRUCTURE


1.

2.

3.

This is easy!

Even long, medical

words are simply

a sum of their

parts.

845502.qxd 8/19/08 4:24 PM Page 38



1. ____ ____ ____ ____ ____ ____ ____ ____ ____

2. ____ ____ ____ ____ ____ ____ ____

3. ____ ____ ____ ____ ____ ____ ____ ____ ____

4. ____ ____ ____ ____ ____ ____ ____

5. ____ ____ ____ ____ ____ ____ ____ ____

6. ____ ____ ____ ____ ____ ____

1. This is an aqueous mass that is surrounded by the cell membrane. 2. Only gametes (ova and spermatozoa) undergo this type of reproduction. 3. Particles or solutes move from an area of higher concentration to an areaof lower concentration in this type of movement.4. The cavity that houses and protects the brain.5. This plane runs lengthwise front to back and divides the body into right andleft sides. 6. This prefix means false.


I’m hungry…and I need

something other than a

knife and fork! Which

organelle is responsible

for helping me digest

foreign material?

845502.qxd 8/19/08 4:24 PM Page 39

40BODY STRUCTURE

1. B; 2. D; 3. E; 4. A; 5. F; 6. C

Match game

1. Mitochondria; 2. Cytokinesis; 3. Meiosis

O see, can you say?

1. Cytoplasm; 2. Meiosis; 3. Diffusion; 4. Cranial; 5. Sagittal; 6. PseudoAnswer to puzzle—Lysosome

Talking in circles

At a crossroads

Answers

1S

2M I

3T O

4C H O N D R I A

A R Y5G A M E T E T

I N6O R G A N E L L E S

T D K

T7A E

8I N T E R P H A S E

A N L N

L T E E9D

10N E N

11S T R

12A T I F I E D

U R B I D F

C I U S I F13M

L O R P U I14N E U R

15O G L I A O S T

U S S I O

S M16T E L O P

17H A S E

18F O W L E R N O I

S O S

I K

S E

845502.qxd 8/19/08 4:24 PM Page 40

Anatomy of the skeleton

The 206 bones of the skeletal system carry out six impor-tant anatomic and physiologic functions:

They protect internal tissues and organs; for exam-ple, the 33 vertebrae surround and protect the spinalcord, brain, and heart.

They stabilize and support the body.

They provide surfaces for muscle, ligament, and ten-don attachment.

They move through lever action when contracted.

They produce red blood cells (RBCs) in the bonemarrow (a process called hematopoiesis, from theGreek haima, or blood, and poiesis, meaning makingor forming).

They store mineral salts; for example, approxi-mately 99% of the body’s calcium. (See Pronouncing keyskeletal terms, page 42.)

3

Health assessmentSkeletal system

Just the facts


♦ terminology related to the anatomy of the skeletalsystem

♦ terminology needed for physical examination of theskeletal system

♦ tests that help diagnose skeletal system disorders

♦ disorders of the skeletal system and their treat-ments.

845503.qxd 8/19/08 4:34 PM Page 41

Bones-r-usThe skeleton is divided into two parts: the axial (fromthe Latin axis, meaning axle or wheel) and appendicu-lar (from the Latin appendare, meaning to add or ap-pend). The axial skeleton forms the body’s vertical axisand contains 74 bones in the head and torso; it also in-cludes 6 bones of the middle ear, for a total of 80 bones.(See The body’s bones.)

42SKELETAL SYSTEM

Below is a list of key terms, along with the correct way topronounce them.


Pronouncing key skeletal terms

Acetabulum

Arthrocentesis

Arthrodesis

Astragalus

Calcaneus

Canaliculi

Cartilaginous

Coccyx

Costochondritis

Hematopoiesis

Hyaline

Kyphosis

Lambdoid

Malleolus

Medullary

Occipital

Periosteum

Xiphoid process

AS-UH-TAH-BYOU-LUHM

AR-THROH-SEN-TEE-SIS

AR-THROD-UH-SIS

AS-TRAG-UH-LUHS

KAL-KAY-NEE-UHS

KAN-UH-LIK-YOU-LEYE

KAR-TUH-LAJ-UH-NUHS

KOK-SIKS

KOS-TOH-KON-DREYE-TIS

HEE-MUH-TOE-POY-EE-SIS

HEYE-UH-LIN

KEYE-FOH-SIS

LAM-DOYD

MAH-LEE-OH-LUHS

MED-UH-LAIR-EE

OK-SIP-UH-TUHL

PER-EE-OS-TEE-UHM

ZEYE-FOYD PRAH-SESS

845503.qxd 8/19/08 4:34 PM Page 42

43ANATOMY OF THE SKELETON

The human skeleton contains 206 bones; 80 form the axial skeleton and 126 form the appendicular skeleton. The illustrations belowshow some of the major bones and bone groups.


The body’s bones

Frontal

Maxilla

Mandible

Clavicle

Manubrium(MA-NOO-BREE-UHM)

Sternum

Humerus(HYOU-MER-UHS)

Ulna

Radius

Iliac crestGreater trochanterCarpalsMetacarpalsPhalanges

Femur

Patella

Pubis

Tarsals

Metatarsals

Phalanges

Anterior view

Occipital

Cervical vertebrae (7)

Acromial processScapula

Thoracic vertebrae (12)

Ribs

Lumbar vertebrae (5)

Ilium(IL-EE-UHM)Sacrum

Ischium(IS-KEE-UHM)

Coccyx

Tibia

Fibula

Posterior view

845503.qxd 8/19/08 4:34 PM Page 43

The appendicular skeleton contains 126 bones andincludes the body’s appendages, or upper and lower ex-tremities.

The axial skeletonThe axial skeleton forms the long axis of the body and in-cludes bones of the skull, vertebral column, and rib cage.

The skullThe skull contains 28 irregular bones in two major areas:the brain case, or cranium (from the Greek kranion,meaning upper part of the head), and the face. Eightbones form the cranium, 14 bones make up the face, andthe inner ears contain 6 ossicles (from the Latin ossicu-lum, meaning bone), or 3 small bones in each ear. Thejaw bone, or mandible (from the Latin mandibula,meaning jaw) is the only movable bone in the skull. (SeeBones of the skull.)

Getting it togetherSutures are immobile joints that hold the skull bones to-gether. The coronal suture unites the frontal bone andthe two parietal bones. In infants, this suture isn’t closed,leaving a diamond-shaped area (called the anteriorfontanel), which is covered only by a membrane. Thissoft spot closes between ages 10 and 18 months. At theback of the head of infants, the posterior fontanel clos-es by age 2 months. (See Little fountain.)

A real airheadSinuses are air-filled spaces within the skull that lessenthe bone weight, moisten incoming air, and act as res-onating chambers for the voice.

Up frontThe sinuses, the forehead, and the area directly behind itare part of the frontal bone. This bone also forms theorbits (eye sockets) and the front part of the cranialfloor.

Take it from the topThe main part of the skull consists of a number of bonessutured together:

44SKELETAL SYSTEM

Little fountain

Fontanel, also spelledfontanelle, derives fromFrench and means littlefountain. It can also referto any membrane-covered area betweentwo bones.


845503.qxd 8/19/08 4:34 PM Page 44

• The coronal suture connects the frontal bone with theparietal bones.• Two parietal bones crown the head, forming the roofand the upper part of each side of the skull.• The squamous suture connects the parietal boneswith the temporal bones.• Temporal bones form the lower part of the sides ofthe skull and part of its floor. They contain structures ofthe middle and inner ear and the mastoid sinuses.


The skull is a complex bony structure. It’s formed by two sets of bones, the cranial bones and the facial bones.


Bones of the skull

Squamous suture(SKWAY-MUHS)

Parietal bone

Lambdoid suture

Temporal bone

Occipital bone

Coronal suture

Frontal bone

Sphenoid bone(SFEE-NOYD)

Orbit

Nasal bone

Malar (zygomatic) bone(MAY-LAHR[ZEYE-GOH-MAT-IK])Maxilla

Mandible

845503.qxd 8/19/08 4:34 PM Page 45

• The lambdoid suture connects the parietal bones tothe occipital bone.• The occipital bone forms the rear portion and thebase of the skull and forms a movable joint with the firstcervical vertebra.• A large opening at the base of the occipital bone, calledthe foramen magnum (meaning large hole), allows thespinal cord to pass from the encephalon into the spine.

A bat in the belfryThe sphenoid bone looks like a bat with outstretchedwings and legs extended to the back. Located in the cra-nial floor, this bone is an anchor for the frontal, parietal,occipital, and ethmoid bones. It also supports part of theeye sockets and forms the lateral walls of the skull. Thesphenoid sinuses are large air-filled spaces within thesphenoid bone.

Facial bonesThe bones of the face include:• two maxillary bones that form the upper jaw, nose,orbits, and roof of the mouth as well as the maxillary si-nuses• the cheekbones, called zygomatic or malar bones,that attach to chewing muscles• two nasal bones that form the upper part of the bridgeof the nose (cartilage forms the lower part)• the mandible that forms the lower jaw• two lacrymal bones that contain the lacrymal bag(part of the conduit through which tears drain in thenasal cannula)• the vomer that’s part of the nasal septum• two palatine bones that form the posterior portion ofthe hard palate, lateral side of the nasal cavity, and smallpart of the orbit.

The spinal columnThe flexible spinal column contains 24 vertebrae (pluralof vertebra), the sacrum, and the coccyx. (See Somethorny words of the spine.)

Joints between the vertebrae allow forward, back-ward, and sideways movement. The spinal column sup-ports the head while suspending the ribs and organs in

46SKELETAL SYSTEM

Memoryjogger

As a way toremember

the bones of theskull, use your headand think “part ofman”:

PARietal

Temporal

Occipital

Frontal

MAlar

Nasal.

Joints between

the vertebrae allow

forward, backward,

and sideways

movement. Not all

at once, though!

845503.qxd 8/19/08 4:34 PM Page 46

front. It also anchors the pelvic girdle and provides at-tachment points for many important muscles. The spinalcolumn contains:• seven cervical (neck) vertebrae, which support theskull and rotate• twelve thoracic (chest) vertebrae, which attach to theribs• five lumbar (lower back) vertebrae, which support thesmall of the back• the sacrum, a single bone that results from the fusionof five vertebrae and attaches to the pelvic girdle• the coccyx, or tailbone, which is located at the bottomtip of the spinal column and is a single bone formed fromthe fusion of four or five vertebrae.

The spinal column is curved to increase its strengthand make balance possible in an upright position. Thevertebrae are cushioned by intervertebral disks com-posed of cartilage. (See A look at the spinal column,page 48.)


Spine comes from the Latin word spina, which means thorn, andis related to spike as well. Latin writers likened the thorn to theprickly bones in animals and fish and, thus, the word also be-came the designation for the vertebral column.

Vertebra and spondylo

Also from Latin, vertebra derives from a verb meaning to turn.Therefore, it formerly connoted any joint—not just those of thespine. A Greek word, spondylos, has the same meaning as verte-

bra. It shows up in words like spondylitis, which is an inflamma-tion of the vertebrae.

Sacrum and coccyx bringing up the rear

The sacrum was formerly known as the os sacrum, literally theholy bone, so called because it was thought to be a particularlychoice bit and so was offered to the gods in sacrifice. The coc-

cyx derives its name from the Greek word for the cuckoo,kokkyx. The Greek anatomist Galen thought this triangular boneresembled the shape of the bird’s bill.


Some thorny words of the spine

845503.qxd 8/19/08 4:34 PM Page 47

48SKELETAL SYSTEM

The 33 vertebrae of the spinal column surround and protect thespinal cord. They’re divided into five sections: cervical vertebrae,thoracic vertebrae, lumbar vertebrae, sacrum, and coccyx.


A look at the spinal column

Cervical vertebrae (7)

Thoracic vertebrae (12)

Lumbar vertebrae (5)

Sacrum

Coccyx(KOK-SIKS)

Yep. I have 33

vertebrae—and

they’re all perfect

specimens, if I do

say so myself.

845503.qxd 8/19/08 4:34 PM Page 48

SternumLocated in the center of the chest, the sternum is a flat,sword-shaped bone that’s attached to the clavicles (collar-bones) and the innermost part of the first two pairs of ribs.

Caged inThe sternum, ribs, and thoracic vertebrae form a protec-tive enclosure around the vital organs. Known as thethoracic cage, or thorax, this flexible structure protectsthe heart and lungs and allows the lungs to expand dur-ing respiration.

RibsThe flat, curved bones attached to the thoracic portion ofthe spinal column are called ribs.

Ribs—true or false?The term costal refers to ribs. The first seven pairs of ribsare attached to the sternum by costal cartilage; they’recalled true ribs. The remaining five pairs of ribs arecalled false ribs because they aren’t attached directly tothe sternum. All ribs are independently attached to thespinal column.

Appendicular skeletonThe appendicular skeleton includes the upper and lowerextremities.

The upper extremitiesThe clavicles, or collarbones, are two flat bones at-tached to the sternum on their anterior side and to thescapulae (shoulder blades) laterally. This forms thesternoclavicular joint.

The scapulae are a pair of large, triangular bones thatare located at the back of the thorax. These bones, plusthe clavicles, form the shoulder girdles.

Armed and dangerousThe humerus, or upper arm bone, is a long bone with ashaft and two bulbous ends. The two long bones of thelower arm are the ulna, located on the little finger side ofthe humerus, and the radius, on the thumb side. These


The ulna and the

radius articulate with

the humerus to form

the elbow joint.

845503.qxd 8/19/08 4:34 PM Page 49

bones articulate with the humerus to form the elbowjoint. The wrists are composed of eight small, irregularcarpal bones aligned in two rows. Ligaments bind thecarpals together.

50SKELETAL SYSTEM

A view of the right hand, illustrating the positions of the carpals, metacarpals, and phalanges.


Bones of the hand

Trapezium

Phalanges(fingers)(FUH-LAN-JEZ)

Metacarpals(palm)(MET-UH-KAR-PUHLS)

Carpals(wrist)

Distal

Middle

Proximal

845503.qxd 8/19/08 4:34 PM Page 50

A handful of termsThe bones of the hand are comprised of metacarpalbones and phalanges. (See Bones of the hand.)

The way these bones come together enables move-ment of the hand:• Five small long metacarpal bones attach to the carpalsand form the palm of the hand.• Phalanges, or finger bones, are miniature long bones.Each finger has three phalanges, while the thumb hastwo. (See A phalanx of phalanges.)• The thumb metacarpal has a freely movable joint, allow-ing a wide range of movement between the thumb meta-carpal and the trapezium, the carpal at the base of thethumb.

Lower extremitiesThe lower extremities contain bones of the hip, thigh, leg,ankle, and foot.

Girdle wordsThree pairs of bones fuse during childhood to form thepelvic girdle, the broadest bone in the body. This bonesupports the trunk, protects the abdominal organs withinits basin, and attaches the lower extremities to the body.The three pairs of fused bones include the ilium, whichis the largest and uppermost of the three; the ischium, thelower and strongest set of bones; and the pubis, a pair ofanterior bones that meet at the symphysis pubis—a car-tilaginous joint.

Give ’em a leg upThe two femurs, or upper leg bones, are the longest andheaviest bones in the body. They connect at the proximalend with the hip, articulating with the acetabulum, orhip socket. The femurs connect with the tibia at the dis-tal end. The kneecap, or patella, is a small, flat bone thatprotects the knee joint and overlaps the distal end of thefemur and the proximal end of the tibia.

Below the kneeThe tibia, sometimes called the shinbone, is the largestand strongest of the lower leg bones. It articulates withthe femur at the proximal end and meets the fibula and


A phalanx ofphalanges

Phalanges is the pluralof the Greek word pha-

lange, or phalanx. Thelatter term was appliedto Greek and Romanarmy troop formations,noted for their closelyjoined and unified ma-neuvers.


It says here that

the word patella, for

kneecap, is a Latin

word that means a

small, flat dish—just

what the kneecap

looks like.

845503.qxd 8/19/08 4:34 PM Page 51

the talus at the distal end. The fibula connects with thetibia at its proximal and distal ends. The fibula’s distalend also articulates with the talus. The articulation of thefibula, tibia, and talus bones creates the bony prominenceon the outside of the ankle, called the lateral malleolus.

Now, fleetly, to the footThe foot bones form a strong, stable arch with lengthwiseand crosswise support. Strong ligaments and tendons ofthe leg muscles help the foot bones maintain their archedposition:• Seven short tarsal bones structurally resemble thewrist, and they articulate with the tibia and fibula:– The talus bone (astragalus) forms part of the anklejoint.– The heel, called the calcaneus, is the largest tarsalbone.– The scaphoid bone is also called the navicular becauseof its boat shape.– The cuneiforms (the lateral, intermediate, and me-dial) are three wedge-shaped bones that form the arch ofthe foot.– The cuboid bone articulates in the front with themetatarsal bones.• Five metatarsal bones form the foot and articulatewith the tarsal bone and the phalanges.• The fourteen phalanges (toes) are similar to fingers,with three bones in each toe except the great toe, which,like the thumb, contains only two bones.

Anatomy of bones

Bones are classified according to their shape:• Long bones are the main bones of the limbs, exceptthe patella, and those of the wrists and ankles.• Short bones are the bones of the wrists and ankles.• Flat bones include the sternum, scapulae, and cranium,among others.• Irregular bones include the vertebrae and hip bones.

Boning up on bone materialAll bones consist of two types of bone material: an outerlayer of dense, smooth compact bone and an inner layer

52SKELETAL SYSTEM

Words will never

hurt me. But let’s

keep sticks and

stones out of it!

845503.qxd 8/19/08 4:34 PM Page 52

of spongy, cancellous (porous) bone. Compact bone isfound especially in the shaft of long bones and in the out-er layers of short, flat, and irregular bones. Cancellousbone fills the central regions of the epiphysis (the end ofa long bone where bone formation takes place) and theinner portions of short, flat, and irregular bones.

Along the long bonesLong bones contain a number of visible, common struc-tures:• diaphyses (singular: diaphysis)—the long, narrowshaft of the bone contains the bone marrow and has twoirregular ends• epiphyses (singular: epiphysis)—the bulbous ends oflong bones that provide a large surface for muscle attach-ment and give stability to joints• articular cartilage—a thin layer of hyaline cartilagethat covers and cushions the articular (joint) surfaces ofthe epiphyses• periosteum—a dense membrane that covers the shaftsof long bones; it consists of two layers: a fibrous outer layerand a bone-forming inner layer containing osteoblasts(bone-producing cells) and osteoclasts (bone-destroyingcells)• medullary cavity—a cavity filled with bone marrow• endosteum—a thin membrane that lines the medullarycavity and contains osteoblasts and osteoclasts.

Feeding the long bonesWithin compact bone are haversian systems. (SeeHaversian diversion.) The haversian systems are madeup of the following structures:• lamellae—thin layers of ground substance• lacunae—small hollow spaces that contain osteocytes• canaliculi—small canals• haversian canals—central canals that contain bloodand lymph vessels, nerves and, sometimes, marrow.

Blood reaches bone by arterioles in haversian canals;by vessels in Volkmann’s canals, which connect onehaversian canal to another and to the outer bone; and byvessels in the bone ends and within the marrow. (See Twoviews of a long bone, page 54.)

53ANATOMY OF BONES

Haversiandiversion

The haversian systems

were named in honor ofthe 17th century Britishdoctor and anatomistClopton Havers, who dis-covered them.


845503.qxd 8/19/08 4:35 PM Page 53

To marrow, and to marrow, and to marrow…In a child’s body, nearly all the bones contain red bonemarrow. In an adult, red bone marrow is found in the fe-mur, ribs, vertebrae, and the ends of the humerus in theupper arm. Red bone marrow performs hematopoiesis,making new RBCs for the body.

Bone growth and resorptionBones grow both in length and in thickness. At the epi-physes, they grow longer; at the diaphyses, they grow indiameter through the activity of osteoblasts in the perios-

54SKELETAL SYSTEM

Here’s a look at a long bone from interior and cross-section views.


Two views of a long bone

Diaphysis(DEYE-AF-EH-SIS)

Concentric lamellae(LAH-MEL-LEE)

Haversian system(HAH-VER-SHUHN)

Osteocytes withinlacunae(LAH-KOO-NEE)Canaliculi

Vessel in haversiancanal

Volkmann’s canal

Trabeculae(TRAH-BEK-YOU-LEE)

Articular cartilage

Cancellous bone

Epiphyseal line

Compact bone

Blood vessel intomarrow

Endosteum

Periosteum (toughfibrous membranesheath)

Epiphysis(EH-PIF-UH-SIS)

Internal view of long bone

Cross section of long bone

Cancellous bone Compact bone

845503.qxd 8/19/08 4:35 PM Page 54

teum. A hormone secreted by the anterior lobe of the pi-tuitary gland controls bone growth. (See Bone up onosteo- and oss-.)

As osteoblasts add new tissue to the outside of abone, large phagocytic cells called osteoclasts eat awaybony tissue in the medullary cavity to keep the bone frombecoming too thick. A healthy bone is constantly brokendown, resorbed, and repaired long after it stops growingin size. During adulthood, bone formation (or ossifica-tion) and bone resorption balance one another so thateach bone remains a constant size. During childhood andadolescence, ossification is faster than resorption andbones grow larger.

CartilageBones and joints need support as well as shock absorp-tion. Cartilage is a dense connective tissue that hasthese capabilities. It consists of fibers embedded in astrong, gel-like substance. Unlike rigid bone, cartilage hasthe flexibility of firm plastic.

Cartilage supports and shapes various structures,such as the auditory canal and the intervertebral disks. Italso cushions and absorbs shock. Cartilage has no bloodor nerve supply.

Types of cartilageCartilage may be fibrous, hyaline, or elastic:

55ANATOMY OF BONES

Osteon, Greek for bone, provides a key word-forming root for medical terms relating to bones, oste- or osteo-. Osteoblast is a com-pound of osteo- and -blast; the latter is another common medical root derived from a Greek word that means a bud or a shoot of adeveloping organism. An osteoblast is thus a cell that buds forth new bone tissue. The Greek word clast, on the other hand, meansto break or fragment. Therefore, an osteoclast is a cell that breaks down bone.

The Romans had a name for it

Another very common root for forming words is the Latin word os, or oss-, also meaning bone. This root is contained in words likeossify, meaning to change or to become bone, and ossification, the process of becoming bone.


Bone up on osteo- and oss-

845503.qxd 8/19/08 4:35 PM Page 55

• Fibrous cartilage forms at the meniscus and the inter-vertebral disks.• Hyaline cartilage covers articular bone surfaces(where one or more bones meet at a joint), connects theribs and sternum, and appears in the trachea, bronchi,and nasal septum.• Elastic cartilage is located in the auditory canal, ex-ternal ear, and epiglottis.

Bone movementBones are rigid structures that can’t bend without beingdamaged, so individual bones move at joint sites, or ar-ticulations. Every bone in the body except the hyoidbone, which anchors the tongue, is connected to anotherbone by flexible connective tissue.

Classifying jointsJoints can be classified by the type of movement they al-low and by their structure.

How does it move?The three classes of joints identified by the range ofmovement they allow are:• synarthrosis—immovable• amphiarthrosis—slightly movable• diarthrosis—freely movable.

What is it made of?By structure, a joint may be classified as fibrous, carti-laginous, or synovial. In fibrous joints, the articular sur-faces of the two bones are bound closely by fibrous con-nective tissue and little movement is possible. The cranialsutures are examples of fibrous joints.

In cartilaginous joints, cartilage connects one boneto another; these joints allow slight movement. An exampleis the symphysis pubis (the junction of the pelvic bones).

Body surfaces in the synovial joints are covered byarticular cartilage and joined by ligaments (dense,strong, flexible bands of fibrous connective tissue thatbind bones to other bones) lined with synovial mem-brane. Freely movable, synovial joints include most jointsof the arms and legs. Synovial joints also include an ar-ticular capsule—a saclike envelope, whose outer layer

56SKELETAL SYSTEM

Our joints

are jumpin’! It

must be that

diarthrosis.

845503.qxd 8/19/08 4:35 PM Page 56

is lined with a vascular synovial membrane. This mem-brane contains synovial fluid—a viscid fluid, produced bythe synovial membrane that lubricates the joint.

Small bursae (singular: bursa) are synovial fluidsacs located at friction points of all types of joints as wellas between tendons, ligaments, and bones. Bursae cush-ion these structures and decrease stress on adjacentones. (See The bag for bones.)

Synovial subdivisions—joints to live inBased on their structure and the type of movement, sy-novial joints fall into various subdivisions:• Gliding joints, such as the wrists and ankles, allowadjacent bone surfaces to move against one another.• Hinge joints, such as the elbows and knees, permitmovement in only one direction.• Pivot joints, also called rotary joints or trochoidjoints, allow a movable bone to pivot around a station-ary bone. The neck and elbows contain pivot joints.

Knuckleheads• Condylar, or knuckle joints, contain an oval head ofone bone that fits into a shallow depression in a secondbone. The union between the radius (arm bone) and thecarpal bones of the hand is an example of a condylarjoint.• Saddle joints resemble condylar joints but allowgreater freedom of movement. The only saddle joints inthe body are the carpometacarpal joints of the thumb.• Ball-and-socket joints (spheroid joints) get theirname from the way their bones connect—the sphericalhead of one bone fits into a socket of another bone. Thehip and shoulder joints are the only ball-and-socket jointsin the body.

Physical examination terms

When a patient seeks medical help for a skeletal problem,it’s usually because of a physical mishap. Here are someterms related to examination of the skeletal system thatyou’ll need to know:• angular—at an angle• circular—circlelike or round

57PHYSICAL EXAMINATION TERMS

The bag forbones

You may notice that theword bursa sounds a bitlike the word purse.

That’s more than a coin-cidence. Both wordscome from the Latinword bursa, whichmeans a small bag orsac.

In the body, bursaeare sacs of synovial fluidthat cushion skeletalstructures, such as ten-dons, ligaments, andbones.


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• crepitus—a cracking noise or the sensation that’scommonly felt when the hand is placed over a fracturesite and the broken bone ends are moved• posture—the position of the limbs or the body as awhole• range of motion—the total degree of motion or jointmovement• symmetry—equality of two sides of the body.

Movement and range of motionCommon terms used to describe movement and range ofmotion in joints include:• abduction—moving away from the midline• adduction—moving toward the midline• circumduction—moving in a circular manner• extension—straightening or increasing the joint angle• flexion—bending or decreasing the joint angle• pronation—turning downward• internal rotation—turning toward midline• external rotation—turning away from midline• supination—turning upward.

Common complaintsPatients with joint injuries usually complain of pain,swelling, or stiffness, and they may have noticeable de-formities. A deformity can also occur with a bone frac-ture, which causes sharp pain when the patient movesthe affected area.

Common terms used to describe patient complaintsinclude:• arthralgia—pain in a joint• arthredema—joint swelling• arthropyosis—pus formation in a joint cavity• bursitis—inflammation of a bursa, the fluid-filled sacthat prevents friction within a joint• chondralgia—pain originating in the cartilage• chondritis—inflammation of the cartilage• chondromalacia—abnormal softening of the cartilage• coxitis—inflammation of the hip joint• epiphysitis—inflammation of the epiphysis of a bone• hemarthrosis—blood in a joint cavity

58SKELETAL SYSTEM

Remembering what

arthralgia is can be

easy when you break

it apart: arthr- is the

root for joint; -algia is

the suffix for pain.

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• hydrarthrosis—accumulation of watery fluid in a jointcavity

• kyphosis—the Greek word for hunchback, an abnor-mally increased convexity in the curvature of the thoracicspine• lordosis—forward curvature of the lumbar spine; alsoknown as sway back• lumbago—pain in the lower back (lumbar) region• ostealgia—bone pain• osteitis—inflammation of bone• osteochondritis—inflammation of bone and cartilage• osteolysis—degeneration of bone from calcium loss.

Diagnostic tests

Tests to determine bone and joint diseases or injuries in-clude blood tests, aspiration tests, and radiologic tests.

Blood testsSeveral blood tests help determine bone and joint disor-ders:• Alkaline phosphatase (ALP) is an enzyme producedby the bones and liver. Because blood concentrations ofALP rise with increased activity of bone cells, high ALPlevels help diagnose bone disorders.• Erythrocyte sedimentation rate (ESR) is the rate atwhich RBCs settle in a tube of unclotted blood. An elevat-ed ESR indicates inflammation.• Rheumatoid factor is a blood test used to distinguishrheumatoid arthritis from other disorders.• Serum calcium measures the amount of calcium in theblood. Abnormally high levels are present with Paget’sdisease and other diseases of the bone.

Aspiration testsAspiration tests use fluid withdrawn by a suction device,usually a needle:• In arthrocentesis, a joint is surgically punctured witha needle to aspirate synovial fluid for analysis or to removeaccumulated fluid. (See Simplifying arthrocentesis.)

59DIAGNOSTIC TESTS

Simplifyingarthrocentesis

Arthrocentesis becomesa simple compound wordwhen its componentsare understood. Arthro-

comes from the Greekword arthron, whichmeans joint, and-centesis derives fromthe Greek word kentesis,

which means puncture.So arthrocentesis mustbe a joint puncture.


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• In bone marrow aspiration, a needle is forcedthrough the outer cortex of a flat bone—such as the ster-num or iliac crest—and bone marrow is aspirated foranalysis.• In lumbar puncture, a needle is inserted into the sub-arachnoid space surrounding the spinal cord to remove asample of cerebrospinal fluid.

Radiologic tests• Bone X-ray, the simplest radiologic procedure, is usedto examine a bone for disease or fracture.• A computed tomography (CT) scan, or computer-ized tomography scan, is a series of X-ray photographsthat represent cross-sectional images of the bone. Theseimages are translated by a computer and displayed on anoscilloscope. (See Cat’s tale.)• Arthrography employs contrast dye to observe the in-terior of a joint, such as the knee, shoulder, ankle, or el-bow. Dye is injected into the joint space, and a CT scanrecords images of the joint.• Bone densitometry is a noninvasive technique inwhich X-rays are used to measure bone mineral densityand identify the risk of osteoporosis. The results are ana-lyzed by computer to determine bone mineral status.• A bone scan helps detect bony metastasis, benign dis-ease, fractures, avascular necrosis, and infection. AfterI.V. administration of a radioactive material, a counter de-tects the gamma rays, indicating areas of increased up-take, suggesting an abnormality.• Myelography is a radiographic examination of thespinal cord following injection of a contrast medium.

Procedures• Arthroscopy is also used to observe the interior of ajoint—most commonly the knee. A fiberoptic viewingtube is inserted directly into the joint, allowing a doctorto examine its interior.• A bone marrow biopsy removes a piece of bone con-taining intact marrow.• Magnetic resonance imaging uses an electromagnet-ic field and radio waves to transfer visual images of softtissue, such as tendons, to a computer screen.

60SKELETAL SYSTEM

Cat’s tale

You may also hear a CT

scan referred to as aCAT scan, which is shortfor computed axial to-mography.

The realworld

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Disorders

Disorders of the skeletal system include fractures, dislo-cations, herniations, cancer, and other diseases.

Fractures and other injuriesFractures, traumatic injuries or breaks in bone tissue,most commonly occur in the long bones of the arms andlegs. They can occur in all age-groups in any portion ofthe skeletal system. Fractures can be caused by direct in-jury or can occur spontaneously when bone is weakenedby disease; the latter is called a pathologic fracture.Closed (simple) fracture is seen when the broken bonedoesn’t protrude through the skin. Open (compound)fracture occurs when the bone breaks through the skin,causing tissue damage.

Fracture featuresFractures can be classified according to the bone frag-ment position or by the fracture line:• Colles’ fracture—a fracture of the radius at the lowerend of the wrist in which the bone fragment is displacedbackward• linear fracture—a fracture that runs along the longaxis of a bone• comminuted fracture—a bone is broken into two ormore fragments• greenstick fracture—involves a break in only onepart of the bone thickness• transverse fracture—the fracture line is perpendicu-lar to a bone’s long axis• spiral fracture—the fracture line goes around, or spi-rals, the bone.

Bone away from homeA dislocation is the displacement of a bone fromits normal position within the joint. It can occur atbirth, called a congenital dislocation, or may becaused by a disease or trauma. With a dislocation,joint tissue is torn and stretched, possibly rupturingblood vessels. Subluxation, partial dislocation

61DISORDERS

It’s simple. A

closed fracture

occurs when the

bone doesn’t break

through the skin.

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that separates the joint’s movable surfaces, occurs mostcommonly in the shoulder, hip, and knee.

Don’t play this diskHerniated disk, a ruptured area in the cartilage thatcushions the intervertebral disks of the spinal column, isa painful condition. The soft, central cartilage balloonsout from the disk and puts pressure on the nerve roots.Herniation can happen suddenly with lifting or twistingor may result from degenerative joint disease and otherchronic conditions.

Don’t be callous about bunionsHere are some other injuries related to the skeletal sys-tem that you may encounter:• Bunions are localized areas of swelling that occur onthe foot near the joint of the big toe. They’re caused byinflammation and fibrosis of the bursae.• Calluses are hard bone formations that may occur atthe site of bone fractures.

DiseasesSome of the most common diseases of the skeletal systemand terms to describe skeletal disorders are presentedhere:• Ankylosing spondylitis is a slow, progressive inflam-matory disease of the spine, the sacroiliac joint, and thelarger joints of the extremities (hips, knees, and shoul-ders) that leads to a fibrous or bony ankylosis (immobili-ty) and deformity.• Osteoarthritis, also known as degenerative arthri-tis, affects the joints of the hand, knee, hip, and verte-brae. It’s a major cause of disability.• Osteomalacia is softening of the bones that’s charac-terized by inadequate mineralization of newly formedbone matrix due to vitamin D deficiency; it’s the adultform of rickets.• Osteomyelitis is an inflammation of the bone, bonemarrow, and surrounding soft tissue that’s caused bypyogenic (pus-producing) bacteria.• Osteoporosis is a disorder in which bone mass is re-duced, leading to enhanced bone fragility and an in-creased fracture risk.

62SKELETAL SYSTEM

Oh my!

Osteomyelitis is an

inflammation of the

bone, bone marrow, or

soft tissue that’s

caused by bacteria.

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• Rickets is a condition of abnormal bone growth inchildren caused by insufficient vitamin D, calcium, andphosphorus.• Rheumatoid arthritis is a chronic autoimmune disor-der that affects the synovial membranes. Painful inflam-mation of the joints may lead to crippling deformities andaffect many organ systems.• Scurvy is a condition caused by lack of vitamin C inthe diet, which results in abnormal bones and teeth.

Bone tumorsBone tumors can be benign (noncancerous) or malig-nant (cancerous). Here are some tumor types:• Osteochondroma is a common tumor that causes pro-jections (spurs) at the end of long bones, especially theknees, ankles, hips, shoulders, and elbows. (See Tumorterm.)• Osteosarcoma is a fast-growing malignant tumor ofskeletal tissue with a high mortality rate. Common sitesof involvement are the tibia, femur, and humerus. This tu-mor commonly metastasizes to the lungs.• Chondrosarcoma is a large, slow-growing malignanttumor that affects the hyaline cartilage. It occurs most of-ten in the femur, spine, pelvis, ribs, or scapulae.

Treatments

Noninvasive treatment for bone and joint injuries in-cludes:• a splint, which is a removable appliance that immobi-lizes, restrains, and supports the injured or displacedbody part• a cast, which is a rigid dressing that’s placed around aninjured body part to support, immobilize, and protect itand promote healing• a closed reduction, which is a manual alignment of afracture and may precede the application of a cast• traction, which uses a system of weights and pulleysto immobilize and relieve pressure on a fractured bone tomaintain proper position and to facilitate healing.

63TREATMENTS

Tumor term

The word for a bone tu-mor begins with thecommon root osteo-,

meaning bone. Chondr-

is a root meaning carti-lage, and -oma is a suffixmeaning tumor. Osteo-

chondroma is thus a tu-mor of the bone and car-tilage.


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Bones, bones—a fixation on bonesSome fractures require internal fixation devices, suchas pins, plates, screws, wires, and surgical cement, to sta-bilize the bone fragments. An open reduction with in-ternal fixation is a surgical procedure that allows thesurgeon to directly align the fractured bone and apply in-ternal fixation devices. (See Let’s reduce that reduction.)

Cut to the boneThese terms relate to invasive treatment of joints andbones:• Arthrectomy is the excision of a joint.• In arthrodesis, a bone graft (typically from the pa-tient’s iliac crest) is used to fuse joint surfaces; it’s calledspondylosyndesis when this procedure is applied to thevertebrae. (See Spelling out spondylosyndesis.)• Arthroplasty surgically reconstructs a joint.• Bone marrow transplant involves I.V. administration ofmarrow aspirated from the donor’s bones to a recipient.• In chemonucleolysis, a drug is injected into a herniat-ed disk that dissolves the nucleus pulposus, the pulpy,semifluid center of the disk.• Costectomy is the surgical excision of a rib.• Diskectomy is the excision of an intervertebral disk.• In hip replacement, a diseased hip joint is replacedwith a prosthesis (artificial substitute for a missing bodypart).• Laminectomy is the surgical excision of the lamina.• Laminotomy is the transection of a vertebral lamina.• Ostectomy is the excision of a bone or part of a bone.• Osteotomy is an incision or transection of a bone.• A sternotomy is a cut made through the sternum.

64SKELETAL SYSTEM

Let’s reducethat reduction

In the real world, youmay hear people refer toopen reduction with in-ternal fixation as an“ORIF.”

The realworld

Spondylo- comes from the Greek word spondylos, which meansvertebra; syndesis is the Greek word that means binding togeth-er. Therefore, spondylosyndesis is the binding together of thespine, or spinal fusion.


Spelling out spondylosyndesis

845503.qxd 8/19/08 4:35 PM Page 64


Across

2. Bone’s membrane7. Another name for a joint11. Dense connective tissue12. Collarbones13. Color of marrow that makesblood cells

14. Ends of a long bone16. Mineral found in bones17. Bag of synovial fluid18. Rigid dressing on an extremity

Down

1. Degenerative joint disease3. Immature bone cells4. Fingers and toes5. Jaw bone6. Main shaft of a long bone

8. Bone cavity9. Upper leg bone10. Two bones at top of the head15. Immovable joints


Vocabulary builders

At a crossroadsCompleting this crossword puzzle will help you bone up on yourmedical vocabulary. Good Luck!

1 2 3

4 5 6

7

8

9 10

11

12

13

14 15

16

17

18

845503.qxd 8/19/08 4:35 PM Page 65

66SKELETAL SYSTEM

Finish lineThe root osteo-, meaning bone, forms many words related to bone disorders anddiseases. Complete the sentences below by filling in each blank with the appropriateword that begins with osteo-.

1. Osteo______________ is a disorder in which bone mass is reduced.

2. A generalized infection of the bone marrow is called osteo______________.

3. A term used to describe the cutting of a bone is osteo______________.

4. A cell that destroys bone tissue is an osteo________________.

5. Osteo____________ is a common tumor that causes spurs at the end of long bones.

Match gameMatch each of the musculoskeletal system terms below with its definition.

Terms

1. Sternum

2. Tibia

3. Hematopoiesis

4. Coccyx

5. Epiphyses

6. Humerus

7. Femur

8. Osteochondritis

9. Phalanges

10. Mandible

Definitions

A. Production of red blood cells in the bonemarrow

B. Jaw bone

C. Tailbone

D. Flat, sword-shaped bone that’s attached tothe collarbones

E. Upper arm bone

F. Finger or toe bones

G. The largest and strongest of the lower legbones

H. The longest and heaviest bone in the body

I. Bulbous ends of long bones that provide alarge surface for muscle attachment and givestability to joints

J. Inflammation of bone and cartilage


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1. ____ ____ ____ ____ ____ ____ ____

2. ____ ____ ____ ____ ____ ____

3. ____ ____ ____ ____ ____ ____

4. ____ ____ ____ ____ ____ ____ ____

5. ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____

6. ____ ____ ____ ____ ____ ____ ____ ____ ____ ____

1. This is the suture that connects the frontal bone with the parietal bones.2. This is the cartilage that attaches the sternum to the ribs.3. This is what the lower arm bone on the thumb side is called.4. This is the type of joint in the wrists and ankles.5. This is the term for displacement of a bone from its normal position.6. This is the term for joint swelling.


Our bones really

move freely in this

joint. What makes

this possible?

845503.qxd 8/19/08 4:35 PM Page 67

68SKELETAL SYSTEM

1. Porosis; 2. Myelitis; 3. Tomy; 4. Clast; 5. Chondroma

Finish line

1. D; 2. G; 3. A; 4. C; 5. I; 6. E; 7. H; 8. J; 9. F; 10. B

Match game

1. Coronal; 2. Costal; 3. Radius; 4. Gliding; 5. Dislocation; 6. ArthredemaAnswer to puzzle—Diarthrosis

Talking in circles

At a crossroads

Answers

1O

2P E R I

3O S T E U M

4P

5M S S

6D

H7A R T I C U L A T I O N I

A N E E8M A

L D O9F O

10P E P

11C A R T I L A G E B A D H

N B R M L R U Y

G L T U12C L A V I C L E S

13R E D E H R S E L I

S R T T A S14E P I P H Y

15S E S A R

T U L Y16C A L C I U M T

S17B U R S A

R

E18C A S T

845503.qxd 8/19/08 4:35 PM Page 68

Muscle structure and function

A key to learning terminology related to the muscularsystem is knowing the medical prefix for muscle, my(o)-,from the Greek word for muscle, mys. Combined withother words, this prefix forms such terms as myology(the study of muscles), myocardium (heart muscle), andmyositis (inflammation of voluntary muscle tissues).(See A close look at myocardium and Pronouncing keymuscular system terms, page 70.)

More than just heavy liftingMuscles have three functions:

They support the body.

They permit movement.

They produce body heat.

They’re also an integral part of internal organs, suchas the heart, lungs, uterus, and intestines.

4

Health assessmentMuscular system

Just the facts


♦ terminology related to the structure and function ofthe muscular system

♦ terminology needed for physical examination of themuscular system

♦ tests that help diagnose muscular disorders

♦ disorders of the muscular system and theirtreatments.

A close look atmyocardium

The Greek word for mus-cle is myos, and cardiac

is the Greek word forheart. Therefore, myo-

cardium means heartmuscle.


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Tissue issueThe three major types of muscle in the human body areclassified by the tissue they contain:• Skeletal muscles are voluntary (controlled by will)muscles that attach to the skeleton and consist of stri-ated (in thin bands) tissue. They move body parts andthe body as a whole, maintain posture, and implementvoluntary and reflex movements. Skeletal muscles alsogenerate body heat. (See A close look at skeletal mus-cles.)• Visceral muscles are involuntary (not controlled bywill) muscles that contain smooth-muscle tissue. They’refound in such organs as the stomach and intestines. (SeeGut reaction.)

70MUSCULAR SYSTEM

Below is a list of key terms, along with the correct way to pronounce them.


Pronouncing key muscular system terms

Gut reaction

The word visceral is de-rived from the Latin wordviscera, meaning inter-nal organs. Visceral alsomeans intensely emo-tional or instinctive.Think of a “gut reaction.”


Aspartate aminotransferase

Buccinator

Creatine kinase

Dystonia

Epimysium

Fasciorrhaphy

Gastrocnemius

Leiomyosarcoma

Myasthenia gravis

Myokinesimeter

Myositis purulenta

Sarcolemma

Torticollis

Trapezius

AHS-PAR-TAYT AH-MEE-NOH-TRANS-FUHR-RAYS

BUHK-SUH-NAY-TUHR

KREE-UH-TEEN KEYE-NAYS

DIS-TOH-NEE-UH

EP-UH-MISS-EE-UHM

FASH-EE-OR -EH-FEE

GAS-TROK-NEE-MEE-UHS

LEYE-OH-MEYE-OH-SAR-KOH-MUH

MEYE-AHS-THEE-NEE-UH GRAH-VUHS

MEYE-OH-KIN-UH-SIM-UH-TER

MEYE-OH-SEYE-TIS PER-UH-LENT-UH

SAR-KOH-LEM-UH

TOR-TUH-KOL-LIS

TRAH-PEE-ZEE-UHS

Our bodies have

about 600

muscles—not all of

them are as easy to

identify as my biceps

brachii!

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71MUSCLE STRUCTURE AND FUNCTION

Each muscle is classified by the movement it permits. For example, flexors permit the bending of joints, or flexion; abductors permitshortening so that joints can be straightened, or abducted. The illustrations below show some of the body’s major muscles.


A close look at skeletal muscles

Anterior view Posterior view

Facial muscles

Sternocleidomastoid

Deltoid

Pectoralis major(PEK-TOH-RAY-LIS)

Biceps brachii

Serratus anterior(SER-RAY-TUHS)

Brachioradialis

Rectus abdominis

External oblique

Rectus femoris

Vastus lateralis

Sartorius(SAHR-TOR-EE-UHS)

Tibialis anterior(TIB-EE-AY-LIS)

Occipitalis(OK-SIP-I-TAY-LIS)

Trapezius

Deltoid

Triceps brachii(BRAY-KEE-EYE)

Latissimus dorsi(LAH-TIS-I-MUHS)

Gluteus maximus(GLOO-TEE-UHS)

Biceps femoris(FEM-OR-IS)

Gastrocnemius

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• Cardiac muscle is made up of involuntary, striated tis-sue. It’s controlled by the autonomic nervous system andspecialized neuromuscular (meaning both nerve andmuscle) tissue located within the right atrium.

The muscles’ makeupMuscle tissue cells perform specialized activities andvary greatly in size and length. Because they’re usuallylong and slender with a threadlike shape, muscle cells arecalled fibers.

Connective tissue holds muscle fibers together. Bun-dles of muscle fibers are enclosed by a fibrous membranesheath called fascia.

Although muscle cells have the same parts as othercells, several of their structures have special names. Amuscle fiber’s plasma membrane is called a sarcolemmaand its cytoplasm is called sarcoplasm. (See Origins ofsarcolemma and sarcoplasm.)

The ties that bind usTendons are bands of fibrous connective tissuethat attach muscles to the periosteum, a fibrousmembrane that covers the bone. Tendons enablebones to move when skeletal muscles contract, cre-ating energy through the release of the enzymeadenosine triphosphate from the cells.

Ligaments are dense, strong, flexible bands offibrous connective tissue that bind bones to otherbones. Ligaments in the skeletal muscle system con-nect the articular (relating to a joint) ends ofbones. They provide stability and can either limit orfacilitate movement. Deeper inside the body, liga-ments support the organs.

72MUSCULAR SYSTEM

The word

ligament comes

from the Latin

ligare, which means

to tie or bind—and

that is exactly

what ligaments do

to your bones.

A muscle fiber’s plasma membrane is called a sarcolemma, andits cytoplasm is called sarcoplasm. In Latin, sarco means flesh.Both sarcolemma and sarcoplasm share this Latin root.


Origins of sarcolemma andsarcoplasm

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Most skeletal muscles are attached to bones eitherdirectly or indirectly. In a direct attachment, the epi-mysium (fibrous sheath around a muscle) of the musclefuses to the periosteum of the bone. In an indirect at-tachment, the fascia extends past the muscle as a tendonor aponeurosis (deeply set fascia), which in turn attach-es to the bone. In the human body, indirect attachmentsoutnumber direct attachments.

Putting it in motionMuscles depend on one an-other for movement; amuscle rarely acts on itsown. Prime movers aremuscles that actively pro-duce a movement. Antag-onists are muscles thatoppose the prime moversand relax as the prime movers contract. Synergists con-tract along with the prime movers and help execute themovement or provide stability.

During contraction, one of the bones to which themuscle is attached stays stationary while the other ispulled in the opposite direction. The point where themuscle attaches to the sta-tionary bone is called theorigin; the point where itattaches to the more move-able bone, the insertion.The origin usually lies onthe proximal (nearest to)end of the bone; the inser-tion, on the distal (farthestaway) end.

Key musclesThe name of a skeletal muscle may come from its loca-tion, action, size, shape, attachment points, number of di-visions, or direction of fibers. (See Muscle structure,page 74.)


Remember: An

antagonist is one

who opposes

another…

…and synergymeans working

together.

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Scalp musclesThe top of the head contains no muscles but has a broad,flat tendon called the epicranial aponeurosis that con-nects to three nearby muscle groups. (See Dissecting epi-cranial aponeurosis.)

74MUSCULAR SYSTEM

Each muscle contains cell groups called muscle fibers that extend the length of the muscle. A sheath of connective tissues—called the perimysium—binds the fibers into a bundle, or fasciculus.

A strong sheath

A stronger sheath, the epimysium, binds the fasciculi together to form the fleshy part of the muscle. Beyond the muscle, theepimysium becomes a tendon.

Fine fibers

Each muscle fiber is surrounded by a plasma membrane called the sarcolemma. Within the sarcoplasm (or cytoplasm) of themuscle fiber lie tiny myofibrils. Arranged lengthwise, myofibrils contain still finer fibers, called thick fibers and thin fibers.


Muscle structure

Perimysium(PER-I-MIS-EE-UHM)

EpimysiumBone

Tendon

Myosin(MEYE-OH-SIN)Actin

Myofibril(MEYE-OH-FEYE-BRIL)

Sarcoplasm(SAR-KOH-PLAZM)

Sarcolemma

Nuclei

Endomysium(EN-DOH-MIS-EE-UHM)

Motor neuron

Nerve endingFasciculus(FAS-SIK-YOU-LUHS)

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• The occipitofrontal group houses both the occipi-talis muscle, which pulls the scalp backward, and thefrontalis muscle, which pulls it forward. Raising the eye-brows and wrinkling the forehead use the frontalis mus-cle.• The temporoparietal group includes the temporalismuscle, which tightens the scalp and moves the earsforward.• The auricular group contains three muscles (the an-terior, superior, and posterior), which move the earforward, upward, and backward.

Facial musclesFacial expressions, such as a smile, frown, or look of sur-prise, depend on specialized muscles.

Smile later, buccinatorThe buccinator muscle, also called the trumpetermuscle, compresses the cheeks for smiling or blowing(bucca means cheek in Latin). The corrugator super-cilii draws the eyebrows together in a frown (corruga-tus means wrinkled, as in a corrugated box). When theeyes widen in surprise, the orbicularis oculi (orbitmeans around and ocul means eye) moves the eyelids.

Chew on thisThe masseters are the chewing muscles (masticatemeans chew), and the pterygoids open and close themouth. The prefix pteryx- means wing and describesthe shape of these muscles. (See Saying pterygoid isn’tp-terribly difficult, page 76.)

Neck and shoulder musclesSternocleidomastoid muscles are paired muscles oneither side of the neck that allow the head to move. Thisname combines the muscles’ origins in the sternum andclavicle with their insertion point in the mastoidprocess of the temporal bone.

No shrugging it offThe trapezius muscle on the back of the neck raises andlowers (shrugging) the shoulders. Arms can be crossed


Dissectingepicranialaponeurosis

Epicranial aponeurosis

looks intimidating untilyou break it down. InGreek, epi means upon,kranion means skull, apo

means away, and neu-

ron means tendon. Epi-cranial aponeurosis is afibrous membrane thatcovers the cranium, orskull, between the occip-ital and frontal musclesof the scalp.


Arrgh! When you

see my cheeks (or

buccae, in Latin) go

up in a smile, you know

I’m using my

buccinator muscles!

845504.qxd 8/19/08 4:44 PM Page 75

when the pectoralis major muscle adducts and flexesthe upper arm.

Thorax musclesThe diaphragm, a dome-shaped muscle located in thechest, flattens during inspiration to increase the size andvolume of the thoracic cavity. This allows air to enterthe lungs.

Now for a little ribbingThe external intercostal (costa means rib in Latin)muscles lift the ribs during breathing, and the internalintercostals lower them. The use of these muscles ismost noticeable when a person is out of breath.

Abdominal musclesMuscles in the abdominal cavity form three layers, theexternal oblique (the outermost), the internaloblique (the middle), and the transversus abdomi-nus (the innermost), with fibers running in differentdirections.

A muscular girdleThe three layers form a strong “girdle” of muscle thatprotects and supports the internal organs. These musclescontract during childbirth, defecation, coughing, andsneezing. The rectus abdominis muscle runs down the

76MUSCULAR SYSTEM

The diaphragm

flattens during

inspiration to

increase the size

and volume of the

thoracic cavity.

English doesn’t have a sound for the consonant cluster pt at thebeginning of a word. Pterygoid is derived from the Greek wordfor wing, pteryx. When pt is pronounced in English, the p issimply silent, as it is when you say the name of the “winged”dinosaur, the pterodactyl. Therefore, pterygoid is pronouncedTEHR-IH-GOYD.


Saying pterygoid isn’t p-terriblydifficult

845504.qxd 8/19/08 4:44 PM Page 76

midline of the abdomen and helps flex the spinal columnas well as support the abdomen.

Arm and hand musclesSeveral important muscles contribute to the movement ofthe arms and hands:• triceps brachii, which extends the lower arm• brachialis, which flexes the lower arm• biceps brachii, which flexes the lower arm andsupinates (turns upward) it along with the hand• pronator teres, which flexes and pronates (rotatesthe forearm so that the palm of the hand faces down-ward) the lower arm.

It’s all in the wristMany small muscles work together to flex and extend thewrists, hands, and fingers. Here are a few examples:• Flexor muscles bend the fingers.• Lumbrical muscles allow fine movements of thehands.• The flexor carpiradalis and the flexor carpiulnarisboth flex and adduct the wrist joints.

Pelvic floor musclesA muscular “floor” called the perineum supports thepelvic organs and protects the diamond-shaped pelvicopening. The perineum occupies the space between theanus and vagina in females and the anus and scrotum inmales.

The levator ani muscle and the ischiococcygeusand sacrococcygeus muscles support the pelvic organsand assist with childbirth and defecation. (See How do Isay coccygeus?, page 78.) The sphincter ani musclekeeps the anus closed.

Thigh and upper leg musclesThree groups of muscles affect movement in the thighand upper leg area.

The first group includes those that cross the front ofthe hip:• The internal obturator laterally rotates the thigh andextends and abducts the thigh when it’s flexed.


The prefix brachi-

comes from the Latin

word that means arm,

brachium, from which

we also get the word

embrace!

845504.qxd 8/19/08 4:44 PM Page 77

• The external obturator, along withboth the superior and inferior gemellus,laterally rotates the thigh as well.• The piriformis laterally abducts, ro-tates, and extends the thigh.• The quadratus femoris flexes and ex-tends the leg in addition to laterally rotat-ing the thigh.

Bringing up the rearThe second group consists of the gluteals(from the Greek word gloutos, whichmeans buttocks). The gluteus minimusand medius abduct and rotate the thighwhile the gluteus maximus extends and rotates thethigh.

Adduction is the functionThe third group, the adductors, includes the powerfullongus, brevis, and magnus muscles, which draw backthe thigh after abduction. The gracilis flexes and adductsthe leg and also adducts the thigh.

Lower leg musclesTwo groups of muscles move the lower leg. The first, thequadriceps femoris, includes the vastus lateralis, me-dialis, and intermedius—all of which work to extendthe leg—and the rectus femoris, which flexes the thighand extends the leg. (See Quads.)

The second group of muscles passes behind thethigh, and their tendons form the hamstrings, fromwhich the group takes its name. The semimembranosus

78MUSCULAR SYSTEM

The quadratus

femoris flexes and

extends the leg, in

addition to laterally

rotating the thigh.

Coccygeus is pronounced COCK-SIHJ-EE-UHS. It’s derived fromcoccyx, the Greek name for the cuckoo, whose bill was thoughtto have a similar shape to the small bone (henceforth termed thecoccyx) at the base of the spinal cord in the human body.


How do I say coccygeus?

845504.qxd 8/19/08 4:44 PM Page 78

and semitendinosus extend thethigh, and the biceps femoris helpsto both extend the thigh and flex theleg.

Tailor madeOther lower leg muscles include thegastrocnemius and the sartorius.The gastrocnemius flexes the leg andextends the foot. It’s commonlycalled the calf muscle (the Achillestendon attaches to this muscle). Thesartorius flexes and adducts the leginto the “tailor” position.

Foot musclesExtrinsic foot muscles are located in the leg but pull ontendons that move bones in the ankle and foot. Thesemuscles allow dorsiflexion (upward turning of the footor toes), plantar flexion (movement toward the toes),inversion (turning inward movement), and eversion(turning outward movement) of the foot.

Intrinsic foot muscles are located within the footand produce flexion, extension, abduction, and adduc-tion of the toes. The most important muscles of the footinclude:• soleus, which extends and rotates the foot (the Latinword for sun is sol; just as the sun causes the earth to ro-tate, this muscle causes the foot to rotate)• tibialis anterior, which elevates and flexes the foot


While working out in the gym, you often hear the word quads ap-plied to the thigh muscles as a whole. In medical terminology, it’simportant to know the four muscles that make up the quadriceps

femoris—the rectus femoris, vastus lateralis, vastus medialis,

and vastus intermedius.

The real world

Quads

The sartoriusmuscle gets its

name from the

Latin word sartor,

which means tailor.

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• tibialis posterior, which extends the foot and turns itinward• peroneus longus, which extends and abducts the footand turns it outward• peroneus brevis, which extends and abducts the foot• peroneus tertius, which flexes the foot and turns itoutward.


When a patient seeks medical help for a muscular prob-lem, it’s usually because of a physical mishap or a chronicache.

Common complaintsThe term myopathy refers to any disease of the skeletalmuscles. Below are other terms you may need to knowwhen examining a patient with a myopathic condition orother muscular complaints:• Myalgia is muscle pain or tenderness. For instance, anathlete with a patient with a sore pitching shoulder mighthave myalgia.• Myoclonus is a spasm of a muscle.• Myotasis is a continual stretching of a muscle, com-monly referred to as a pulled muscle.• Myotonia is chronic muscle contraction or irritability.Myotonia may be confirmed if there’s isometric contrac-tion—the muscle length remains the same as the tensionon it increases.• Tenalgia is a pain in the tendon, such as tennis elbow.• Tetany is hyperexcitability of nerves and muscles,which results from lessened concentration of extracellu-lar ionized calcium.• A tic is a small muscle spasm.

Common observationsBelow are some terms that are useful while performing aphysical examination:• Myelomalacia is muscle softening, which may indicatemyoatrophy (muscle wasting) or myonecrosis (death ofmuscle tissue fibers).• Myosclerosis is muscle hardening.

80MUSCULAR SYSTEM

Memoryjogger

The acronymTIPS will

keep you on your toesand help you remem-ber the muscles ofthe foot:

TIbialis anterior andposterior

Peroneus longus, bre-vis, and tertius

Soleus.

The suffix -algia

comes from the Greek

and means pain. So

tenalgia means pain

in the tendon. I could

tell you that!

845504.qxd 8/19/08 4:44 PM Page 80

Action reaction• Myobradia is the term used to describe the slow reac-tion of a muscle to prodding. It may be caused by tissuewasting or death.• Myospasm is the term used to describe muscle convul-sions that occur with prodding. It may signal an inflam-mation of the voluntary muscle tissue, or myositis.

Diagnostic tests

Three types of samples—blood, urine, and tissue—maybe taken to diagnose muscle disorders. Scanners andother equipment are commonly necessary as well. Beloware some of the terms, tests, and tools that may be used.

Physical testsThree tests are commonly used to assess a patient forcarpal tunnel syndrome.

Tingle is the signalTinel’s sign—a tingling over the median nerve on lightpercussion—is seen in cases of carpal tunnel syndrome.

Flex testPhalen’s maneuver is used to reproduce the symptomsof carpal tunnel syndrome. In this test, the patient ex-tends his forearms horizontally while completely flex-ing the wrists for 1 minute. If the patient experiencestingling, numbness, or pain, carpal tunnel syndromemay be present.

Compression impressionA compression test can be used tosupport a diagnosis of carpal tunnelsyndrome. A blood pressure cuff isplaced on the forearm and inflated above the patient’ssystolic blood pressure for 1 to 2 minutes. If carpal tunnelsyndrome is present, this intervention produces paresthe-sia along the distribution of the median nerve.

81DIAGNOSTIC TESTS

If Phalen’s

maneuver

produces pain,

carpal tunnel

syndrome is

present.

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Blood testsEnzyme levels or the presence of acids in the blood-stream can help diagnose muscular disease. Blood testsare named after the enzyme or acid they’re designed todetect:• Elevated levels of alanine aminotransferase, a skele-tal enzyme, may indicate muscle tissue damage.• Elevated levels of aspartate aminotransferase, an-other skeletal muscle enzyme, may indicate muscle dam-age from muscle trauma or muscular dystrophy.• Creatine kinase, an isoenzyme found in both skeletaland cardiac muscle, may indicate damage from muscletrauma, I.M. injections, myocardial infarction, or muscu-lar dystrophy.

Urine testsA myoglobin urine test is used to detect the presence ofmyoglobin in urine. Myoglobin is normally found in theheart and skeletal muscle and, when found in the urine,indicates extensive muscle damage.

Muscle biopsyIn muscle biopsy, a needle or incision biopsy is used toextract a specimen of muscle tissue for examination. Thismicroscopic evaluation of muscle tissue samples is com-monly required for an accurate diagnosis of muscular dis-orders.

Tools of the tradeAn accurate “image” of the myopathy, which is possiblewith the use of various types of equipment, may aid in di-agnosis.

The equipmentIn computed tomography scanning, multiple X-raybeams pass through the body at different angles, strikingradiation detectors that produce electrical impulses. Acomputer converts the impulses into digital informationthat detects tumors in muscle tissue. (See CAT scan.)

82MUSCULAR SYSTEM

The presence of

myoglobin in a

urine sample

indicates extensive

muscle damage.

CAT scan

The computed tomogra-

phy scan was originallyknown as the computer-

ized axial tomography

scan. That’s why in prac-tice you’ll still hear thistest referred to as aCAT scan.

The realworld

845504.qxd 8/19/08 4:44 PM Page 82

An electromyogram records the electrical activityof skeletal muscles through surface or needle electrodes.It’s used to diagnose neuromuscular disorders and pin-point motor nerve lesions.

In magnetic resonance imaging, a powerful mag-netic field and radiofrequency energy are used to pro-duce images based on the hydrogen content of body tis-sues. Also called nuclear magnetic resonance, it’s usedto diagnose muscle disease.

A myokinesimeter measures the muscular contrac-tions that result from stimulating the muscles with elec-trical current.

Disorders

A wide range of factors, including trauma, heredity, au-toimmunity, and the normal aging process, can lead tomuscle disorders. This section covers terms associatedwith muscular disorders.

Muscle conditionsBelow are terms for common muscle conditions:• Atrophy is the wasting of muscle.• Contractures, the abnormal flexion and fixation ofjoints, are typically caused by muscle atrophy and may bepermanent.• Footdrop is the inability to maintain the foot in a nor-mal, flexed position (dragging of the foot). This complica-tion is commonly associated with trauma or paralysis.• A shin splint is a strain of the long flexor muscle ofthe toes that’s caused by strenuous athletic activity.• Spastic paralysis is the involuntary contraction of amuscle with an associated loss of function.• A sprain is a complete or incomplete tear in the sup-porting ligaments surrounding a joint.• A strain is an injury to a muscle or tendinous attach-ment.

83DISORDERS

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Tumors and lesionsBelow are terms for muscle tumors and lesions:• A fibroid tumor, or leiomyoma, is a benign (non-cancerous) tumor found in smooth muscle. It’s mostcommon in the uterus.• A leiomyosarcoma is a malignant tumor of smoothmuscle that’s usually found in the uterus.• A myoblastoma is a benign lesion of soft tissue.• A myofibroma is a benign tumor containing muscularand fibrous tissue.• A myosarcoma is a malignant tumor derived frommuscle tissue.• A rhabdomyoma is a benign tumor of striated muscle.• A rhabdomyosarcoma is a highly malignant tumorthat originates from striated muscle cells.

Infection and inflammationListed here are terms for muscular infection and inflam-mation:• Bursitis is a painful inflammation of one or more ofthe bursae, closed sacs that cushion muscles and ten-dons over bony prominences such as the knee.• Dermatomyositis is a connective tissue disease that’smarked by itching and skin inflammation in addition totenderness and weakness of muscles.• Epicondylitis, also known as tennis elbow, is an in-flammation of tendons in the forearm at their attachmentto the humerus.• Fasciitis is inflammation of the fasciae.• Myocellulitis is inflammation of the cellular tissuewithin a muscle.• Myofibrosis is an overgrowth of fibrous tissue that re-places muscle tissue.• Myositis purulenta is any bacterial infection of themuscle tissue that may result in pus formation and, ulti-mately, gangrene.• Tendinitis, a painful inflammation of tendons andtheir muscle attachments to bone, is commonly causedby trauma, congenital defects, or rheumatic diseases.(See Understanding the suffix -itis.)

84MUSCULAR SYSTEM

Epicondylitis

anyone?

845504.qxd 8/19/08 4:44 PM Page 84

Syndromes and diseasesBelow are terms for muscular syndromes and dis-eases:• An Achilles tendon contracture is a shorten-ing of the Achilles tendon. It can cause pain and re-duced dorsiflexion.• Carpal tunnel syndrome is a painful disorderof the wrist and hand that results from rapid, repet-itive flexion and extension of the wrist.• Dupuytren’s contracture is a progressive, pain-less contracture of the palmar fasciae. It causes thelast two fingers to contract toward the palm. (SeeDupuytren’s contracture, page 86.)• Fibromyalgia syndrome, the cause of which is un-known, is a chronic disorder that produces pain in themuscles, bones, or joints.• Muscular dystrophy is a group of degenerative genet-ic diseases characterized by weakness and progressiveatrophy of skeletal muscles, with no evidence of involve-ment of the nervous system.• Myasthenia gravis is an abnormal weakness andfatigability, especially in the muscles of the throat andface. It results from a defect in the conduction of nerveimpulses at the myoneural junction.• Torticollis is a neck deformity in which the neck mus-cles are spastic and shortened, causing the head to bendtoward the affected side and the chin to rotate towardthe unaffected side.

85DISORDERS

People who do

a lot of typing

commonly suffer

from carpal

tunnel syndrome.

The suffix -itis is derived from Greek and means the inflammationof. Anyone who has suffered the burning pain of tendinitis (inflam-mation of the tendons and their attachments to the bone) can con-firm the accuracy of this suffix.


Understanding the suffix -itis

845504.qxd 8/19/08 4:44 PM Page 85

Treatments

Rest is commonly all that’s needed to treat muscle condi-tions. Other common options include immobilizing themuscle with a sling (a bandage that supports an injuredbody part), splint (an orthopedic appliance that immobi-lizes and supports an injured body part), or cast (a rigiddressing that’s placed around an extremity); undergoingphysical therapy; applying cold or hot compresses (wetor dry cloths); and medicating with prescription drugs.

Douse the flameDrug therapy includes nonsteroidal anti-inflammatorydrugs to decrease inflammation, muscle relaxants tocombat spasticity and relax muscles, and corticosteroidsto combat inflammation.

Drain the painWhen inflammation is the problem, as in such conditionsas tendinitis and bursitis, fluid is sometimes removedfrom the joint with a hollow needle. The term for thisprocedure is aspiration.

Free at lastWhen a muscle compresses a nerve, as in carpal tunnelsyndrome, surgery may be required if more conservativetreatments fail. In carpal tunnel syndrome, neurolysis,the freeing of the nerve fibers, is used to remove the en-tire carpal tunnel ligament so there’s more space for themedian nerve to pass through the carpal tunnel.

Heat waveShort-wave diathermy, in which a current is used togenerate heat within the muscle, is used to control painand decrease muscle spasm.

Rub-outMassage is the methodical use of manipulation, pres-sure, friction, and kneading to promote circulation, re-lieve pain, and reduce tension. Massage is used for pa-tients who have restricted movement.

86MUSCULAR SYSTEM

Dupuytren’scontracture

Guillaume Dupuytren(DOO-PWEE-TRAH)(1777-1835) was a Frenchsurgeon and clinicalteacher. He became in-trigued by a peculiarform of contracture (thepermanent contractionof a muscle) that causedthe fingers to curl in thehand. After dissection,he discovered the prob-lem was centered in thepalmar fasciae.


845504.qxd 8/19/08 4:44 PM Page 86


Across

3. Floor of the pelvis7. Fibrous membrane sheath8. Critical for breathing

10. A muscle twitch12. Muscles composed of thinbands

Down

1. Inflamed bursae2. Responsible for attaching bonesto each other4. Muscle pain or tenderness5. Muscle cell groups6. Adjective for heart muscles

9. Attaches muscles to theperiosteum11. Reduction in the size ofmuscles


If you’ve got

any muscles

left over, pass

’em along.

Vocabulary builders

At a crossroadsHere’s a little crossword puzzle to help pump up your mentalmuscle. Good luck!

1 2

3 4

5

6 7

8 9

10 11

12

845504.qxd 8/19/08 4:44 PM Page 87


88MUSCULAR SYSTEM

Finish lineThe suffix -itis comes from the Greek and means the inflammation of. Fill in the blanksbelow to form the correct muscle disorder.

1. Painful inflammation of tendons is called ______________ itis.

2. Painful inflammation of one or more bursae is called ______________ itis.

3. Inflammation of the fasciae is called ______________ itis.

4. Inflammation of cellular tissue within a muscle is called ______________ itis.

5. Inflammation of connective tissue and weakness of muscle is called______________ itis.


1.

2.

3.

4.

845504.qxd 8/19/08 4:44 PM Page 88


Talking in circlesUse the clues below to fill in the blanks with the appropriate word. Then unscramblethe circled letters to find the answer to the question posed below.

1. ____ ____ ____ ____ ____ ____ ____ ____ ____

2. ____ ____ ____ ____ ____ ____ ____ ____ ____

3. ____ ____ ____ ____ ____ ____ ____ ____ ____

4. ____ ____ ____ ____ ____ ____ ____ ____ ____ ____

5. ____ ____ ____ ____ ____ ____ ____ ____ ____

6. ____ ____ ____ ____ ____ ____

1. The point where a muscle attaches to a more moveable bone2. The muscle that creates horizontal wrinkles on the forehead3. The group of muscles that wiggle the ears4. The muscle that flexes the lower arm5. The muscle that allows the leg to cross in the tailor position6. A paroxysmal muscle spasm


Playing in the sun is

reminding me of the

muscle that makes

the foot rotate. Do

you know which

muscle I mean?

845504.qxd 8/19/08 4:44 PM Page 89

90MUSCULAR SYSTEM

1. Tendin; 2. Burs; 3. Fasci; 4. Myocellul; 5. Dermatomyos

Finish line

1. Trapezius; 2. Gastrocnemius; 3. Buccinator; 4. Leiomyosarcoma

O see, can you say?

1. Insertion; 2. Frontalis; 3. Auricular;4. Brachialis; 5. Sartorius; 6. Tetany

Answer to puzzle—Soleus

Talking in circles

At a crossroads

Answers

Let’s mosey on

out of the

muscular system

and into the

integumentary

system!

1B

2L

U3P E R I N E U

4M

R G Y5F

S6C A

7F A S C I A

8D I A P H R A G M

9T L B

T R E E G E10T I C

11A D N N I R

S12S T R I A T E D A S

R A S O

O C N

P S

H

Y

845504.qxd 8/19/08 4:44 PM Page 90

Skin structure and function

The largest body system, the integumentary system in-cludes the skin, or integument (from the Latin wordintegumentum, which means covering), and its ap-pendages—hair, nails, and certain glands. It covers anarea that measures 103⁄4 to 211⁄2 ft2 and accounts forabout 15% of body weight. (See Pronouncing key integu-mentary system terms, page 92.)

Skin layersTwo distinct layers of skin, the epidermis and dermis,lie above a third layer of subcutaneous fat.

On the face of itThe outermost layer, the epidermis, varies inthickness from less than 0.1 mm on the eyelids tomore than 1 mm on the palms and soles. It’s com-posed of avascular (without a direct blood supply),

5

Health assessmentIntegumentary system

Just the facts


♦ terminology related to the structure and function ofthe integumentary system

♦ terminology needed for physical examination of theintegumentary system

♦ tests that help diagnose disorders of the integu-mentary system

♦ disorders of the integumentary system and theirtreatments.

Dermatology, the

study of skin, comes

from the Greek words

derma, which means

skin, and logos, which

means science.

845505.qxd 8/19/08 4:54 PM Page 91

squamous tissue that’s stratified (arranged in multiplelayers). (See Squamous tissue revealed.)

The stratum corneum, the outermost part of theepidermis, consists of cellular membranes and keratin, aprotein. Langerhans’ cells are interspersed among thekeratinized cells below the stratum corneum. Epidermalcells are usually shed from the surface as epidermaldust.

Stratum basale, also called the basal or base lay-er, produces new cells to replace superficial keratinizedcells that are continuously shed or worn away. It alsocontains specialized skin cells called melanocytes thatprotect the skin by producing and dispersing melanin tosurrounding epithelial cells. Melanin is a brown pigment

92INTEGUMENTARY SYSTEM

Below is a list of key terms, along with the correct way to pro-nounce them.


Pronouncing key integumentarysystem terms

Aphthous stomatitis

Ecchymosis

Eczema

Erythema

Onychomycosis

Petechia

Phthirus pubis

Rosacea

Sebaceous

Subcutaneous

Telangiectasis

Verrucae

Vitiligo

AF-THUHS STOH-MUH-TEYE-TIS

EK-EE-MO-SIS

EK-ZEH-MUH

ER-EH-THEE-MUH

ON-EH-KOH-MEYE-KOH-SIS

PEH-TEE-KEE-UH

THEYE-RUHS PYOU-BIS

ROH-ZAY-SHEE-UH

SEE-BAY-SHUHS

SUHB-KYOU-TAY-NEE-UHS

TEL-AN-JEE-EK-TAY-SIS

VEH-ROO-KEE

VIT-IH-LEYE-GOH

The word

stratumcomes from the

Latin sternere,

which means to

spread out.

845505.qxd 8/19/08 4:54 PM Page 92

that helps filter ultraviolet light. (See Close-up view ofthe skin.)

Digging beneath the surfaceThe skin’s second layer, the dermis, also called the cori-um, is an elastic system that contains and supports bloodvessels, lymphatic vessels, nerves, and epidermal ap-pendages.

Most of the dermis is made up of extracellular mater-ial called matrix. Matrix contains connective tissuefibers, including collagen, a protein that gives strengthto the dermis; elastin, which makes the skin pliable; andreticular fibers, which bind the collagen and elastinfibers together. These fibers are produced by dermalfibroblasts, spindle-shaped connective tissue cells.

93SKIN STRUCTURE AND FUNCTION

The illustration below can help you visualize the major components of the skin.


Close-up view of the skin Squamoustissue revealed

Squamous is derivedfrom the Latin term forthe scale of a fish or ser-pent, squama. It’s used inanatomy to describethin, flat platelike orscalelike structures—inthis case, squamous tis-sue.


Epidermis

Dermis

Subcutaneous tissue

Stratum corneum

Stratum basale(BAY-SAY-LEE)

Papillary dermis

Sebaceous gland

Reticular dermis

Hair follicle

Eccrine sweat gland(EK-RIN)Hair papilla

Nerve

Blood vessel

845505.qxd 8/19/08 4:54 PM Page 93

The dermis has two layers:

The papillary dermis has fingerlike projections(papillae) that nourish epidermal cells. The epidermis liesover these papillae and bulges downward to fill thespaces. A collagenous membrane known as the base-ment membrane separates the epidermis and dermisand holds them together.

The reticular dermis covers a layer of subcuta-neous tissue, the adipose or panniculus adiposus,that’s primarily composed of fat cells. In addition to insu-lating the body, the reticular dermis provides energy andabsorbs mechanical shock. (See Uncovering the pan-niculus adiposus.)

Epidermal appendagesNumerous epidermal appendages occur throughout theskin. They include the hair, nails, sebaceous glands, andtwo types of sweat glands—eccrine and apocrine.

HairHairs are long, slender shafts composed of keratin. At theexpanded lower end of each hair is a bulb or root. On itsundersurface, the root is indented by a hair papilla, acluster of connective tissue and blood vessels.

A hair-raising experienceEach hair lies within an epithelial-lined sheath called ahair follicle. A bundle of smooth-muscle fibers, the ar-


Put the

emphasis on the

p. The papillary

dermis has

projections that

push into and

nourish the

epidermal cells

above it.

The panniculus adiposus is a specialized skin layer that’s pri-marily composed of fat cells. In fact, panniculus is a Latin termthat means a small piece of cloth or covering, or a layer. Adipose

means fat.


Uncovering the panniculusadiposus

845505.qxd 8/19/08 4:54 PM Page 94

rector pili, extends through the dermis and attaches tothe base of the follicle. When these muscles contract, hairstands on end.

NailsSituated over the distal surface of the end of each fingerand toe, nails are specialized types of keratin. The nailplate, surrounded on three sides by the nail folds (orcuticles), lies on the nail bed. The nail plate is formedby the nail matrix, which extends proximally about 1⁄4�(5 mm) beneath the nail fold.

Under the keratin moonThe distal portion of the matrix shows through the nail asa pale crescent-moon-shaped area, called the lunula. Thetranslucent nail plate distal to the lunula exposes the nailbed. The vascular bed imparts the characteristic pinkappearance under the nails. (See Lunar expedition.)

The sebaceous glandsSebaceous glands occur on all parts of the skin exceptthe palms and soles. They are most prominent on thescalp, face, upper torso, and genitalia.

Nature’s conditionerSebaceous glands produce sebum, an oily, lipid sub-stance that helps protect hair and skin. Sebaceous glandssecrete sebum into hair follicles via the sebaceous ducts.Sebum then exits through the hair follicles’ openings toreach the skin’s surface.

The sweat glandsWidely distributed throughout the body, eccrine glandsproduce an odorless, watery fluid with a sodium concen-tration equal to that of plasma. A duct (pore) from thecoiled secretory portion passes through the dermis andepidermis, opening onto the skin surface.

Located chiefly in the axillary and anogenital areas,the apocrine glands have a coiled secretory portion thatlies deeper in the dermis than that of the eccrine glands.Ducts connect the apocrine glands to the upper portionsof the hair follicles.

95SKIN STRUCTURE AND FUNCTION

Lunarexpedition

The lunula gets its namefrom its crescent-moonshape. Luna is the Latinword for moon and thesuffix -ula indicatessmall. Another wordthat shares this root islunacy—literally, moon-sickness.


845505.qxd 8/19/08 4:54 PM Page 95

A puddle under pressureEccrine glands in the palms and soles secrete fluid, main-ly in response to emotional stress. The other three mil-lion eccrine glands respond primarily to thermal stress,effectively regulating temperature.

Apocrine glands begin to function at puberty. Theyhave no known biological function but may be involvedwith sexual olfactory messages. As bacteria decomposethe fluids that these glands produce, body odor occurs.

FunctionThe integumentary system performs many vital functions,including protection of inner body structures, sensoryperception, and regulation of body temperature andblood pressure.

More than just a pretty faceThe top layer of the skin protects the body against trau-matic injury, noxious chemicals, and bacterial and micro-organismal invasion. Langerhans’ cells, specializedcells in this layer, enhance the body’s immune responseby helping process antigens that enter the skin. (See Call-ing Doctor Langerhans.)

Keeping you in touchSensory nerve fibers originate in the nerve roots alongthe spine and terminate in segmental areas of the skinknown as dermatomes. These nerve fibers carry im-pulses from the skin to the central nervous system.

An all-weather coveringAbundant nerves, blood vessels, and eccrine glands with-in the skin’s deeper layer aid thermoregulation, or con-trol of body temperature. When the skin is too cold,blood vessels constrict, leading to a decrease in bloodflow through the skin and conservation of body heat.

When the skin is too hot, small arteries in the secondskin layer dilate, increasing blood flow and reducingbody heat. If this doesn’t adequately lower temperature,the eccrine glands act to increase sweat production, andsubsequent evaporation cools the skin.


Calling DoctorLangerhans

Many medical terms arenamed after the doctorswho first brought atten-tion to them.

Paul Langerhans(1847-1888), a Germandoctor, anatomist, andpathologist, is bestknown for his researchon clusters of pancreaticcells, now known as theislets of Langerhans.

However, he also identi-fied Langerhans’ cells,

which are specializedcells in the skin that helpenhance the body’s im-mune system.


Memoryjogger

To rememberthe func-

tions of the skin,think PPR:

Perception (sensory)

Protection (of thebody)

Regulation (of bodytemperature andblood pressure).

845505.qxd 8/19/08 4:54 PM Page 96

Pressure cookerDermal blood vessels also aid regulation of systemicblood pressure through vasoconstriction.

Other odd jobsWhen stimulated by ultraviolet light, the skin synthesizesvitamin D3 (cholecalciferol). It also excretes sweat throughthe sweat glands. Sweat contains water, electrolytes, urea,and lactic acid.


The skin can provide useful information about the body’soverall condition. Below are terms associated with acomplete skin examination.

Skin colorDecreased hemoglobin level and oxygen in the bloodcause changes in skin color. Skin color also responds tochanges in the quality and amount of blood circulatingthrough superficial blood vessels.

Blue in the faceCyanosis is a bluish skin color that’s caused by an ex-cess of oxygen-starved hemoglobin molecules in theblood. Pale skin is called pallor, and pale, cyanotic skinaround the lips is known as circumoral pallor.

Seeing redEcchymosis is a reddish purple skin discolorationthat’s caused by hemorrhages in the dermal or intra-dermal spaces. Erythema refers to redness or inflam-mation of the skin resulting from congestion of the su-perficial capillaries.

Purpura is purple-red or brown-red discolorationon the skin due to hemorrhage in the tissues. Small(pinpoint) discolored areas are called petechiae,whereas large ones are called ecchymoses.


Cyanosis is

Greek to me no

longer. Cyan-comes from the

Greek word

kuanos, meaning

dark blue.

845505.qxd 8/19/08 4:54 PM Page 97

Feeling yellow—not mellowYellowing of the skin, known as jaundice, is caused byelevated bilirubin levels.

Carotenemia is a yellow-orange skin discolorationthat’s caused by excess levels of carotene in the blood-stream.

Skin turgorTurgor is a condition of normal tension in the skin andreflects the skin’s elasticity.

Keeping its shapeTurgor is assessed by gently grasping and pulling up afold of skin. Normal skin returns to its flat shape within 3seconds. Abnormal (slow) turgor may be a sign of dehy-dration or connective tissue disorders. (See Turgor andits Latin root.)

LesionsAllergens, weather, injury, and various diseases can pro-duce lesions, or abnormal changes in the skin. Types oflesions include wounds, sores, tumors, and rashes.

First signs of troublePrimary lesions are the first lesions of an onsetting dis-ease. Below are examples:• A bulla is a fluid-filled lesion, also called a blister orbleb.• A cyst is a semisolid encapsulated mass that extendsdeep into the dermis.• A macule is a flat, pigmented area that’s less than 3⁄8� indiameter; a freckle is an example of a macule.• A papule is a firm, raised lesion up to 1⁄4� in diameterthat may be the same color as the skin or may be pig-mented.• A plaque is a flat, raised patch on the skin.• A pustule is a lesion that contains pus, which gives it ayellow-white color.• A tumor is an elevated solid lesion larger than 3⁄4� thatextends into the dermal and subcutaneous layers.


Carotene is an

enzyme that’s also

found in carrots.

When a person has

carotenemia, an

excess of carotene in

the bloodstream, he

turns orange like a

carrot.

Turgor and itsLatin root

Turgid and turgor comefrom the Latin wordturgidus, which meansswollen. However, turgor

refers to the normal ten-sion of the skin, or thelack of excessiveswelling.


845505.qxd 8/19/08 4:54 PM Page 98

• A vesicle is a raised, fluid-filled lesion that’s less than1⁄4� in diameter. Chickenpox produces vesicles.• A wheal is a raised, firm lesion with intense, usuallytemporary, swelling around the area. Urticaria, or hives,are a type of wheal.

As if that wasn’t bad enoughA secondary lesion results when changes occur in a pri-mary lesion. Below are examples:• Atrophy is thinning of the skin surface that may becaused by a disorder or aging.• Crust is dried exudate (drainage) covering an erodedor weeping area of skin.• An erosion is a lesion that’s caused by loss of theepidermis.• Excoriation is a linearly scratched or abradedarea.• Fissures are linear cracks in the skin that extendinto the dermal layer. Chapped skin causes fissures.• A keloid is a hypertrophied scar.• Lichenification is characterized by thick, rough-ened skin with exaggerated skin lines.• Scales are thin, dry flakes of shedding skin.• Scars are fibrous tissue caused by trauma, deepinflammation, or a surgical incision.• An ulcer is an epidermal and dermal destructionthat may extend into the subcutaneous tissue.

Diagnostic tests

Many skin conditions are diagnosed on sight, but severalstudies are used to diagnose skin disorders and systemicproblems.

Allergy testingThe patch test identifies allergies to such substances asdust, mold, and foods. During this test, paper or gauzethat has been saturated with a possible allergen (a sub-stance capable of producing an allergic reaction) is ap-plied to the skin. The test result is positive if redness orswelling develops.

99DIAGNOSTIC TESTS

Urtica is the Latin

word for the nettle

plant. Urticaria, or

hives, are temporary

lesions that are

similar to the ones

you get when you

accidentally rub up

against a nettle.

845505.qxd 8/19/08 4:54 PM Page 99

Scratching the surfaceAnother method for detecting allergies is the scratchtest. This test involves inserting small amounts of possi-ble allergens into scratches on the skin surface andwatching for a sensitivity reaction.

CulturesGram stains rapidly provide diagnostic informationabout which organism is causing an infection. A Gramstain separates bacteria into two categories based on cellwall composition. Gram-positive organisms retain crys-tal violet stain after decoloration. Gram-negative organ-isms lose the violet stain but stain red with safranine.

The Tzanck test requires smearing vesicular fluid ordrainage from an ulcer on a glass slide, thenstaining the slide with several chemicals. Herpesvirus infection is confirmed by examining the flu-id under a microscope. (See How do I sayTzanck?)

A sensitive matterA culture is used to isolate and identify an infec-tious agent. In a culture, a sample of tissue or flu-id is placed in a jellylike medium that providesnutrients for microorganisms. If an organism ispresent, it may multiply rapidly or may take sev-eral weeks to grow.

A sensitivity test determines the drug thatwill best treat an infection. Drugs are added to a culturedsample to see which ones kill the offending organism.


The scratch

test involves

inserting small

amounts of

possible allergens

into scratches on

the skin surface

and watching for

a sensitivity

reaction.

Named after Arnault Tzanck (1886-1954), a Russian dermatologistwho worked in Paris, the Tzanck test requires smearing vesicu-lar fluid or drainage from an ulcer on a glass slide, then stainingthe slide with several chemicals. The t sound in Tzanck is silentas is the t sound in tsar. Therefore, Tzanck is pronounced ZANK.


How do I say Tzanck?

845505.qxd 8/19/08 4:54 PM Page 100

Biopsies and smear testsA biopsy is the removal of tissue for microscopic exami-nation. Below are types of biopsies used for skin disor-ders:• A skin biopsy is used to test a small piece of tissuefrom a lesion suspected of malignancy or other disorder.• In a shave biopsy, the lesion is shaved above the skinline, leaving the lower layers of dermis intact.• In a punch biopsy, an oval plug is removed from thecenter of a lesion.• An excision biopsy may be used to remove an entirelesion, if it’s small enough.

A smear campaignA somewhat less invasive method than biopsy is thesmear test, in which cells are spread on a slide and stud-ied under a microscope. In the buccal smear test, cellsare scraped from the inner surface of the cheek to detecthereditary abnormalities.

Tools of the tradeDuring phototesting, small areas of skin are exposed toultraviolet light to detect photosensitivity (acute sensitiv-ity to light). A Wood’s light is an ultraviolet light that’sused to diagnose tinea capitis. Hairs infected by thisfungus appear fluorescent under a Wood’s light.

Disorders

Skin forms a barrier against the environment and also re-flects problems within the body, so it’s an easy target forinfection, injury, and infestation.

Bacterial infectionsBelow are some common bacterial infections:• Impetigo is a contagious, superficial skin infectionthat’s usually caused by Staphylococcus aureus. Impetigolesions start as macules, then develop into vesicles thatbecome pustular with a honey-colored crust. When the

101DISORDERS

845505.qxd 8/19/08 4:54 PM Page 101

vesicle breaks, a thick yellow crust forms from the exu-date.• Cellulitis is an inflammation of subcutaneous and der-mal tissues caused by a bacterial infection. It often ap-pears around a break in the skin, such as an insect bite ora puncture wound. The affected area is red, swollen, andwarm. Fever, chills, headache, and tiredness commonlyaccompany cellulitis.• Folliculitis is a bacterial infection of the hair folliclesthat’s usually caused by S. aureus. A furuncle, or boil,begins deep in the hair follicles. When a boil spreads tosurrounding tissue and produces a cluster of furuncles,it’s called a carbuncle.• A stye is an abscess in the eyelash follicle that’s causedby a staphylococcal infection.

Viral infectionsTwo common manifestations of viral infections are thesores associated with different types of herpes andwarts.

A not-so-simple(x) infectionThe word herpes, often used as a singular word, actuallyrefers to a variety of viruses. Below are some commontypes of herpes:• Herpes simplex virus type 1 causes painful coldsores and fever blisters on the skin and mucous mem-branes. After initial infection, patients are susceptible torecurrent bouts with the virus. Outbreaks are accompa-nied by burning pain, swelling, redness, and fatigue.• Herpes simplex virus type 2, also known as genitalherpes, produces lesions in the genital area. Patientscomplain of flulike signs and symptoms, includingheadache, fatigue, muscle pain, fever, and loss of ap-petite. Both herpes simplex types 1 and 2 are caused bycontact with an infected lesion.• Herpes zoster, also known as shingles, is caused byvaricella-zoster, the chickenpox virus. Lesions calledspinal ganglia appear along spinal nerve fibers outsidethe central nervous system. The virus is dormant untilthe patient’s resistance is low, then a row of vesicularskin lesions erupts along a spinal nerve pathway, accom-


Carbuncle means a

small live coal in Latin.

The burning and

glowing of hot coals is

an apt image for a

carbuncle, which is a

cluster of angry,

painful boils.

845505.qxd 8/19/08 4:54 PM Page 102

panied by severe pain, fever, and weakness. (See A creep-ing virus.)

As common as a toadVerrucae (warts) are common, harmless infections ofthe skin and mucous membranes. They’re caused by thehuman papillomavirus and can be transmitted by directcontact. Diagnosed by their appearance, warts are divid-ed into the following categories:• common (also called verruca vulgaris)—rough, ele-vated wart appearing most commonly on extremities, es-pecially hands and fingers• filiform—stalklike, horny projection commonly occur-ring around the face and neck• flat—multiple groupings of up to several hundredslightly raised lesions with smooth, flat, or slightly round-ed tops• genital (also called condyloma acuminatum)—sexu-ally transmitted infection appearing on the penis, scro-tum, vulva, and anus• periungual—rough wart appearing around the edgesof fingernails and toenails• plantar—appearing as a singular lesion or in largeclusters, primarily at pressure points of the feet, with le-sions that are slightly elevated or flat.

Parasitic infectionsPediculosis results from the infestation of bloodsuckinglice. These lice feed on human blood and lay their eggs,or nits, in body hair or clothing fibers. When a lousebites, it injects a toxin into the skin that produces mild ir-ritation and a reddened spot. Repeated bites can lead toserious inflammation. Three types of lice attack humans:• Pediculus humanus capitis, or head louse• Pediculus humanus corporis, or body louse• Phthirus pubis, or pubic louse (see Crabs, page 104).

The nesting instinctScabies, another common parasitic infection, is causedby a female mite that penetrates and burrows into theskin. Under the skin, the mite lays eggs that mature andrise to the surface. A scabies infestation produces intenseitching and secondary infections from the excoriation

103DISORDERS

A creeping virus

Hippocrates used theterm herpes, the Greekword for creeping, to de-scribe a spreading cuta-neous infection. Galenlater revived the termduring the 2nd centuryand diagnosed threetypes of the infection.Until the 18th century,the term was used for anumber of conditions, in-cluding varieties ofeczema and psoriasis.Around this time, Englishdoctor Robert Willan re-stricted its use to the de-finition used today.


845505.qxd 8/19/08 4:54 PM Page 103

caused by scratching. Wavy, brown, threadlike lines ap-pear on the hands, arms, body folds, and genitals.

Fungal infectionsDermatophytosis is the general name for a fungal infec-tion. Mushrooms, molds, and yeasts are common fungi(plural of fungus). Fungi are present in the air, soil, andwater, but only a few species of fungi cause disease.

One of the most common fungal disorders is tinea,or ringworm. Each type of tinea is named according tothe body part it affects:• Tinea barbae affects the bearded area of the face andneck. This infection produces raised areas that havemarked crusting.• Tinea capitis is characterized by small, spreadingpapules on the scalp that cause patchy hair loss withscaling.• Tinea corporis affects the body and produces lesionswith a ring-shaped appearance.• Tinea cruris, commonly called jock itch, producesred, raised itchy lesions on the groin and surroundingareas.• Tinea pedis is also called athlete’s foot. This infec-tion causes scaling and maceration between the toes, se-vere itching, and pain.• Tinea unguium, also called onychomycosis, usuallystarts at the tip of one or more toenails and producesgradual thickening, discoloration, and crumbling of thenail.

The red on a baby’s bottomCandidiasis, also called moniliasis, is a mild, superfi-cial fungal infection of the skin, nails, or mucous mem-branes. The patient develops a scaly, reddened papularrash with severe itching and burning. This fungus is oftenthe culprit in diaper rash and vaginal infections. It’s diag-nosed through skin scrapings.

The white on another set of cheeksThrush is a fungal infection of the oral mucous mem-branes caused by Candida albicans. This infection de-velops most commonly in patients whose defenses areweakened by illness, malnutrition, infection, or pro-


Crabs

In nonmedical settings,you’ll often hear pubiclice called crabs. Thismakes sense figurativelybecause pubic lice movein a crablike manner.Thus, the term crabs hasbecome common slangfor cases of sexuallytransmitted pubic lice.

The realworld

Remember to break

down seemingly

difficult words such

as dermatophytosis.In Greek, derma

means skin, phyto

means plant, and osis

means disease.

845505.qxd 8/19/08 4:54 PM Page 104

longed treatment with antibiotics. White patches developon a red, moist, inflamed surface inside the mouth, usual-ly the inner cheeks. Thrush is accompanied by pain andfever.

Inflammatory disordersDifferent types of dermatitis make up the most commoninflammatory skin disorders.

DermatitisSuperficial skin infections are known as dermatitis.Dermatitis can be caused by numerous things, includingdrugs, plants, chemicals, and food.

Hands off!Contact dermatitis occurs when direct contact with anirritant causes the epidermis to become inflamed anddamaged. Touching such substances as poison ivy, poisonoak, detergents, and industrial chemicals can lead topain, burning, itching, and swelling—signs and symptomsof dermatitis.

Other types of dermatitis include:• atopic dermatitis—a chronic inflammatory response.Atopic refers to a tendency to develop allergies, and der-matitis is an inflammation of the skin. The most com-mon symptoms are dry, itchy (pruritic) skin and rasheson the face, inside the elbows, on the hands and feet, andbehind the knees. Atopic dermatitis is often calledeczema.• exfoliative dermatitis—a severe chronic inflamma-tion characterized by peeling of the skin• localized dermatitis—a superficial inflammationcharacterized by redness and widespread erythema andscaling• nummular dermatitis—a chronic form of dermatitischaracterized by coin-shaped, pruritic, crusted scales• seborrheic dermatitis—an acute or subacute skindisease that primarily affects the scalp and face and ischaracterized by dry or moist greasy scales and yellowishcrusts• stasis dermatitis—fragility with fibrous changes ofthe skin that are accompanied by tan pigmentation,

105DISORDERS

845505.qxd 8/19/08 4:54 PM Page 105

patchy redness, and petechiae; typically caused byswelling from impaired venous circulation.

Other inflammatory disordersHere are some other inflammatory skin disorders, includ-ing allergies.

Don’t eat that!Angioedema is characterized by urticaria and edemathat occur as an allergic reaction, usually to a certainfood. It occurs in the subcutaneous tissues of isolatedareas, such as the eyelids, hands, feet, tongue, larynx,GI tract, or lips.

Silvery scalesPsoriasis is a chronic skin disorder, commonly with un-known causes, that’s characterized by periods of remis-sion and worsening. Psoriasis usually starts between ages25 and 30. Lesions appear as reddened papules andplaques covered with silvery scales; they vary widely inseverity and location.

Skin tumorsMost skin tumors are benign (noncancerous), but theycan be a starting point for skin cancer.

An angioma is formed by a group of blood vesselsthat dilate and form a tumorlike mass. A port-wine birth-mark is a typical angioma. Spider angiomas, also calledtelangiectases, are made up of tiny, dilated veins thatspread outward with a spiderlike appearance. (SeeCaught in a web.)

Not so benign…Basal cell carcinoma is a type of skin cancer arising inthe basal cell layer of the epidermis. Commonly found onthe face and upper trunk, these tumors are painless andmay go unnoticed by the patient.

Squamous cell carcinoma, another form of skincancer, begins in the epidermis and produces a firm,nodular (knotlike) lesion covered with a crust or a cen-tral ulceration.


To pronounce

psoriasis, think

of the word

“sore.” The p is

silent.

Caught in a web

The word telangiectases

derives from Greek. Tela

is the Greek term forweblike, angiis a Greekaffix for vessels, and ec-

tasia is the Greek wordfor distended. Put themall together and youhave a good descriptionof telangiectases—dis-tended weblike veins.


845505.qxd 8/19/08 4:54 PM Page 106

…and malignantIn malignant melanoma, cancer arises from themelanocytes (pigment cells) of the skin and its under-lying structures. There are three types of malignantmelanoma, which are categorized by location and de-scription:• Superficial spreading melanoma arises from an areaof chronic irritation and is characterized by irregular col-ors and margins.• Nodular melanoma grows vertically, invading the der-mis and metastasizing early.• Lentigo maligna melanoma arises from a lentigo ma-ligna on an exposed skin surface and features a large le-sion with scattered black nodules.

Cutaneous ulcersAn ulcer is an open sore. Ulcers on the skin are usuallycaused by a lack of circulation to a vulnerable area. Ul-cers may be superficial, caused by local skin irritation,or deep, originating in the underlying tissue.

Under pressurePressure ulcers are localized areas of cellular death thatoccur most commonly in the skin and subcutaneous tis-sue over bony prominences. Increased pressure impairscirculation.

Not in a good flowStasis ulcers are caused by chronic venous stasis(poor blood flow) due to inefficient or obstructed veins.Prolonged standing in one position and obesity are pre-disposing factors for stasis ulcers.

Burns and cold injuryThe skin is an effective protective covering.It can, however, be severely damaged when itcomes in contact with excessive heat or cold.

Too hotA burn is an injury to tissue caused by con-tact with dry heat (fire), moist heat (steam),

107DISORDERS

Remember,

ulcer comes

from the Latin

word ulcus,

which means

sore.

845505.qxd 8/19/08 4:54 PM Page 107

electricity, chemicals, lightning, or radiation. Categorizedaccording to depth, burns are referred to as superficial,partial-thickness, or full-thickness. When named ac-cording to severity, burns are called first, second, third,or fourth degree. (See Assessing burns.)

Too coldCold injury, or frostbite, results from overexposure tocold air or water. Upon returning to a warm place, a per-son with superficial frostbite experiences burning, tin-gling, numbness, swelling, and a mottled, blue-gray skincolor. Deep frostbite causes pain, blisters, tissue death,and gangrene. The skin appears white until it thaws andthen appears purplish blue.

Other skin disordersHere are some other common skin disorders:• acne—an inflammatory skin eruption caused byplugged sebaceous glands, resulting in papules and pus-tules• albinism—an inherited condition of defective melaninproduction, causing lack of pigmentation to the skin• alopecia—hair loss• aphthous stomatitis (canker sores)—recurring ul-cers on the mucous membrane of the mouth, with small,white lesions


Assessing burns

Assessing a burn means determining the depth of skin and tissue damage. It’s traditional to describe burn depth by degrees,although most burns are a combination of different degrees and thickness.

First-degree, or superficial, burn

In a first-degree burn, damage is limited to the epidermis, caus-ing redness and pain. The skin is dry, with no blisters ordrainage. A sunburn is a type of first-degree burn.

Second-degree, or partial-thickness, burn

In a second-degree burn, the epidermis and part of the dermisare damaged, producing blisters and mild-to-moderate edemaand pain. Large, moist blisters may occur, and the skin is mot-tled with dull white, tan, pink, or cherry-red areas. Spilling a hotcup of coffee on the skin could produce a second-degree burn.

Third-degree, or full-thickness, burn

In a third-degree burn, the dermis and epidermis are damaged.No blisters appear, but white, brown, or black leathery tissueand thrombosed vessels are visible. Little or no pain accom-panies this burn because the nerves are damaged. The skindoesn’t blanche with pressure. Contact with hot liquids, flames,chemical, or electricity may cause a third-degree burn.

Fourth-degree burn

In a fourth-degree burn, damage extends through deeplycharred subcutaneous tissue to muscle and bone.

Chilblain is a

combination of

the English word

chill and the Old

English word for

sore, blain.

845505.qxd 8/19/08 4:54 PM Page 108

• chigger—the larvae of a mite, which attach to thehost’s skin, causing severe itching and dermatitis• chilblain—redness, burning, and swelling of the skincaused by exposure to cold, damp conditions• nevus—a benign birthmark• rosacea—a chronic skin disease that causes dilatedand inflamed surface blood vessels and reddening of thenose and adjoining areas; commonly is accompanied byacne (acne rosacea)• vitiligo—irregularly shaped patches of lighter or whiteskin caused by the loss of pigment-producing cells.

Treatments

Treating skin disorders is an example of hands-on healthcare. Most medicines are applied topically (to the affect-ed area only). Surgery is typically performed with only alocal anesthetic, and monitoring depends mostly onsimple observation.

Drug therapyDrugs used to treat skin disorders include local anti-infectives to treat infection, topical corticosteroids toreduce inflammation, protectants to prevent skin break-down, keratolytics to loosen thickened layers of skin,astringents to shrink tissues, and emollients anddemulcents to soothe the skin.

Laser surgeryThe word laser stands for “light amplification by thestimulated emission of radiation.” The highly focused andintense light of lasers is used to treat many types of skinlesions. Performed on an outpatient basis, laser surgerytypically spares normal tissue (with the exception of car-bon dioxide [CO2] lasers), promotes healing, and helpsprevent postsurgical infection.

Set your lasers on…Three types of lasers are used in dermatology:• The blue-green light of argon lasers is absorbed by thered pigment in hemoglobin. It coagulates small blood ves-sels and treats superficial vascular lesions.

109TREATMENTS

845505.qxd 8/19/08 4:54 PM Page 109

• The CO2 laser emits an invisible beam in the far-infrared wavelength; water absorbs this wavelength andconverts it to heat energy. This laser helps treat wartsand malignancies.• The tunable dye laser is also absorbed by hemoglobinand has successfully treated port-wine stains.

Other surgeryCryosurgery causes epidermal-dermal separation abovethe basement membranes, which prevents scarring. Inthis common dermatologic procedure, the application ofextreme cold leads to tissue destruction. It can be per-formed simply by applying liquid nitrogen to the skinwith a cotton-tipped applicator or may involve a complexcryosurgical unit.

Mohs’ micrograph surgery involves excising (cut-ting out) the smallest possible amount of cancerous tis-sue in a step-by-step manner to determine whether allcancer cells have been removed. This procedure helpsprevent cancer recurrence by removing all malignant tis-sue.

No more childhood scarsDermabrasion is the removal of superficial scars on theskin using revolving wire brushes or sandpaper. Derma-brasion is typically used to reduce facial scars caused byacne.

Skin graftsSkin grafts cover defects caused by burns, trauma, orsurgery. They’re used when primary closure of the skinisn’t possible or cosmetically acceptable, when the defectis on a weight-bearing surface, when primary closurewould interfere with functioning, and when a skin tumoris excised.

Types of skin grafts include:• split-thickness grafts, which consist of the epidermisand a small portion of dermis• full-thickness grafts, which include all of the dermisas well as the epidermis• composite grafts, which also include underlying tis-sues, such as muscle, cartilage, and bone.


I don’t know why I’m

crying. Cryosurgerymay sound

complicated but it’s

often just liquid

nitrogen applied to

the skin with a

cotton-tipped

applicator.

845505.qxd 8/19/08 4:54 PM Page 110

The gift of the graftAn autologous graft, or autograft (auto- means self),is taken from the patient’s own body and is the most suc-cessful type of skin graft. A graft from a genetically simi-lar person, such as a twin, is an isologous graft, or iso-graft (iso- means alike).

Patching it upBiological dressings function like skin grafts to easepain and prevent infection and fluid loss. However,they’re only temporary; eventually the body rejects them.If the underlying wound hasn’t healed, these dressingsmust be replaced with an autologous graft.

There are four types of biological dressings:• Homografts (allografts), which are harvested fromcadavers, are rejected in 7 to 10 days. They’re used to de-bride wounds, protect new tissue growth, serve as testgrafts before skin grafting, and temporarily cover burns.(Allo is Greek for deviating from normal and homorefers to human beings.)• Heterografts (xenografts), grafts harvested from an-imals (usually pigs), are also rejected after 7 to 10 days.They’re used for the same purposes as homografts andare also used to cover exposed tendons and burns thatare only slightly contaminated.• Amnion, made from the amnion and chorion mem-branes (fetal membranes), is used to protect burns andtemporarily cover new tissue while awaiting an auto-graft.• Biosynthetic grafts, which are woven from man-made fibers, are used to cover donor graftsites, protect wounds awaiting autografts,and cover meshed autografts.

DebridementDebridement is the use of mechanical,chemical, or surgical techniques to removenecrotic (dead) tissue from a wound. Al-though it can be extremely painful, debride-ment is necessary to prevent infection andpromote healing of burns and skin ulcers.

There are three types of debridement:

111TREATMENTS

Debridement is

borrowed from the

French and means to

unbridle. Originally a

medical term, it was

first used to describe

the cutting of

constricting bands—

similar to a horse’s

bridle.

845505.qxd 8/19/08 4:54 PM Page 111

• Chemical debridement involves special wound-clean-ing beads or topical medications, which absorb drainageand debris from a wound. These agents also absorb bac-teria, reducing the risk of infection.• Mechanical debridement may involve dressings, irri-gation, hydrotherapy (whirlpool baths), or bedside re-moval of necrotic tissue. During bedside debridement,dead tissue is scraped off or cut away with a scalpel orscissors.• Surgical debridement requires anesthesia and is usu-ally reserved for burn patients or those with extremelydeep or large ulcers.

Therapeutic bathsAlso known as balneotherapy, baths are used to treatmany skin conditions, including psoriasis, eczema, exfo-liative dermatitis, and bullous diseases that cause blis-ters.

The four types of baths commonly used are antibac-terial, colloidal, emollient, and tar. In addition to pro-moting relaxation, these baths permit treatment of largeareas. Therapeutic baths are limited to 30 minutes be-cause they can cause dry skin, itching, scaling, and fis-sures. (See The baths.)

PhototherapyUsed to treat skin conditions such as psoriasis by expo-sure to ultraviolet radiation, phototherapy slows thegrowth of epidermal cells, most likely by inhibiting thesynthesis of deoxyribonucleic acid. Two different ultravi-olet light wavelengths are used: ultraviolet A (UVA) is thecomponent of sunlight that tans skin and ultraviolet B isthe component that causes sunburn.

Light plus drugs equals…Photochemotherapy is a treatment in which a drugcalled psoralen is given to the patient to make his skinmore sensitive to UVA light. The combination of psoralenwith UVA is also known as PUVA therapy.


The baths

There are four types oftherapeutic baths:• Antibacterial baths areused to treat infectedeczema, dirty ulcera-tions, and furunculosis.Acetic acid, hexachloro-phene, potassium per-manganate, and povi-done iodine are com-monly used.• Colloidal baths relieveitching and soothe irritat-ed skin. They’re indicat-ed for any irritating oroozing skin condition,such as atopic eczema.Oatmeal, starch, andbaking soda are used forcolloidal baths.• In emollient baths,

bath oils and mineral oilare used to clean andhydrate the skin. They’rehelpful for any dry skincondition.• In tar baths, specialbath oils are used withtar or coal tar concen-trate to treat scaly skindisorders. This bathloosens scales and re-lieves itching.

845505.qxd 8/19/08 4:54 PM Page 112


Across

3. An excess of this enzyme turnsthe skin yellow-orange7. The outermost layer of skin9. A fluid-filled lesion12. Word that describes pale skin

Down

1. The specialized cells in the skinlayer that enhance the immunesystem are named after this doctor2. The Greek word for skin4. Glands that begin to function atpuberty

5. A contagious, superficial skin in-fection6. A protein that gives strength tothe dermis8. Caused by female mites10. Crescent-moon-shaped areaon the nail

11. Condition of normal tension inthe skin


Get ready to

toughen up!

These puzzles

are pretty

difficult.

Vocabulary builders

At a crossroadsHopefully, this is a crossword puzzle that won’t get under yourskin. Good luck!

1 2

3

4 5 6

7 8

9 10 11

12

845505.qxd 8/19/08 4:54 PM Page 113



1.

2.

3.


Finish lineOne of the most common fungal disorders is tinea. Each specific type of tinea is namedaccording to the body part it affects. Fill in the blanks to complete each type of thisfungal disorder.

1. Tinea ______________ affects the bearded area of the face and neck.

2. Tinea ______________ produces raised itchy lesions in the groin area.

3. Tinea ______________ is also called athlete’s foot.

4. Tinea ______________ usually starts at the tip of one or more of the toenails.

5. Tinea ______________ affects the body.

6. Tinea ______________ is characterized by small papules on the scalp.

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1. ____ ____ ____ ____ ____ ____ ____ ____ ____ ____

2. ____ ____ ____ ____ ____ ____ ____ ____

3. ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____

4. ____ ____ ____ ____ ____ ____ ____ ____

5. ____ ____ ____ ____ ____ ____ ____ ____ ____

1. Areas of nerve fibers2. From the Latin, meaning scalelike3. The term used to describe the removal of dead tissue from a wound4. Hair loss5. A word from the English word for chill and the Old English word for sore

You’re working at

a “blistering” pace.

What skin lesion are

you likely to get?


845505.qxd 8/19/08 4:54 PM Page 115


1. Barbae; 2. Cruris; 3. Pedis; 4. Unguium; 5. Corporis; 6. Capitis

Finish line

1. Sebaceous; 2. Verrucae; 3. Petechia

O see, can you say?

1. Dermatomes; 2. Squamous; 3. Debridement; 4. Alopecia; 5. ChilblainAnswer to puzzle—Bulla

Talking in circles

At a crossroads

Answers

Good goin.’

Let’s move on

to the

cardiovascular

system without

skipping a beat.

1L

2D

3C A R O T E N E

N R4A G

5I M

6C

7E P I D E R M I

8S A O

O R P C L

C H E A L

R A T9B U

10L L A

11T

I N I I U G U

N S G E N E R

E O S U N G

L O12P A L L O R

845505.qxd 8/19/08 4:54 PM Page 116

Heart structure and function

A key to learning terminology related to the cardiovascu-lar system is knowing the medical word for heart: it’s theLatin word cardium, which is borrowed from the Greekword kardia. Cardium is often combined with otherwords in the forms cardi or cardio. Some examples in-clude cardiology, electrocardiogram, and tachycardia.(See Cardiac versus heart and Pronouncing key cardio-vascular system terms, page 118.)

The heart’s protectorThe heart is protected by a thin sac called the pericar-dium. Peri- is a Greek prefix that means around. Thepericardium has an inner, or visceral, layer that formsthe epicardium and an outer, or parietal, layer.

A three-layered heartThe heart wall is composed of three layers. The outerlayer is the epicardium. Epi- is a Greek prefix thatmeans on. The myocardium is the heart muscle itself,

6

Health assessmentCardiovascular system

Just the facts


♦ terminology related to the structure and function ofthe cardiovascular system

♦ terminology needed for physical examination of thecardiovascular system

♦ tests that help diagnose cardiovascular disorders

♦ disorders of the cardiovascular system and theirtreatments.

Cardiac versusheart

The word cardiac isnearly as familiar to mostEnglish-speaking peopleas the word heart. Be-cause Greek and Latinwere the primary lan-guages of universities upuntil the 1900s, termsfrom those languageswere adopted for scien-tific use. Some of thoseterms, like cardiac, havemigrated into ordinaryEnglish speech as well.


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and the endocardium is the innermost layer, which linesthe heart’s chambers and covers its valves. Endo- is aGreek prefix that means within.

Welcome to my chambersThe heart consists of four chambers. Each of the two up-per chambers is called an atrium (plural: atria). Theatria are thin-walled chambers that serve as reservoirsfor blood. Each atrium is connected by its own valve to achamber below it. The two lower chambers are calledventricles (also called ventriculi). The ventricles havethick walls and are responsible for pumping bloodthroughout the body. (See Why the atria are called atria.)

118CARDIOVASCULAR SYSTEM

Below is a list of key terms, along with the correct ways to pronounce them.


Pronouncing key cardiovascular system terms

Why the atriaare called atria

It’s fitting that the upperchambers of the heartare called atria because,in a Roman house, theatrium was an entrancewhere a person wasgreeted before movinginto other rooms. Theatria are the first cham-bers in the heart to re-ceive blood before itempties into the ventri-cles and is pumpedthroughout the body.

And those ventricles?

The word ventricle de-rives from the Latin wordventriculus, whichmeans little stomach andrefers to any small cavityof the body. There aretwo ventricles in theheart and four in thebrain.


Aneurysm

Angina

Arrhythmia

Arteriosclerosis

Coarctation

Defibrillation

Diuretic

Electrophysiologic

Ischemia

Paroxysmal atrial tachycardia

Pericardiocentesis

Prinzmetal angina

Sphygmomanometer

Thrombophlebitis

AN-YOU-RIZM

AN-JEYE-NUH

AH-RITH-MEE-UH

AR-TEER-EE-OH-SKLER-OH-SIS

KOH-ARK-TAY-SHUHN

DEE-FIB-RUH-LAY-SHUHN

DEYE-YUH-REH-TIK

E-LEK-TROH-FIZZ-EE-OH-LOJ-IK

IS-KEE-MEE-UH

PAR-OK-SIZZ-MUHL AY-TREE-UHL TAK-EH-KAR-DEE-UH

PER-UH-KAR-DEE-OH-SEN-TEE-SIS

PRINTS-MET-UHL AN-JEYE-NUH

SFIG-MOH-MAHN-OM-UH-TER

THROM-BOH-FLEH-BEYE-TIS

845506.qxd 8/19/08 5:05 PM Page 118

Blood’s pathBlood is carried into the heart through several major ves-sels, all of which empty into either the superior venacava or inferior vena cava (plural: venae cavae). Thesuperior vena cava carries blood from the upper body tothe right atrium; it’s called superior because that meansnear the top. Inferior means situated below, and the in-ferior vena cava carries blood from the lower body to theright atrium. (See How do I say vena cava?)

Through the pulmonary artery and into the lungsBlood in the right atrium empties into the right ventriclemostly by gravity. When the ventricle contracts, the bloodis ejected into the pulmonary artery (called such be-cause pulmon is the Latin word for lung). The blood ispushed through the pulmonary arteries to the lungs.

The final tripFrom the lungs, blood travels to the left atrium throughthe pulmonary veins. The left atrium empties blood intothe left ventricle. The left ventricle pumps the blood intothe aorta and, from there, it travels throughout the body.(See Why call it the aorta?)

The heart’s valvesThe heart contains two atrioventricular (AV) valves(the tricuspid and mitral) and two semilunar valves (thepulmonic and aortic). The tricuspid valve separates theright atrium from the right ventricle. It has three flaps orcusps.

The pulmonic valve separates the right ventriclefrom the pulmonary artery.

119HEART STRUCTURE AND FUNCTION

In the term vena cava, the first word looks like the word vein,

and that’s exactly what it means. It’s pronounced VEE-NAH. Thesecond word is pronounced with a long first a and a short final asound, CAY-VAH. The plural venae cavae, pronounced VEE-NAY

KAH-VAY, refers to both veins.


How do I say vena cava?

Why call it theaorta?

Aorta means that whichis hung. Because of thearching curve in the aor-ta as it exits the heartand its subsequent de-scent into the body, itlooks something like amodern clothes hanger.Apparently, Aristotle hada similar notion; he wasthe first to apply thename to this artery.


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The mitral valve separates the left atrium from theleft ventricle. It has two flaps or cusps and is also knownas the bicuspid valve. (See Inside the heart.)


This illustration shows a cross-sectional view of the structures and blood flow of the heart and major blood vessels.


Inside the heart

Superior vena cava

Branches of rightpulmonary artery

Right atrium(AY-TREE-UHM)

Right pulmonary veins

Tricuspid valve

Right ventricle

Inferior vena cava

Pulmonary semilunar valvePulmonary artery

Aortic arch

Branches of left pulmonaryarteryLeft atrium

Left pulmonary veins

Mitral valve

Aortic semilunar valveMyocardiumLeft ventricle

Descending aorta

Heart wall

Endocardium(EN-DOH-KAR-DEE-UHM)Myocardium(MEYE-OH-KAR-DEE-UHM)Epicardium(EP-UH-KAR-DEE-UHM)

Pericardial spacePericardium(PER-EE-KAR-DEE-UHM)

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The heart’s rhythmContractions of the heart occur in a rhythm—the cardiaccycle—and are regulated by impulses that normally beginat the sinoatrial (SA) node, the heart’s pacemaker. Theimpulses are conducted from there through the AV node,down through the AV bundle, or the bundle of His (pro-nounced HIHS), and through the Purkinje fibers, wherethe impulse stimulates ventricular contraction. (SeeWhat’s a Purkinje?)

For every opposite actionThe autonomic nervous system has two divisions thathave opposite actions on the heart. The parasympa-thetic division acts on the SA and AV nodes. This divi-sion slows heart rate, reduces impulse conduction, anddilates coronary arteries.

The sympathetic division also acts on the SA and AVnodes but with an opposite effect. This division increasesheart rate and impulse conduction and constricts and di-lates the coronary arteries.

Cardiac cycleNo discussion of heart functions would be completewithout an explanation of the cardiac cycle, the periodfrom the beginning of one heartbeat to the beginning ofthe next. During this cycle, electrical and mechanicalevents must occur in the proper sequence and to theproper degree to provide adequate blood flow to all bodyparts. (See Cardiac conduction route, page 122.)

The two phasesThe cardiac cycle has two phases: systole and diastole.Systole is the period when the ventricles contract andsend blood on an outward journey to the aorta or the pul-monary artery. Diastole is when the heart relaxes andfills with blood. During diastole, the mitral and tricuspidvalves are open, and the aortic and pulmonic valves areclosed. (See Systole and diastole, page 122.)

Diastole—passive then activeDiastole consists of two parts, ventricular filling andatrial contraction. During the first part of diastole, 70%


The mitral

valve looks like a

bishop’s miter—

hence the name

mitral valve.

What’s aPurkinje?

The Purkinje (PUHR-KIN-JEE) fibers are micro-scopic muscles first dis-tinguished from ordinaryheart muscle tissue bythe Czech physiologistJan Purkinje (1787-1869),who also originated theanalysis and classifica-tion of fingerprints.


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of the blood in the atria drains into the ventricles as a re-sult of gravity, a passive action.

The active period of diastole, atrial contraction (alsocalled atrial kick), accounts for the remaining 30% ofblood that passes into the ventricles. Diastole is also theperiod in which the heart muscle receives its own supplyof blood, which is transported there by the coronaryarteries.

Lub…Systole is the period of ventricular contraction. As pres-sure within the ventricles rises, the mitral and tricuspid


Specialized fibers propagate electrical impulses throughout the heart’s cells, causing the heart tocontract. This illustration shows the elements of the cardiac conduction system.


Cardiac conduction route

Systole anddiastole

Systole (pronouncedSIS-TOH-LEE) and dias-

tole (pronounced DEYE-AH-STOH-LEE) have thesame Greek root, stole,

which means to send.

Apart or together?

The prefixes are the keysto these words. The pre-fix dia- means apart; andsy-, a contraction ofsyn-, means together. Ifyou think about the re-laxation of the muscleand the walls movingapart, you’ll rememberdiastole. If you thinkabout the interior wall ofthe ventricles contract-ing, coming closer to-gether, you’ll remembersystole.


Sinoatrial node(SEYE-NOH-AY-TREE-UHL)

Atrioventricularnode

Bundle of His

Right bundlebranch

Ventricular muscle

Atrial musclefibers

Left bundlebranch

Purkinje fibers


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C1INCREDIBLY EASY MINIGUIDE: THE HEART

The Latin

word cardium,

which is borrowed

from the Greek

word kardia, is

the medical word

for heart.

Cardium is commonly

combined with other words

in the forms cardi or cardio.

Some examples include

cardiology, pericardium,electrocardiogram, and

tachycardia.

Incredibly Easy miniguide: The heart

A key to learning

terminology related to

the cardiovascular

system is knowing the

medical word for heart.

8455CP1.qxd 8/19/08 7:55 PM Page C1

C2INCREDIBLY EASY MINIGUIDE


The superior

vena cava suppliesthe right atrium with

blood.

The right atrium formsthe uppermost part of the

heart’s right border. Itreceives blood from the

superior vena cava.

The right andleft ventricles areseparated by theinterventricular

septum.

Within the heart lie four chambers (two atria and two ventricles). A system of blood vessels carries blood to and from the heart.

The pulmonary

veins transportblood from the lungs

back to the heart.

The right ventricle

pumps blood into thepulmonary trunk and to

the lungs.

The left

ventricle ejectsblood into the

aorta.

The aorta, thelargest artery, branchesinto vessels that supply

blood to organs and otherareas of the body.

8455CP1.qxd 8/19/08 7:55 PM Page C2

C3INCREDIBLY EASY MINIGUIDE: THE HEART

The pulmonic valve, asemilunar valve,

prevents the backflow ofblood from the

pulmonary artery intothe right ventricle.

The semilunar valves of the heart have three cusps that are shaped like half-moons. The two atrioventricular valves separate the atriafrom the ventricles.

The right

atrioventricular

valve, also calledthe tricuspid valve,

has three triangularcusps, or leaflets.

The aortic valve,

another semilunar valve,prevents backflow ofblood from the aortainto the left ventricle.

How did the

semilunar valves

get their name?

They’re shaped like

half-moons.The left

atrioventricular valve,

also called the mitral

or bicuspid valve,

contains two cusps, alarge anterior and a

smaller posterior.

Anterior

Posterior


8455CP1.qxd 8/19/08 7:55 PM Page C3



The right coronary artery

supplies blood to the rightatrium (which includes

the sinoatrial andatrioventricular nodes), partof the left atrium, most of the

right ventricle, and theinferior part of the left

ventricle.

The heart relies on the coronary arteries and their branches for its supply of oxygenated blood.

I rely on

arteries for

my blood

supply.

The left coronary

artery splits intothe anterior

interventricular andcircumflex arteries.

The anterior

interventricular

artery suppliesblood to the

interventricularseptum and anterior

walls of bothventricles.

Thecircumflex

artery suppliesblood to the

the left atriumand the

posterior wallsof the leftventricle.

8455CP1.qxd 8/19/08 7:55 PM Page C4

valves snap closed. This closure leads to the first heartsound, S1 (the lub of lub-dub).

When the pressure in the ventricles rises above thepressure in the aorta and pulmonary artery, the aorticand pulmonic valves open. Blood then surges from theventricles into the pulmonary artery to the lungs and intothe aorta to the rest of the body.

…then dubAt the end of ventricular contraction, pressure in the ven-tricles drops below the pressure in the aorta and the pul-monary artery. That pressure difference forces blood toback up toward the ventricles and causes the aortic andpulmonic valves to snap shut, which produces the secondheart sound, S2 (the dub of lub-dub). As the valves shut,the atria fill with blood in preparation for the next periodof diastolic filling, and the cycle begins again.

Pumping it outCardiac output refers to the amount of blood pumpedout by the heart in 1 minute and is determined by thestroke volume, the amount of blood ejected with eachheartbeat multiplied by the number of beats per minute.Stroke volume, in turn, depends on three factors:• Contractility refers to the ability of the myocardiumto contract normally.• Preload is the stretching of muscle fibers in the ventri-cles. This stretching results from the volume of blood inthe ventricles at the end of diastole. The more musclesstretch, the more forcefully they contract during systole.• Afterload refers to the pressure the ventricular mus-cles must generate to overcome the higher pressure inthe aorta.

Vascular networkThe peripheral vascular system consists of a network ofarteries, arterioles, capillaries, venules, and veins.

Keep air in thereArtery comes from the Greek words aer, which meansair, and terein, which means to keep, because the an-cients believed that arteries contained air. Arteries carryblood away from the heart. Nearly all arteries carry


Coronaryarteries got their

name because they

encircle the heart

like a crown. The

word coronarycomes from the

Greek koron, which

means crown.

845506.qxd 8/19/08 5:05 PM Page 123

oxygen-rich blood from the heart to the rest of the body.The only exception is the pulmonary artery, which carriesoxygen-depleted blood to the lungs.

Smaller and smallerThe exchange of fluid, nutrients, and metabolic wastesbetween blood and cells occurs in the capillaries. Capil-laries are connected to arteries and veins through inter-mediary vessels called arterioles and venules, respec-tively. (See Call it a capillary.)

You’re so veinVeins carry blood toward the heart. Nearly all veins carryoxygen-depleted blood. The sole exception to this is thepulmonary vein, which carries oxygen-rich blood fromthe lungs to the heart.


This section introduces terms associated with examina-tion of the heart and abnormalities an examination mightreveal.

Vital signsThe physiologic condition of a patient is reflected in hisvital signs. The vital signs that are directly related to thecardiovascular system are pulse and blood pressure.

Stay on the beatA patient’s pulse is the expansion and contraction of anartery in a regular, rhythmic pattern; this happens whenthe left ventricle of the heart ejects blood into the aortaas it contracts, causing waves of pressure.

We thrive on pressureA person’s blood pressure is maintained by the complexinteraction of the homeostatic mechanisms of the bodyand is influenced by the volume of blood, the lumen ofthe arteries and arterioles, and the force of the cardiaccontraction.


Call it acapillary

Capillary is a Latin wordthat means hairlike. Itrefers to the minute sizeof these vessels.


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When you take a blood pressure, you’re measuringthe pressure exerted by the circulating volume of bloodon the walls of the arteries, the veins, and the chambersof the heart.

Systole and diastole againA typical blood pressure reading consists of systolicblood pressure and diastolic blood pressure; pulse pres-sure is a third measurement that depends on the othertwo pressures. Here’s a description of each:• Systolic blood pressure is the blood pressure causedby the contraction phase, or systole, of the left ventricleof the heart. It’s the top number given in a blood pressuremeasurement. For example, the systolic blood pressurein a measurement of 120/80 mm Hg is 120.• Diastolic blood pressure is the pressure during theheart’s relaxation phase, or diastole. It’s the bottom num-ber given in a blood pressure measurement. For example,the diastolic blood pressure in a measurement of120/80 mm Hg is 80.• Pulse pressure is the numerical difference betweenthe systolic and diastolic blood pressures. For example, ifthe patient’s blood pressure reading is 120/80 mm Hg, hispulse pressure is 40 mm Hg.

Tools of the tradeTo take a blood pressure, you use a sphygmo-manometer, an instrument that consists of an inflat-able cuff, an inflatable bulb, and a gauge, which isdesigned to measure arterial blood pressure.

You also listen to the sound of flowing bloodwith a stethoscope. The word stethoscope comesfrom the Greek words stethos, which means chest,and skopein, which means to examine. A stetho-scope is an instrument used for auscultation of respi-ratory, cardiac, intestinal, uterine, fetal, arterial, andvenous sounds; it consists of two earpieces that are con-nected by flexible tubing to a diaphragm, which is placedagainst the patient’s body.

What you hearIn determining blood pressure, you should listen forKorotkoff sounds, which are typically the first faint


Sphygmoma-…what? Oh, it’s

just a jazzed-up

name for a blood

pressure cuff.

845506.qxd 8/19/08 5:05 PM Page 125

sounds heard as the pressure in the cuff is released andblood begins to flow and the last sound heard before si-lence as blood flows. These two points correspond to thesystolic and diastolic pressures, respectively.

Abnormalities in the physical examinationAuscultation may reveal a murmur, a soft blowing orfluttering sound of cardiac or vascular origin, or a bruit,an abnormal sound heard over arteries that indicates tur-bulent blood flow. (See What’s all the bruit about?)

Color matters, tooOther signs of cardiovascular problems include cyano-sis, a bluish discoloration of the skin and mucous mem-branes that results from an excessive amount of deoxy-genated hemoglobin in the blood or a structural defect inthe hemoglobin molecule. The word cyanosis comesfrom the Greek word cyanos, which means dark blue.You may also encounter patients with pallor. Pallor isa fancy term for paleness, or a decrease or absence ofcolor in the skin.

Too much liquidThe examination can also reveal edema, the accumula-tion of abnormal amounts of fluid in the intercellular tis-sues, pericardial sac, pleural cavity, peritoneal cavity, orjoint capsules. Any of these conditions may be accompa-nied by diaphoresis, profuse perspiration associatedwith an elevated body temperature, physical exertion,heat exposure, and mental or emotional stress. (SeeEdema! That’s just swell!)

Too much painAngina, also called angina pectoris, is chest pain thatlasts several minutes and results from an inadequate sup-ply of oxygen and blood flow to the heart muscle.

Diagnostic tests

No single test can help diagnose cardiovascular disease.Therefore, your patient will undergo more than one—


What’s all thebruit about?

It’s easy to mispro-nounce bruit because it’sa French word. It meansnoise, din, or racket. It’spronounced BROOEE; thet sound is dropped.


Edema! That’sjust swell!

The word edema is a re-cent borrowing fromGreek. It means swelling.


845506.qxd 8/19/08 5:05 PM Page 126

sometimes several—tests if a cardiovascular disease ordisorder is suspected. These tests are described here.

Blood testsThree important blood tests may be used to help diag-nose cardiovascular problems.

Clotting by the clockActivated partial thromboplastin time, the test tomeasure the time required for formation of a fibrin clot,requires a blood sample to evaluate all the clotting fac-tors (except platelets) of the intrinsic pathway.

Any damage here?The cardiac enzyme test is used to determine if cardiactissue has been damaged. Normally present in high con-centrations within the heart muscle, cardiac enzymes arereleased into the bloodstream from their normal intracel-lular area during cardiac trauma and create an elevation ofthe serum cardiac enzyme levels. Elevated levels of theenzyme creatine kinase (CK) and the isoenzyme CK-MBover a 72-hour period usually confirm a myocardial infarc-tion (MI).

Did I have an MI?In the cardiac troponin test, a blood sample is used tomeasure the cardiac protein called troponin. This is themost precise way to diagnose an MI.

Radiologic testsHere are some terms for common radiologic tests:• Cardiac catheterization is a diagnostic procedure inwhich a catheter is inserted into a large artery or vein(usually in an arm or the groin) and then threadedthrough the vessel to the patient’s heart. After injection ofa radiopaque contrast medium, X-rays are taken to detectheart anomalies.• Angiocardiography creates an X-ray of the heart andgreat vessels after injection of contrast medium into ablood vessel or one of the heart chambers. (See Angio-cardiography, page 128.)

127DIAGNOSTIC TESTS

I know I’m

good-looking,

but a little

contrast

medium and an

X-ray really show

me off!

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• Angiography produces an X-ray of the blood vesselsafter injection of a radiopaque contrast medium.

Let’s see what’s going on in thereA radionuclide scan is a test that helps to measureheart function and damage. During this test, a mildly ra-dioactive material is injected into the patient’s blood-stream. Computer-generated pictures are used to locatethe radioactive element in the heart.

Running hot and coldThe thallium stress test helps diagnose coronary arterydisease. For this test, the patient is given a thallium iso-tope I.V. after a treadmill stress test. The isotope doesn’tcollect in areas of poor blood flow and damaged cells, sothese areas show up as “cold spots” on a scanner.

Other invasive testsElectrophysiologic studies are invasive tests that helpdiagnose conduction system disease and serious heartrhythm disturbances. The cardiologist (heart specialist)induces a rhythm disturbance by using different medica-tions or procedures. After identifying the source of therhythm disturbance, the cardiologist either administersmedications to terminate the disturbance or eliminatesthe abnormal pathway in the heart by treatment withhigh-frequency waves.


Pericardiocentesis and transesophageal look like hard words, but they’re easy to understand if broken apart.


Two troublesome terms

Angiocardiog-raphy

The word angiocardiog-

raphy looks overwhelm-ing but it becomes easierif you break it down. An-

gio- comes from theGreek word for vessel,cardi- means heart, and-graphy comes from theGreek word graphein,

which means to write.


Around the heart + puncture

Pericardiocentesis comes from the Greek word kentesis,

which means to puncture. The prefix peri- means around, andthe root cardio- means heart. Put it all together and you havethe meaning—a procedure that requires puncturing the sacaround the heart.

Through the esophagus

The first part of transesophageal, trans-, means through; there-fore, transesophageal means through the esophagus. Trans-esophageal echocardiography is an echocardiogram per-formed through the esophagus.

845506.qxd 8/19/08 5:05 PM Page 128

Pericardiocentesis is a surgical procedure in whichthe pericardium cavity is punctured for the aspiration offluid from the pericardial sac. This procedure can be per-formed for both diagnosis and treatment of some cardiacdisorders.

Transesophageal echocardiography is a techniquein which a probe is passed through the mouth and downthe esophagus to study the structure and motion of theheart using an echo obtained from beams of ultrasonicwaves directed through the esophagus. (See Two trouble-some terms.)

Noninvasive testsAn electrocardiogram (ECG) is a graphic record that’sproduced by an electrocardiograph and shows variationsin electrical potential, as detected at the body surface, re-sulting from excitation of the heart muscle. An ECG dis-plays a wave that represents phases of the cardiac cycle.(See Electrocardiogram.)

In a normal rhythm, the P wave is the first wave seenin the cardiac cycle. Atrial depolarization is representedon the ECG by the P wave. After atrial depolarization,electrical activity is absent for a brief period. This isknown as the PR interval.

Next, ventricular depolarization is represented on theECG by a waveform configuration known as the QRScomplex. After ventricular activation, ventricular repolar-ization begins. The ST segment represents the actual re-covery or repolarization of the ventricular muscle. The Twave represents the actual recovery.

Let me sound you outTransthoracic echocardiography is a diagnostic tech-nique that’s used to study the structure and motion of theheart by the echo obtained from beams of ultrasonicwaves directed through the chest wall. (See Did you hearan echo?)

129DIAGNOSTIC TESTS

Electrocardio-gram

The prefix electro-

comes from the Greekword elektron, whichrefers to the semi-precious stone amber.(Rubbing amber pro-duces an electriccharge.) Cardiogram

comes from the Latinword cardium, whichmeans heart, and theGreek term gramma,

which means mark.


Did you hear anecho?

In practice, you’ll com-monly hear echocardio-

graphy referred to as anecho. You’ll also hearcardiac catheterization

referred to as cath. Forexample, you might hearsomeone say, “Mrs.Heartman is scheduledfor her echo today.”

The realworld

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Disorders

Some cardiovascular problems occur suddenly and with-out warning, whereas others are long-term problems. Ei-ther way, when the heart is sick, the entire body is affect-ed. Many types of injury or illness cause problems for theheart, resulting in serious cardiac complications. (SeeCardiac complications.)

Types of cardiac disorders include:• cardiac arrhythmias• congenital heart defects• degenerative disorders• inflammatory heart disease• vascular disorders• valvular heart disease.

Cardiac arrhythmiasArrhythmia means the lack of normal heart rhythm (in-dicated by the prefix a-). A more accurate term to de-scribe what are commonly referred to as arrhythmias isdysrhythmia, which means an abnormality in rhythm.However, these terms are used interchangeably.

There are a number of different arrhythmias:• Atrial flutter is an arrhythmia in which atrial rhythmis regular, but the rate is 250 to 400 beats/minute. Theflutter waves that result have a sawtooth appearance.The ventricular rate is variable.


Cardiac complicationsHere’s a list of cardiac complications you may encounter:• Cardiac arrest is when the heart stops abruptly with an ab-sence of blood pressure or pulse.• In cardiac tamponade, blood or fluid fills the pericardial spaceand presses against the heart, compressing the heart cham-bers and obstructing venous return to the heart.• Cardiogenic shock, also called pump failure, results whenmore than 40% of the heart muscle is damaged by a myocardialinfarction. As a result, the heart can’t pump effectively and bodytissues don’t receive the necessary amounts of oxygen and nu-trients.

• Hypotension refers to blood pressure that’s below normal val-ues.• Hypovolemic shock occurs when reduced intravascularblood volume causes circulatory dysfunction and inadequateblood flow to tissues.• Pulmonary edema is an accumulation of excess fluid in thelungs.• Ventricular aneurysm is an outpouching of the ventricularwall that’s most commonly seen in the left ventricle.

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• Bradycardia is a slow heartbeat, usually less than60 beats/minute.• Fibrillation refers to an uncoordinated, irregular con-traction of the heart muscle, which may originate in theatria (atrial fibrillation) or in the ventricles (ventricularfibrillation). If left untreated, ventricular fibrillation canresult in cardiac arrest.• Heart block describes an impaired conduction of theheart’s electrical impulses at the AV node, which com-monly leads to a slow heartbeat.• Paroxysmal atrial tachycardia is an arrhythmia inwhich the atrial and ventricular rates are regular and ex-ceed 160 beats/minute. This arrhythmia is typically char-acterized by a sudden onset and termination.• Premature atrial contraction is an arrhythmia char-acterized by premature abnormal-looking P waves thatdiffer in configuration from normal P waves followed bynormal QRS complexes.• In premature ventricular contraction (PVC), theQRS complex is premature, wide, and distorted. PVCs oc-cur singly, in pairs, or in larger groups and alternate withnormal beats. They may originate from one or more sitesin the ventricles.• Tachycardia refers to a resting heartbeat greater than100 beats/minute.• Ventricular tachycardia is a potentially deadly ar-rhythmia in which QRS complexes are wide and bizarreand originate in the ventricles.

Congenital heart defectsCongenital means present at birth. Infants with congen-ital heart problems have structural defects of the heartor its blood vessels. The term blue baby describes cyan-osis that’s caused by several of these congenital defects:• Atrial septal defect is an opening between the twoatria. Because left atrial pressure is slightly higher thanright atrial pressure, blood shunts from left to right. Thisshunting causes an overload on the right side of theheart, which enlarges to accommodate the increased vol-ume.• Coarctation of the aorta is narrowing of the lumen(opening of the aorta), which results in high pressureabove and low pressure below the stricture.

131DISORDERS

Memoryjogger

To distin-guish brady-

cardia from tachy-cardia, think of anairplane either brak-ing (slowing down) ortaking off (speedingup) on the runway.

It seems like so

many things can

go wrong. It just

breaks my heart to

think about it!

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• Patent ductus arteriosus occurs when the ductusarteriosus, a passage between the aorta and pulmonaryartery that normally closes at birth, remains open, send-ing oxygenated blood back through the lungs.• The Tetralogy of Fallot got its name because it in-volves four (hence tetra-) major defects of the heart andgreat vessels and was first described by the French doc-tor Etienne Fallot (1850-1911).• In ventricular septal defect, an opening between thetwo ventricles allows blood to shunt between them. De-pending on the anomaly’s size, spontaneous closure mayoccur (if small); if closure doesn’t occur, right- and left-sided heart failure and cyanosis occur.

Degenerative heart conditionsDegenerative heart disease is a progressive deteriora-tion of heart structures, tissue, and function. Some formsof degenerative heart disease are listed here:• Coronary artery disease (CAD) occurs when the ar-teries that serve the heart are obstructed or narrowed.The most common cause of CAD is atherosclerosis (de-posits of plaque inside the arteries). In addition to slow-ing blood flow, atherosclerosis damages and deforms themuscular arterial walls, increasing the risk of aneurysm.(See Atherosclerosis: The hard facts.)• In dilated cardiomyopathy, the heart dilates andtakes on a round shape as a result of extensively dam-aged heart muscle fibers.• Heart failure develops when the heart can’t effective-ly pump blood and becomes congested with extra fluid.• Hypertension refers to blood pressure that’s abovenormal values, typically greater than 140/90 mm Hg (or130/80 mm Hg in patients with diabetes or chronic kidneyfailure). A patient with a systolic blood pressure of 120 to139 and a diastolic pressure of 80 to 89 is considered pre-hypertensive.• Hypertrophic cardiomyopathy is a primary diseaseof cardiac muscle that’s characterized by disproportion-ate thickening of the interventricular septum and ventric-ular walls.• In an MI, commonly called a heart attack, reducedblood flow through one of the coronary arteries results inmyocardial ischemia (lack of blood supply) and necro-sis (tissue death).


Atherosclerosis:The hard facts

Breaking apart the wordatherosclerosis is easy.The Greek word athere

means soft, fatty, andgruel-like, and scler-

means hard. Put them to-gether and these termsaccurately describe thematerial deposited onthe inner lining of anartery that causes ather-osclerosis.


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• Restrictive cardiomyopathy is characterized by re-stricted ventricular filling (the result of left ventricularhypertrophy) and endocardial fibrosis.

Inflammatory heart diseaseTypes of heart inflammation, caused by injury or tissuedestruction, are described below:• Endocarditis is a bacterial or fungal infection of theheart valves or endocardium.• Myocarditis is an inflammation of the heart musclethat can be acute or long term.• Pericarditis is an inflammation of the pericardium, theprotective sac that encloses the heart. In constrictivepericarditis, the pericardium thickens and constricts theheart’s ability to pump, causing heart failure.• Rheumatic fever is a childhood disease caused bystreptococcal bacteria.

Vascular disordersThe following terms are associated with disorders of thevascular system:• Arterial occlusive disease is caused by obstructionof the lumen of the arteries, causing ischemia (de-creased blood flow and tissue hypoxia), most commonlyto the legs and feet.• Raynaud’s disease is an arteriospastic disease charac-terized by episodic vasospasm in the arteries or arteriolesthat’s precipitated by cold or stress.• Thrombophlebitis is an acute condition characterizedby inflammation and thrombus formation. Thrombo-phlebitis may occur in deep (intramuscular) or superfi-cial (subcutaneous) veins. Deep vein thrombophlebitiscan affect small veins, such as the soleal venus sinuses,or large veins such as the venae cavae.

Weak wallsAn aneurysm (a weakening of the walls of a vessel) oc-curs most commonly in the aorta but can happen in anyvessel and can take a number of different forms:• Abdominal aortic aneurysm, an abnormal dilation inthe arterial wall, most commonly occurs in the aorta be-low the renal arteries and above the iliac branches.

133DISORDERS

Inflammation

can be pretty

serious

business.

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• Aortic dissection is usually caused by high bloodpressure that forces the layers of the aortic walls to sepa-rate, creating a false lumen. Acute aortic dissection ischaracterized by sharp, tearing pain in the chest or back.• Thoracic aortic aneurysm is an abnormal wideningof the ascending, transcending, or descending part of theaorta above the diaphragm.

Aneurysms may be saccular (unilateral pouchlikebulge with a narrow neck), fusiform (spindle-shapedbulge encompassing the entire diameter of the vessel), orfalse (a pulsating hematoma resulting from trauma andoften mistaken for an abdominal aneurysm).

Valvular disordersWhen a valve fails, several different disorders can result,including stenosis and cardiac insufficiency.

The thick of itStenosis, a thickening of valvular tissue that results innarrow valve openings, can occur as one of three types:• Aortic stenosis, or narrowing of the aortic valve, cre-ates elevated pressure in the left ventricle.• Mitral stenosis, or narrowing of the mitral valve, ob-structs blood flow from the left atrium to the left ventri-cle, causing enlargement of the left atrium as a form ofcompensation.• Tricuspid stenosis obstructs blood flow from theright atrium to the right ventricle, causing the rightatrium to enlarge.

Insufficient fundsFour types of coronary insufficiency, the incompleteclosure of a valve, may also result:• Aortic insufficiency occurs when blood leaks backinto the left ventricle during the diastolic phase of theheartbeat, when the ventricles rest. The left ventricle en-larges and fluid builds up in the left atrium and the pul-monary system, leading to left-sided heart failure and pul-monary edema.• Mitral valve insufficiency occurs when blood fromthe left ventricle flows back into the left atrium, causingthe left atrium and ventricle to enlarge as compensationfor the heart’s decreased efficiency.


Valves can

be tricky!

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• Pulmonary valve insufficiency allows blood from thepulmonary artery to flow back into the right ventricleduring diastole.• In tricuspid insufficiency, blood flows back into theright atrium as the ventricles contract during systole.This reduces blood flow to the lungs and the left side ofthe heart and also decreases cardiac output.

Treatments

Cardiovascular disorders can be treated with drug ther-apy and surgery. Here’s a list of treatments and surgicalinterventions.

Drug therapyThese drugs may be used alone or in combination to treatcardiovascular disorders:• Adrenergics help treat serious hypotension.• Angiotensin-converting enzyme inhibitors are usedto treat hypertension and heart failure. They’re also usedto prevent future heart attcks.• Antianginal drugs treat or prevent cardiac pain.• Antiarrhythmics can prevent or treat arrhythmias.• Antihypertensives reduce cardiac output or decreaseperipheral vascular resistance to lower blood pressure.• Beta-adrenergic blockers are used to treat hyper-tension, angina, and heart failure.• Calcium channel blockers lower blood pressure andreduce the workload of the heart.• Cardiac glycosides are used to manage heart failureand certain types of arrhythmias.• Diuretics treat edema and hypertension by reducingcirculating fluid volume.• Thrombolytic therapy is used to dissolve clots.

SurgeryHere are some common surgical procedures used to cor-rect functional or structural heart problems:• Ablation is a procedure in which small, selected areasof the heart are destroyed to treat refractive tachycardia.

135TREATMENTS

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• Cardiac conduction surgery is done to treat atrialand ventricular tachycardias that can’t be controlled bydrug therapy or pacing.• Coronary artery bypass graft (CABG) surgery re-stores circulation when occluded coronary arteries pre-vent normal blood flow to the heart muscle. Occluded ar-teries are replaced with segments (grafts) from other ves-sels, most commonly the saphenous veins in the leg. Thiscan also be accomplished using a less invasive procedurecalled minimally invasive surgery. (See Cabbage isslang for CABG.)• Heart transplantation is a complex and controversialprocedure that involves replacing a diseased heart withthe healthy heart of a brain-dead donor.

Other treatments• Advanced cardiac life support involves the recogni-tion and treatment of acute cardiac emergencies, such ascardiac arrest, MI, and lethal arrhythmias.• Cardiopulmonary resuscitation is a basic life sup-port procedure performed on victims with cardiac arrest.• In defibrillation, an electric shock is used to termi-nate tachyarrhythmias.• An implantable cardioverter-defibrillator is an im-planted device that senses an arrhythmia and delivers anelectric shock to the myocardium, terminating the ar-rhythmia.• In intra-aortic balloon counterpulsation, used totemporarily reduce the left ventricle’s workload, an inflat-able balloon is inserted into the patient’s aorta. A pumpinflates the balloon while the ventricle rests and deflatesit at the start of each ventricular contraction. The inflatedballoon forces blood into the major arteries and reducesthe heart’s workload during contraction.• During laser-enhanced angioplasty, a doctor threadsa laser-containing catheter into the diseased artery. Rapidlaser pulses destroy the occlusion, and balloon angioplas-ty is performed later.• Pacemakers use electrical impulses to regulate car-diac rhythm. Pacemakers can be permanent, transve-nous, or transcutaneous.• Percutaneous transluminal coronary angioplasty(PTCA) is a nonsurgical alternative to CABG surgery.


Cabbage isslang for CABG

You may hear coronary

artery bypass surgery

referred to as cabbage.

Cabbage is slang forCABG, the abbreviationfor coronary artery by-pass graft. A triple cab-

bage is a three-vesselbypass procedure.

The realworld

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During this procedure, a guide catheter is threaded intothe coronary artery and positioned at the site of an steno-sis or occlusion. A doctor then inserts a small ballooncatheter through the guide catheter and positions the bal-loon inside the stenosis or occlusion. When the balloon isinflated, the coronary artery dilates and blood flow im-proves. (See Profiling PTCA.)• In some cases, a stent (tube or coil) is placed insidethe artery to support it and prevent reocclusion.• Synchronized cardioversion delivers an electriccharge to the myocardium at the peak of the R wave onthe ECG. This electrical charge stops the arrhythmia andallows the SA node to resume control.• Valve replacement surgery is used to replace faultyvalves in patients with severe symptoms who don’t re-spond to more conservative approaches. Bothmechanical and biological prosthetic valvesare commonly used.• A ventricular assist device is a temporary,life-sustaining treatment that diverts systemicblood flow from a diseased ventricle into acentrifugal pump.

137TREATMENTS

The term percutaneous transluminal coronary angioplasty is abbreviated PTCA.


Profiling PTCA

First half

The first component of the term, per-,

means through and cutaneous meansthe skin—so through the skin. The prefixtrans- means through; luminal refers toa blood vessel.

Second half

Coronary refers to the two arteries andtheir branches that stem from the aorta,which supply the heart tissue withblood. Angio- also means blood vesseland plasty is a suffix that means the re-pair of.

All together

So PTCA really means repair of a coro-nary blood vessel by way of the skin andanother blood vessel.

There sure

are a lot of

ways to get

me back in

the game.

845506.qxd 8/19/08 5:05 PM Page 137


Across

5. Return blood to the heart7. Smallest blood vessels9. Hardening of the arteries10. Thin sac that protects the heart12. Rapid heartbeat

13. Chest pain14. Blue-colored skin15. Lower chamber of the heart16. Carry blood away from theheart17. Upper chamber of the heart

Down

1. Lining of the heart’s chambers2. High blood pressure3. Slow heartbeat4. Word for abnormal paleness6. When the heart contracts

8. Deviation from normal rhythm11. Heart muscle


This type of

exercise is hard

work but mental

exercise can be

pretty tough,

too!

Vocabulary builders

At a crossroadsHere’s a puzzle that’s sure to tug at your heartstrings. Goodluck!

1 2 3 4 5 6

7

8

9

10

11

12

13

14

15

16

17

845506.qxd 8/19/08 5:05 PM Page 138



Finish lineThe Latin word cardium, which means heart, appears in almost all medical terminologyrelating to that structure. Fill in each of the blanks below with the prefix, suffix, or rootthat finishes the heart-related term.

1. A heart doctor is a cardi ______________

2. A patient with ______________ cardia has a slow heartbeat.

3. Another name for the condition of an enlarged heart is cardio ______________

4. Inflammation of the heart muscles due to infection is called card ______________

5. The ______________ cardio ______________ is a device for recording the electrical activity ofthe myocardium.


1.

2.

3.

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Match gameMatch the choices below to the appropriate answers.

Clues

1. Add the prefix that means rapid to the cor-rect form of the root cardium. ________

2. Add the prefix that means around and the af-fix that means to puncture to the correct formof the root cardium. __________

3. Add the prefix that means muscle to the cor-rect form of the root cardium. _________

4. Add the suffix that refers to the lungs to thecorrect form of the root cardium. _________

5. Add the prefix that means within to the cor-rect form of the root cardium. _________

6. Add the prefix that means on to the correctform of the root cardium. _________

7. Add the prefix that means vessel and thesuffix that means to write to the correct formof the root cardium. _________

Choices

A. Pericardiocentesis

B. Tachycardia

C. Cardiopulmonary

D. Myocardial

E. Epicardium

F. Angiocardiography

G. Endocardium

Add muscle

to cardium?

You’ve got it!

845506.qxd 8/19/08 5:05 PM Page 140




1. ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____

2. ____ ____ ____ ____ ____ ____ ____ ____ ____

3. ____ ____ ____ ____ ____ ____ ____ ____

4. ____ ____ ____ ____ ____ ____ ____ ____

5. ____ ____ ____ ____ ____ ____

1. Heart doctor2. An artery to the lungs3. Means near the top4. Consists of ventricular filling and atrial contraction5. Pain resulting from an inadequate supply of oxygen

What’s it

called when a

person has

the “blues?”

845506.qxd 8/19/08 5:05 PM Page 141


1. B; 2. A; 3. D; 4. C; 5. G; 6. E; 7. F

Match game

1. Diuretic; 2. Thrombophlebitis; 3. Sinoatrial

O see, can you say?

1. Cardiologist; 2. Pulmonary; 3. Superior; 4. Diastole; 5. AnginaAnswer to puzzle—Cyanosis

Talking in circles

At a crossroads

Answers

1. Ologist; 2. Brady; 3. Megaly; 4. Itis; 5. Electro, graph

Finish line

WOW!

That wasn’t

easy!

1E

2H

3B

4P

5V E I N

6S

N Y R A Y

D P7C A P I L L A R I E S

O E8A D L T

C R R Y O O9A R T E R I O S C L E R O S I S L

R E H A E

D N Y10P E R I C A R D I U M

I S T D

U I H I11M

M O M12T A C H Y C A R D I A

13A N G I N A O

A14C Y A N O S I S

A15V E N T R I C L E

D16A R T E R I E S

U17A T R I U M

845506.qxd 8/19/08 5:05 PM Page 142

Respiratory structure and function

The respiratory system consists of the upper and lowerrespiratory tracts and the thoracic cage. In addition tomaintaining the exchange of oxygen (O2) and carbondioxide (CO2) in the lungs and tissues, the respiratorysystem helps regulate the body’s acid-base balance. (SeePronouncing key respiratory system terms, page 144.)

Upper respiratory tractThe upper respiratory tract consists primarily of thenose, mouth, nasopharynx, oropharynx, laryngopharynx,and larynx. Besides warming and humidifying inhaled air,these structures enable taste, smell, and the chewing andswallowing of food. (See Structures of the respiratorysystem, page 145.)

NoseAir enters the respiratory tract through the mouth andnares (nostrils). In the nares, small hairs filter out dust

7

Health assessmentRespiratory system

Just the facts


♦ terminology related to the structure and function ofthe respiratory system

♦ terminology needed for physical examination of therespiratory system

♦ tests that help diagnose respiratory disorders

♦ common respiratory system disorders and theirtreatments.

845507.qxd 8/19/08 7:16 PM Page 143

and large foreign particles. Air then passes into the twonasal passages, which are separated by the septum.Cartilage forms the anterior walls of the nasal passages.

HumidifiersBony structures, conchae (singular: concha), form theposterior walls of the nasal passages. The conchae warmand humidify air before it passes into the pharynx (plur-al: pharynges) or throat, which serves as a passagewayfor the digestive and respiratory tracts.

PharynxThe pharynx consists of three sections:

The nasopharynx extends from the posterior naresto the soft palate.

The oropharynx extends from the soft palate to theupper portion of the epiglottis.

The laryngopharynx extends to the esophagus andlarynx. (See The three pharynges.)

144RESPIRATORY SYSTEM

Below is a list of key terms related to the respiratory system,along with the correct ways to pronounce them.


Pronouncing key respiratorysystem terms

Alveoli

Atelectasis

Bronchioles

Conchae

Cor pulmonale

Oropharynx

Sarcoidosis

AL-VEE-OH-LEYE

AHT-UH-LEHK-TAY-SIS

BRONG-KEE-OHLZ

KON-KEE

KOR-PULL-MAH-NAL-LEE

OR-OH-FAR-INKS

SAHR-KOY-DOH-SIS

The threepharynges

Notice that the words forthe three parts of thepharynx are all connect-ed by the common rootpharynx, which is Greekfor throat. Nasopharynx

uses the word for nose,naso, and the root phar-

ynx to describe the up-per portion of the phar-ynx. Oropharynx usesthe Latin word for mouth,or, from which we alsoget orifice. Laryngophar-

ynx adds laryngo, a formof larynx that’s usedwhen it’s combined withanother word.


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LarynxThe larynx, which contains the vocal cords, connectsthe pharynx with the trachea. (See Learn to say larynx,page 146.)

145RESPIRATORY STRUCTURE AND FUNCTION

This illustration shows the structures of the respiratory system, which include the organs responsible for external respiration.


Structures of the respiratory system

Sinus cavities

Nasopharynx

Oropharynx

Laryngopharynx

Esophagus(EE-SOF-UH-GUHS)

Carina(KAH-REYE-NUH)

Mediastinum(MEE-DEE-AS-TEYE-NUHM)

Nasal conchae

Naris (NAY-RIS)

Epiglottis(EP-UH-GLOT-is)

Trachea(TRAY-KEE-UH)

Left primary (mainstem) bronchus

Left secondary (lobar) bronchus

Bronchiole

Alveolus(AL-VEE-OH-LUHS)

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Speaking of the voice boxThe larynx is also called the voice box. It’s the main or-gan of speech. Air passing through the glottis—a slitlikeopening between the vocal cords—causes vibration ofthe cords during expiration, creating the sound of thevoice. The larynx is protected during swallowing by theepiglottis, a flexible cartilage that bends reflexively toclose the larynx to swallowed substances.

Lower respiratory tractThe lower respiratory tract is contained within thethoracic cavity and consists of the trachea, bronchi,and lungs. This space within the chest wall is boundedbelow by the diaphragm, above by the scalene musclesand fasciae of the neck, and around the circumference bythe ribs, intercostal muscles, vertebrae, sternum, and lig-aments.

TracheaThe tubular trachea, also called the windpipe, lies halfin the neck and half in the thorax. C-shaped cartilagerings reinforce and protect the trachea, preventing its col-lapse. The trachea is lined with a mucous membrane cov-ered with small hairlike projections called cilia. The ciliacontinuously sweep foreign material out of the breathingpassages toward the mouth.


It’s likely you’ll hear larynx (LAHR-INKS) pronounced LAHR-NIKS,with the sounds of the L and the N reversed. Although this rever-sal of sounds, called metathesis, is a common mix-up in all lan-guages, you may save yourself some embarrassment if you sayLAHR-INKS.


Learn to say larynx

Epiglottis…let’s

see. The prefix epi-

comes from Greek,

meaning upon.

Glottis comes from

the Greek word

glossa, which means

tongue.

845507.qxd 8/19/08 7:16 PM Page 146

BronchiThe trachea branches at the carina (also known as thetracheal bifurcation) into two smaller airways, the leftand right mainstem bronchi (primary bronchi). (See Ca-reening with the carina.)

The right mainstem bronchus—shorter, wider, andmore vertical than the left—supplies air to the right lung;the left mainstem bronchus delivers air to the left lung.

A way inThe mainstem bronchi—along with blood vessels, nerves,and lymphatics—enter the pleural cavity (the space be-tween the visceral and parietal pleurae) at the hilum. Lo-cated behind the heart, the hilum is a slit on the lungs’medial surface where nerves, lymphatic ducts, and bloodvessels enter and leave the lungs. In the lung, the main-stem bronchi divide into five lobar bronchi (secondarybronchi), so called because they enter into the lobes ofthe lung, one for each of the three lobes of the right lungand two for the left.

First branches, now twigsThe lobar bronchi divide into smaller and smaller branch-es, until they become bronchioles. Each bronchiolebranches into a lobule. The lobule includes terminalbronchioles and the acinus—the chief respiratory unitfor gas exchange. (See Looking at a lobule, page 148.)


It’s more accurate to say the carina of the trachea because acarina (KAH-REYE-NAH) can be any keel-shaped or ridge-shaped anatomic part. The word derives from Latin,meaning hull or keel of a ship, and was pronouncedKAH-REE-NAH. This is still the word carina’s sec-ondary pronunciation, and it’s the pronunciation forthe verb careen, which is also derived from carina.


Careening with the carina

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Ducts and sacsWithin the acinus, terminal bronchioles branch into yetsmaller respiratory bronchioles. The respiratory bron-chioles feed directly into alveoli at sites along their walls.The respiratory bronchioles eventually become alveolarducts, which terminate in clusters of capillary-swathedalveoli called alveolar sacs.

Fruit of the vineThe walls of the ducts contain alveoli (singular: alveo-lus), grapelike clusters where O2 is exchanged for CO2.

Capillary networkSurrounded by networks of tiny blood vessels called cap-illaries, alveoli have thin walls through which gas ex-change occurs. The average pair of lungs has about 300million alveoli.


Looking at a lobule

As illustrated below, each lobule contains terminal bronchiolesand the acinus, which consists of respiratory bronchioles andalveolar sacs.

Terminalbronchioles

Respiratorybronchioles

Alveolar duct

Alveolus

Alveolar sac

Acinus

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LungsThe cone-shaped lungs differ slightly from one another.The right lung is shorter, broader, and larger than the left.The right lung has three lobes and handles 55% of gas ex-change. The left lung has only two lobes; it shares the leftside of the thoracic cavity with the heart. Each lung’sconcave base rests on the diaphragm. The apex (ex-treme top) of each lung extends about 1⁄3� (1 cm) abovethe first rib. (See Studying the lungs.)

Remember the membraneThe pleura is the membrane that totally encloses thelungs. It’s composed of a visceral layer and parietal layer.The visceral pleura hugs the entire lung surface, includ-ing the areas between the lobes. The parietal pleura ex-tends from the roots of the lungs and covers the sides ofthe pericardium to the chest wall and backward to thespine.

Fluid spaceThe pleural cavity—the tiny area between the visceraland parietal pleural layers—contains a thin film ofserous fluid. This fluid has two functions:

It lubricates the pleural surfaces so that they slidesmoothly against each other during respiration.

It creates a bond between the layers that causes thelungs to move within the chest wall during breathing.

In the middleThe mediastinum (the space between the lungs)contains the• heart and pericardium• thoracic aorta• pulmonary artery and veins• venae cavae and azygos veins• thymus, lymph nodes, and lymphatic vessels• trachea, esophagus, and thoracic duct• vagus, cardiac, and phrenic nerves.

Thoracic cageSeveral structures support and protect the lungs and aidin respiration. Composed of bone and cartilage, the tho-


Studying thelungs

Pulmonology, whichcomes from the Latinword pulmo, meaninglung, and the suffix -ology, meaning thestudy of, is the sciencethat studies the lungs.


See the space

between my lobes?

It’s called the

mediastinum.

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racic cage supports and protects the lungs and permitsthem to expand and contract. The anterior portion of thethoracic cage consists of the manubrium, sternum,xiphoid process, and 10 pairs of ribs. The posterior por-tion of the thoracic cage consists of the vertebral col-umn, the same 10 pairs of ribs, and 2 pairs of floatingribs.

RespirationEffective respiration consists of a gas exchange in thelungs, called external respiration, and a gas exchangein the tissues, called internal respiration. External res-piration occurs through three processes:

diffusion—gas movement through a semipermeablemembrane from an area of greater concentration to oneof lesser concentration (internal respiration occurs onlythrough diffusion)

pulmonary perfusion—blood flow from the rightside of the heart, through the pulmonary circulation, andinto the left side of the heart

ventilation—gas distribution into and out of thepulmonary airways.

Air supplyAdequate ventilation depends on the proper working ofthe nervous, musculoskeletal, and respiratory systems toaccomplish the necessary changes in lung pressure. (SeeVentilation and perfusion.)

At the baseThe most important muscle for respiration is the dia-phragm, a dome-shaped organ composed of muscle andmembrane that separates the thoracic and abdominalcavities. During inspiration, the diaphragm moves downand expands the volume of the thoracic cavity; during ex-piration, it moves up, reducing the volume.

Respiration chemistryThe body depends on a delicate balance between acidsand bases to sustain life. The lungs help maintain this bal-


Adequate

ventilation depends

on the proper working

of the nervous,

musculoskeletal, and

respiratory systems.

845507.qxd 8/19/08 7:16 PM Page 150

ance by altering the rate and depth of respiration in re-sponse to changes in blood pH.

Acids and basesTo understand acid-base balance, you need to know threeimportant terms:• acids, which are substances that dissociate (becomefragmented, or separate) in solution, releasing hydrogenions (carbonic acid is an example of an acid found in thebody)


Please

don’t shunt

me out!

Effective gas exchange depends on a stable relationship be-tween ventilation and perfusion. You’ll see this called the V/Q

ratio. A V/Q mismatch accounts for many respiratory disordersand can affect all body systems. The following types of mismatchcan occur.

Need more oxygen

Inadequate ventilation, also called a shunt, occurs when pul-monary circulation is adequate but not enough oxygen (O2) isavailable in the lungs. As a result, a portion of the blood flowingthrough the pulmonary capillaries doesn’t receive O2. Perfusionwithout ventilation usually results from airway obstruction, par-ticularly that caused by acute diseases, such as atelectasis andpneumonia, which produce a low V ratio.

Need more blood

Inadequate perfusion, also called dead-space ventilation, pro-duces a high V ratio. Ventilation is normal, but blood flow inthe pulmonary capillaries isn’t adequate. Narrowed capillaries,decreased cardiac output, and pulmonary emboli (blood clots)commonly cause this condition.

Need both!

Inadequate ventilation and perfusion, also referred to as a silent

unit, describes a lack of O2 in the lungs (ventilation) and in thepulmonary circulation (perfusion). When entire sections of thelung become “silent,” the body compensates by delivering bloodflow to better ventilated lung areas. Chronic alveolar collapseand pulmonary emboli can create silent units.

Now I get it!

Ventilation and perfusion

. .. .

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• bases, such as bicarbonate, which are substances thatdissociate to yield hydroxide ions in aqueous solutions• pH, which represents the relative concentration of hy-drogen ions in a solution compared to the hydrogen ionconcentration of a standard solution (normally, blood pHlevel measures 7.35 to 7.45).

A solution with more base than acid contains fewerhydrogen ions, resulting in a higher pH. A solution thatcontains more acid than base has more hydrogen ions, re-sulting in a lower pH.

Staying in balanceA deviation in pH level can compromise essential bodyfunctions, including electrolyte balance, the activity ofcritical enzymes, muscle contraction, and basic cellularfunction. The body normally maintains a pH level withina narrow range by carefully balancing acidic and alkalineelements. When one aspect of that balancing act breaksdown, the body can’t maintain a healthy pH level as easi-ly, and problems arise.

Regulating methodThe lungs use hyperventilation (increased ventilation)or hypoventilation (decreased ventilation) to regulateblood levels of CO2, a gas that combines with water toform carbonic acid. Increased carbonic acid levels leadto a decrease in pH level.

Eliminate CO2, increase pHChemoreceptors in the brain sense pH changes and varythe rate and depth of breathing to compensate. Breathingfaster or more deeply eliminates more CO2 from thelungs. The more CO2 is expelled, the less carbonic acid ismade and, as a result, the pH level rises. (See CO2 andhyperventilation.)

Increase CO2, reduce pHThe body normalizes such a change in pH by slowing therate or decreasing the depth of breathing, thus reducingCO2 excretion. CO2 and pH move in opposite directions.If pH rises, CO2 falls, and vice versa.


Think of it

this way. More

base elevates

the pH.

845507.qxd 8/19/08 7:16 PM Page 152


Examining a patient’s respiratory status requires observa-tion, palpation, and the ability to identify breath sounds.(See Name that breath sound, page 154.) Before you canperform a complete physical examination you need to un-derstand these essential respiratory terms:• anoxia—absence or near absence of O2 in inhaled air,body tissues, or arterial blood• auscultation—assessment step; listening, either di-rectly or with a stethoscope, for sounds within the body• bronchospasm—sudden, forceful, involuntary con-traction of the smooth muscle of the bronchi, causingnarrowing and obstruction of the airway• chest retraction—visible depression of soft tissues ofthe chest between and around the cartilaginous and bonyribs, occurring with increased inspiratory effort• clubbing—enlargement of the soft tissues of the distalphalanges that occurs in children with congenital heartdisease and in older children and adults with long-stand-ing pulmonary disease• cyanosis—bluish discoloration of the skin and mucousmembranes resulting from an excessive amount of de-oxygenated hemoglobin in the blood• dyspnea—shortness of breath, difficulty breathing, orlabored breathing


CO2 and hyperventilation

When a patient’s respiratoryrate increases, carbon diox-ide (CO2) is “blown off” andthe CO2 level drops.

Respiratory rate

CO2

845507.qxd 8/19/08 7:16 PM Page 153

• expectoration—ejection of mucus from the tracheaand lungs by coughing and spitting• expiration—act of exhaling air• hemoptysis—coughing or spitting up blood• inspiration—act of inhaling air• orthopnea—discomfort in breathing except in an up-right position (see Three-pillow orthopnea)• palpation—assessment step; feeling the body surfacewith the hand


Name that breath sound

Listed below are normal and abnormal breath sounds, including their characteristics and wherethey’re heard.Normal sounds

Normal breath sounds reflect air movementthrough the tracheobronchial tree. Normalbreath sounds are described below:• Tracheal breath sounds are harsh, discontin-uous sounds heard over the trachea. They oc-cur when a patient inhales or exhales.• Bronchial breath sounds are loud, high-pitched sounds normally heard below the tra-chea at the manubrium. They’re discontinuousand loudest when the patient exhales.• Vesicular breath sounds are heard in front ofthe chest, on both sides, and in back. They’relonger and louder during inspiration than expi-ration and can be heard in the peripheral lungfields.• Bronchovesicular breath sounds can beauscultated over the mainstem bronchi andbetween the shoulder blades. They have a soft,medium-pitched, breezy sound. They’re lower-pitched than bronchial sounds, but higher-pitched than vesicular sounds.

Abnormal sounds

Abnormal breath sounds, also called adventi-

tious sounds, help diagnose many respiratorydisorders.• Crackles are crackling sounds, like hairs be-ing rubbed together, usually heard first over the

lung bases during inspiration. Crackles are fur-ther classified by pitch as high (fine), medium,

or low (coarse). Crackles are sometimes calledrales.

• Rhonchi are loud, coarse, low-pitched bub-bling sounds heard primarily when a patientexhales, although they may also be heardwhen the patient inhales. Rhonchi are some-times called sonorous wheezes. You’ll auscul-tate rhonchi over the central airways.• Wheezes are high-pitched, musical soundsthat may occur during inspiration but occurpredominantly during expiration. Wheezes areheard over the large bronchi.• Pleural friction rubs are coarse, low-pitchedabnormal breath sounds heard at the antero-lateral chest wall (in front, near the ribs) during inspiration and expiration. A friction rub soundslike pieces of sandpaper being rubbed together.• Grunting respirations refer to a coarse,grunting noise heard during expiration.• Stridor is a crowing sound heard during in-spiration that is caused by air whistling as itpasses through swollen upper airways.• Decreased breath sounds describes abnor-mally diminished sounds in areas of the lung.• Absent breath sounds refers to a lack ofsound over areas of the lungs that normallyhave breath sounds. Three-pillow

orthopnea

You may hear the termthree-pillow orthopnea

used to describe a pa-tient’s sleeping habits.This means the patientrequires three pillows tobreathe comfortablywhile sleeping.

The realworld

Abnormal breath

sounds are also called

adventitious sounds.

It may help you to

think of the word

adventure, because

these sounds are out

of the ordinary.


845507.qxd 8/19/08 7:16 PM Page 154

C5INCREDIBLY EASY MINIGUIDE: THE LUNGS

Incredibly Easy miniguide: The lungs

The lower respiratory tract, which is contained within the thoracic cavity, consists of the trachea, bronchi, and lungs. The diaphragm isa dome-shaped organ that plays a vital part in respiration.

The trachea, alsocalled the windpipe,

branches into the right andleft mainstem bronchi.

Without the

diaphragm, I wouldn’t

have enough room to

breathe.

The right

mainstem

bronchus isshorter, wider, andmore vertical than

the left anddelivers air to the

right lung.

The left mainstem

bronchus delivers airto the left lung.

During inspiration,the diaphragm moves

down; during expiration,it moves up.

8455CP2.qxd 8/19/08 8:01 PM Page C5



The right lung isshorter, broader, and larger

than the left. It has threelobes and handles 55% of

gas exchange.

The left lung

has only twolobes.

Bronchopulmonary segments (anterior view)

The right lung is separated into the superior, middle, and inferior lobes by the horizontal and oblique fissures. The left lung is separatedinto the upper and lower lobes by the oblique fissure. A cavity between the lobes (cardiac notch) accommodates the heart.

Wow! My right side is

larger and has one more

lobe than my left side.

No wonder it handles

more of the work.

8455CP2.qxd 8/19/08 8:01 PM Page C6

C7INCREDIBLY EASY MINIGUIDE: THE LUNGS


The alveolar sacsare the center of gas

exchange.

The lungs in a typical adult contain approximately 300 million alveoili, which are surrounded by an extensive network of capillaries.

Hmmm…

I wonder what

kind of exchange

rate they get

here.

The mainstembronchi eventually divide

into the lobar bronchi,

which further divide intobronchioles.

The alveolar ductterminates in clusters

of alveoli calledalveolar sacs.

Intrapulmonary airway

The lungs in a typical adult contain about 300 million alveoli, which are surrounded by an extensive network of capillaries.

The alveolar sacs

are the centers of gasexchange.


8455CP2.qxd 8/19/08 8:01 PM Page C7



Oxygen (O2) and carbon dioxide (CO2) diffusion among the alveoli, blood, and tissues depends on the concentrations and pressuresof these gases.

Alveolus cross section

Thanks to the

lungs, I can get the

oxygen I need to keep

the body going.Carbon dioxide diffusesfrom the blood into the

air and is exhaled.

In the alveoli,

oxygen from inhaled airdiffuses into the blood.

8455CP2.qxd 8/19/08 8:01 PM Page C8

• percussion—assessment step; striking a part of thebody with short, sharp blows of the fingers to detectchanges in sound or mobilize lung secretions• respiratory rate—number of breaths per minute• shunting—condition in which blood moves from thevenous circulation to the arterial circulation without par-ticipating in gas exchange, leading to hypoxemia• subcutaneous crepitus—soft, popping sound pro-duced by palpation or stroking of the skin; caused bybubbles of air or other gases such as CO2 trapped in thesubcutaneous tissue; may occur with pneumothorax• tactile fremitus—vibration in the chest wall that maybe felt when a hand is applied to the thorax while the pa-tient is speaking.

Respiratory patternsThe following terms describe different respiratory pat-terns:• apnea—absence of breathing (may be periodic)• apneustic breathing—prolonged, gasping inspira-tions followed by extremely short, inefficient expirations• Biot’s respirations—irregular periods of apnea alter-nating with periods of four or five breaths having thesame depth• bradypnea—unusually slow, regular respirations• Cheyne-Stokes respirations—alternating periods ofapnea and deep, rapid breathing (see Cheyne-Stokes)• eupnea—normal respiratory rate and rhythm• Kussmaul’s respirations—faster and deeper respira-tions than normal, without pauses• tachypnea—abnormally rapid respiratory rate.

Diagnostic tests

Below are the names of some diagnostic tests for the res-piratory system and its associated disorders.

Ventilation testsVentilation tests, also called pulmonary function tests,include a series of measurements that evaluate the lungs’ventilatory function:

155DIAGNOSTIC TESTS

Cheyne-Stokes

Cheyne-Stokes respira-tions were named afterJohn Cheyne, a Scottishdoctor, and WilliamStokes, an Irish doctor.


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• diffusing capacity for carbon monoxide (DLCO)—amount of carbon monoxide diffused per minute acrossthe alveolar membrane• expiratory reserve volume (ERV)—volume of airthat can be exhaled after normal expiration is completed• forced expiratory volume (FEV)—volume of air ex-pired in the first, second, and third seconds of the forcedvital capacity test• forced vital capacity (FVC)—volume of air that canbe exhaled after maximum inspiration• functional residual capacity (FRC)—volume of airremaining in the lungs after normal expiration• inspiratory capacity (IC)—volume of air that can beinhaled after normal expiration• inspiratory reserve volume (IRV)—maximum vol-ume of air that can be inspired after normal inspiration iscomplete• maximum voluntary ventilation (MVV)—the great-est volume of air breathed per unit of time• minute volume (VE)—volume of air breathed perminute, calculated from the tidal volume• residual volume (RV)—volume of air that is alwaysin the lungs and can’t be exhaled (must be measured indi-rectly)• tidal volume (VT)—volume of air inhaled or exhaledduring normal breathing• total lung capacity (TLC)—volume of the lungs atpeak inspiration• vital capacity (VC)—maximum volume of air thatcan be exhaled after maximum inspiration.

Radiologic testsRadiologic tests, which use X-rays or electromagneticwaves to create images of interior structures, can be usedto diagnose respiratory problems:• Chest radiography, commonly known as chest X-ray,creates an image of the thorax to reveal abnormalities.• Magnetic resonance imaging (MRI) is a procedurein which the patient is placed in a magnetic field intowhich a radiofrequency beam is introduced. Resulting en-ergy changes are measured and computed, generating im-ages on a monitor. Cross-sectional images of the anatomycan be viewed in multiple planes.


I could paint you a

picture but radiologic

tests help you get a

good look at me.

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• Pulmonary angiography, also called pulmonaryarteriography, is the radiographic examination of thepulmonary circulation after injection of a radiopaquecontrast dye into the pulmonary artery or one of itsbranches.• Thoracic computed tomography (CT) scan pro-vides cross-sectional views of the chest by passing anX-ray beam from a computerized scanner through thebody at different angles. CT scanning may be done withor without an injected contrast dye.• Ventilation-perfusion scan combines two proce-dures to evaluate the lungs’ ventilation and perfusion.The ventilation scan is performed after the patient in-hales a mixture of air and radioactive gas that delineatesareas of the lung ventilated during respiration. The perfu-sion scan produces an image of pulmonary blood flow af-ter I.V. injection of a radioactive dye.

Other testsHere are other tests used to diagnose respiratory systemdisorders:• Arterial blood gas measurement provides levels ofO2 and CO2 in arterial blood to evaluate acid-base bal-ance and to assess and monitor a patient’s ventilation andoxygenation status. (See What a gas! and What arterialblood gases reveal, page 158.)• Bronchoscopy allows visual inspection of the tracheo-bronchial tree. (See Understanding bronchoscopy, page158.)• Culture and sensitivity tests help identify thecausative organism in bacterial, viral, or fungal infec-tions.• Pulse oximetry is a continuous noninvasive study ofarterial blood oxygen saturation using a probe or clip at-tached to a sensor site.• Sputum analysis is the examination of a sample of ex-pectorated material from the patient’s lungs.• In thoracentesis, a needle is used to puncture thechest and aspirate fluid from the parietal cavity for diag-nostic or therapeutic purposes.

157DIAGNOSTIC TESTS

What a gas!

In practice, you’ll com-monly hear arterial

blood gases referred toas ABGs, blood gases, orsimply gases—as in“Let’s draw somegases.”

The realworld

845507.qxd 8/19/08 7:16 PM Page 157

Disorders

The respiratory system is such a complex network thatmany things can go wrong. Here’s is a list of major respi-ratory disorders:• Acute bronchitis is an inflammation of the bronchiaccompanied by mucus production and subsequent ob-struction of airflow. Infectious agents, such as influenzavirus, streptococci, pneumococci, staphylococci, andHaemophilus organisms, can cause acute bronchitis.• Acute respiratory failure (ARF) is caused by thecardiac and pulmonary systems inadequately exchangingO2 and CO2 in the lungs.• Acute respiratory distress syndrome (ARDS) is aform of pulmonary edema that can quickly lead to acuterespiratory failure.• Asbestosis is caused by prolonged inhalation of as-bestos fibers, which become encased in the bronchiolesand alveolar walls in a proteinlike sheath.• Atelectasis is the collapse of lung tissue or incompleteexpansion of a lung caused by the absence of air in a por-


Understanding bronchoscopy

In bronchoscopy, a bronchoscope is used to examine the bronchi. This procedure is also used toobtain specimens or to remove foreign bodies.

What arterialblood gasesreveal

Arterial blood gas analy-sis helps to diagnose thefollowing disorders:• respiratory acidosis,

or excess carbon dioxide(CO2) retention, which istypically caused by hy-poventilation• respiratory alkalosis,

which occurs when toomuch CO2 is excreted(hyperventilation is theprimary cause)• metabolic acidosis,

which reflects elevatedacid levels and may becaused by loss of bicar-bonate, excess acid pro-duction, or a combina-tion of both• metabolic alkalosis,

which reflects elevatedbicarbonate levels, de-creased acid levels, orboth (prolonged vomitingand loss of potassiumcan deplete the body’sacid stores; overuse ofalkaline medicationssuch as antacids canproduce elevated bicar-bonate levels).

Bronchoscope

Trachea

Bronchus

845507.qxd 8/19/08 7:16 PM Page 158

tion of the lung or the entire lung. (See Expanding on at-electasis.)• Bronchiectasis is a condition marked by chronic ab-normal dilation of bronchi and destruction of bronchialwalls.• Chronic obstructive pulmonary disease (COPD)refers to a group of long-term pulmonary disordersmarked by resistance to air flow (hence the term ob-structive). Types of COPD include:– asthma—episodic airway obstruction caused by bron-chospasm, increased mucus secretion, and mucosal ede-ma; may be either extrinsic (atopic), a reaction to spe-cific external allergens, or intrinsic, a reaction to inter-nal, nonallergenic factors– chronic bronchitis—characterized by excessive mu-cus production with productive cough lasting at least 3months per year for 2 successive years; usually caused byprolonged exposure to bronchial irritants such as smok-ing, secondhand smoke, air pollution, dust, and toxicfumes– emphysema—abnormal, permanent enlargement of theacini that’s accompanied by destruction of the alveolarwalls. It occurs when alveolar gas is trapped and gas ex-change is compromised.• Cor pulmonale is a heart condition in which hyperten-sion of the pulmonary circulation leads to enlargement ofthe right ventricle.• Croup is a severe inflammation and obstruction of theupper airway that usually follows an upper respiratorytract infection. It’s a childhood disease characterized by asharp barklike cough.• Cystic fibrosis is a multisystem genetic disorder, a de-fect of the exocrine glands, causing tenacious mucus inthe lungs.• Empyema is a form of pleural effusion in which thefluid in the pleural space contains pus.• Epiglottiditis is an acute inflammation of the epiglot-tis that tends to cause airway obstruction.• Hemothorax is a collection of blood in the pleuralcavity.• Hypoxemia is a deficiency of O2 in the arterial bloodbut isn’t as severe as anoxia.• Hypoxia is a deficiency of O2 at a cellular level.

159DISORDERS

Expanding onatelectasis

Atelectasis derives fromthe Greek terms ateles,

meaning imperfect, andektasis, meaning expan-sion. It refers to the col-lapse of lung tissue or in-complete expansion of alung.


845507.qxd 8/19/08 7:16 PM Page 159

• Legionnaires’ disease is an acute, noncommu-nicable bronchopneumonia caused by an airbornebacillus.• Lung abscess is a lung infection accompaniedby pus accumulation and tissue destruction.• Pleural effusion is accumulation of fluid in theinterstitial and air spaces of the lung.• Pleurisy is an inflammation of the pleurae character-ized by dyspnea and stabbing pain, leading to restrictionof breathing.• Pneumonia is an acute infection of lung parenchymacommonly impairing gas exchange.• Pneumothorax is a collection of air in the pleural cav-ity that leads to partial or complete lung collapse. (SeePneuma: A breath of air.) Different types of pneumotho-rax include:– closed pneumothorax—condition in which air entersthe pleural space from within the lungs– open pneumothorax—condition in which atmospher-ic air flows directly into the pleural cavity– tension pneumothorax—condition in which air in thepleural space compresses the thoracic organs, possiblycausing mediastinal shift of organs and blood vessels,thus reducing blood flow to and from the heart.• Pulmonary edema is a common complication of car-diac disorders in which extravascular fluid accumulatesin the lung tissues and alveoli.• Pulmonary embolism occurs when a clot or foreignsubstance lodges in a pulmonary artery.• Pulmonary fibrosis is scar tissue formation in theconnective tissue of the lungs.• Pulmonary hypertension is any condition that in-creases resistance to blood flow in the pulmonary ves-sels. The most common cause is COPD.• Pulmonary infarction occurs when lung tissue is de-nied blood flow and dies.• Respiratory distress syndrome, also called hyalinemembrane disease, is the most common cause ofneonatal mortality. In respiratory distress syndrome, thepremature infant develops widespread alveolar collapse.• Sarcoidosis is a multisystem, granulomatous disorderthat characteristically produces enlarged lymph nodes,pulmonary infiltration, and skeletal, liver, eye, or skin le-sions.


Pneuma: Abreath of air

In English, the Pn- com-bination always indi-cates a word of Greekorigin, and the p isn’tpronounced. Pneuma,

the Greek word forbreath, spirit, or wind,has given rise to a num-ber of words. In medicalterminology it means airor lung. Thorax is aGreek word that meanschest. It makes sensethen that a pneumotho-

rax is a collection of airin the chest.


Don’t let the name fool

you. Tension pneumothoraxdoesn’t result from stress.

Instead, it occurs when air in

the pleural space compresses

the thoracic organs.

845507.qxd 8/19/08 7:16 PM Page 160

• Silicosis is a progressive disease characterized bynodular lesions that commonly progress to fibrosis.• Sudden infant death syndrome (SIDS), also knownas crib death, is the unexplained sudden death of ahealthy infant (younger than 1 year) during sleep. Al-though the cause is unknown, placing the infant on hisback to sleep has been shown to significantly decreasethe incidence of SIDS.• Tuberculosis is an infectious disease in which pul-monary infiltrates accumulate in the lungs, cavities devel-op, and masses of granulated tissue form. It may also in-fect other body organs and tissues.

Treatments

In this section, you’ll learn the devices, surgical interven-tions, and other treatments used to improve oxygenation.

Tools of the tradeThese are names of medical devices used to treat respira-tory disorders:• bronchoscope—used therapeutically to remove for-eign bodies and tenacious secretions from the tracheaand bronchi and to visualize the tissues• chest tube—a tube inserted through a thoracostomyinto the pleural space and used to remove blood, fluid, orair in cases of hemothorax, pleural effusion, pneumo-thorax, or acute empyema• endotracheal (ET) tube—a flexible catheter insertedinto the trachea via the mouth or nose and used to deliverO2 into the lungs and maintain a patent airway• nasal cannula—small tubes that deliver a variable,low-flow O2 supply through the nasal passages (see Alook at a nasal cannula)• nebulizer—a device that delivers a fine spray for in-halation of moisture or drug therapy• resuscitation bag—an inflatable device that can be at-tached to a facemask or directly to an ET or tracheos-tomy tube that’s designed to manually deliver O2 or roomair into the lungs• stethoscope—an instrument used for auscultation ofrespiratory, cardiac, arterial, and venous sounds consist-

161TREATMENTS

A look at anasal cannula

A nasal cannula deliversa low-flow oxygen sup-ply to the nasal pas-sages through small,plastic tubes, as shownin the illustration below.

845507.qxd 8/19/08 7:16 PM Page 161

ing of two earpieces connected by flexible tubing to a di-aphragm, which is placed against the patient’s body• tracheostomy tube—a tube inserted into the surgicalopening through the neck into the trachea, which is usedto relieve upper airway obstruction and aid breathing;may be used with a mechanical ventilator (see A look at atracheostomy tube)• Venturi mask—a device designed to deliver a high-flow, precise O2 mixture (see A look at a Venturi mask).


A look at a tracheostomy tube

A tracheostomy tube is used to re-lieve upper airway obstruction and toaid breathing. The tube can be madeof plastic or metal and comes in threevarieties: uncuffed, cuffed, and fenes-trated. A plastic-cuffed tracheostomytube is shown here.

A look at a Venturi mask

A Venturi mask is a devicedesigned to deliver a high-flow, precise mixture of oxy-gen and air.

Elastic head strap

Vent holes

Wide-bore tubing

845507.qxd 8/19/08 7:16 PM Page 162

SurgeryHere are the names of surgical procedures used to treatrespiratory disorders:• pneumonectomy—surgical removal of the lung• thoracentesis—a needle puncture of the chest per-formed to drain fluid from the parietal cavity; it may beperformed at the bedside or as an outpatient procedure• thoracostomy—the surgical creation of an opening inthe chest wall for the purpose of drainage• thoracotomy—a surgical incision in the chest wallmade to excise a lung or portions of it; thoracotomy canbe further classified in three ways:– lobectomy—the surgical excision of a lobe of a lung– segmental resection—surgical removal of one ormore of the lung’s segments (removes more functionaltissue than a lobectomy)– wedge resection—the surgical removal of a triangularsection of lung tissue• tracheotomy—a surgical opening in the trachea thatprovides an airway for intubated patients who need pro-longed mechanical ventilation; also used to help removelung secretions and bypass upper airway obstruction.

Ventilation therapiesVentilation therapy moves air in and out of a patient’slungs, but it doesn’t ensure adequate gas exchange.

Manual ventilationIn manual ventilation, a handheld resuscitation bag isused to deliver room air or O2 to the lungs of a patientwho can’t breathe spontaneously. (See Vent ’em, bag’em.)

Mechanical ventilationMechanical ventilators may supply negative or positivepressure. Negative pressure on the chest and lungs ex-pands them during inspiration and is used to treat neuro-muscular disorders. Positive pressure, the most common-ly used mechanical ventilation system, is used to treatrespiratory disorders.

163TREATMENTS

Vent ’em,bag ’em

The handheld resuscita-tion bag is commonly re-ferred to as an Ambu

bag. You may hear peo-ple refer to the processof using this device asbagging the patient. Forexample, “Disconnecthim from the ventilatorand bag him.” If a patientrequires a mechanicalventilator to assist withbreathing, you may hearpeople say that the pa-tient is on a vent.

The realworld

845507.qxd 8/19/08 7:16 PM Page 163

Be positiveThe positive-pressure system exerts positive pressureon the airway to inflate alveoli during inspiration. The in-spiratory cycles of these ventilators may vary in volume,pressure, or time. There are three inspiratory cycle types:• Pressure-cycled ventilation provides a continuousflow of O2 until a preset pressure is reached.• Time-cycled ventilation provides flow for a presetamount of time.• Volume-cycled ventilation delivers a preset volume ofair.

In the modeVentilation is provided through several ventilator modes:• Control mode completely controls the patient’s respi-ration, delivering a set tidal volume at a prescribed rate.• Assist mode allows the patient to initiate a breath andreceive a tidal volume from the machine.• Assist-control mode allows the patient to initiatebreathing, but a backup control delivers a preset numberof breaths at a set volume.• Continuous positive-airway pressure (CPAP)maintains positive pressure in the airways throughout theentire respiratory cycle.• In the positive end-expiratory pressure (PEEP)mode, positive pressure is applied during expiration.• Pressure support ventilation augments the patient’sspontaneous breath with a preset pressure. It doesn’t pro-vide the entire volume. The rate isn’t set by the machine;it’s set by the patient’s spontaneous efforts.• In synchronized intermittent mandatory ventila-tion (SIMV), a machine delivers a set number of specific-volume breaths. The patient can breathe on his own be-tween SIMV breaths at volumes that differ from those onthe machine. SIMV is commonly used as a weaning tool,conditioning the patient’s respiratory muscles.

Drug therapyDrug therapy for respiratory disorders includes:• antitussives to suppress cough• decongestants to relieve swelling in nasal passages• expectorants, which liquefy secretions to help re-move mucus


Memoryjogger

In this case,mad is good!

To remember the es-sentials of drug ther-apy for respiratorydisorders, think “MEMAD”:

Methylxanthineagents

Expectorants

Mucolytics

Antitussives

Decongestants

845507.qxd 8/19/08 7:16 PM Page 164

• methylxanthine agents to relax bronchial smoothmuscle in patients with asthma and to stimulate respira-tory drive in patients with bronchitis, emphysema, andapnea• mucolytics to enhance mucus removal.

Other therapiesHere are other therapies to treat respiratory disorders:• Aerosol treatments deliver drugs by way of a nebuliz-er, which turns liquid into a spray the patient breathes.• Deep breathing loosens secretions and opens airways.• Oxygen therapy is delivered by a nasal cannula,catheter, mask, or transtracheal catheter; it prevents hy-poxemia and eases the patient’s breathing.• Postural drainage uses gravity to help move secre-tions from the lungs and bronchi into the trachea to becoughed up.• Percussion involves cupping hands and fingers togeth-er and clapping them alternately over the patient’s lungfields to loosen secretions for expectoration.• An ultrasonic nebulizer mobilizes thick secretionsand promotes a productive cough.

165TREATMENTS

Oxygen

therapy prevents

hypoxemia and

eases the

patient’s

breathing.

845507.qxd 8/19/08 7:16 PM Page 165


Vocabulary builders

Across

1. Space between the lungs4. Acronym for volume of air thatcan be exhaled after maximum in-spiration6. Another word for windpipe

8. Absence of breathing12. Deficiency of O2 at a cellularlevel14. Surgical excision of a lung lobe16. Slit on the lungs’ medial sur-face

17. Bony structures that form theposterior walls of the nasal pas-sages18. The lung that’s shorter, broader,and larger than the other19. Unusually slow, regular respi-rations

Down

1. Type of ventilation that uses apositive-pressure system2. Most important muscle for respi-ration3. Drug type that acts to suppresscough5. Eponym for a mask designed todeliver a high-flow, precise O2mixture7. Another word for nostrils

9. Another word for larynx

10. The respiratory system struc-ture that separates the nasal pas-sages11. Plural form of pharynx

13. Chief respiratory unit for gasexchange15. Eponym for respirations char-acterized by irregular periods ofapnea alternating with four or fivebreaths of the same depth17. Another word for tracheal bi-

furcation

At a crossroadsCompleting this crossword puzzle will help you breathe moreeasily about respiratory system terms. Good luck!


1 2 3

4 5

6 7

8

9

10

11

12 13

14 15

16

17

18

19

No need to

hyperventilate.

This is just a

game.

845507.qxd 8/19/08 7:16 PM Page 166



Match gameWhen assessing a patient’s respiratory system, it’s important to know the terms fordifferent breath sounds. Match the description of each breath sound below to its name.

Clues

Normal sounds

1. Loud, high-pitched sounds that are heard atthe manubrium and are loudest on expiration____

2. Sounds heard in the lung’s periphery, in frontof the chest, on both sides, and in back thatare longer and louder during inspiration thanexpiration ____

3. Soft, medium-pitched, breezy sounds thatare lower pitched than bronchial sounds buthigher pitched than vesicular sounds ____

Abnormal sounds

4. Sounds like hairs being rubbed together,usually heard first over the lung bases ____

5. Loud, coarse, low-pitched bubbling soundsheard primarily during expiration ____

6. High-pitched, musical sounds that may oc-cur during both inspiration and expiration butpredominantly during expiration ____

7. Coarse, low-pitched sounds heard at theanterolateral chest wall (in front, near the ribs)during inspiration and expiration that soundlike pieces of sandpaper being rubbedtogether ____

8. Crowing sound heard during inspiration,caused by air whistling as it passes throughswollen upper airways ____

9. Abnormally diminished breath sounds in ar-eas of the lung ____

10. Lack of sound over areas of the lungs thatnormally have breath sounds ____

Choices

A. Absent

B. Bronchial

C. Bronchovesicular

D. Crackles

E. Decreased

F. Pleural friction rubs

G. Rhonchi

H. Stridor

I. Vesicular

J. Wheezes

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1. ____ ____ ____ ____ ____ ____

2. ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____

3. ____ ____ ____ ____ ____

4. ____ ____ ____ ____ ____

5. ____ ____ ____ ____ ____ ____ ____

1. The Greek word for breath, spirit, or wind2. Sudden, forceful, involuntary contraction of the smooth muscle of the bronchi3. Small, hairlike projections in the trachea4. The latin word for lung5. The Greek word for throat

You probably enter a house

through a door, but my

friends—the lungs—admit my

blood vessels and the

mainstem bronchi through

what structure?

845507.qxd 8/19/08 7:16 PM Page 168




1.

2.

3.

4.

5.

845507.qxd 8/19/08 7:16 PM Page 169


1. B; 2. I; 3. C; 4. D; 5. G; 6. J; 7. F; 8. H; 9. E; 1O. A

Match game

1. Pneuma; 2. Bronchospasm; 3. Cilia; 4. Pulmo; 5. PharynxAnswer to puzzle—Hilum

Talking in circles

1. Conchae; 2. Trachea; 3. Alveoli; 4. Carina; 5. Mediastinum

O see, can you say?

At a crossroads

Answers

1M E

2D I

3A S T I N U M

E I N4F

5V C

C A6T R A C H E A E

7N

H P I8A P N E A

A H T9V T R

N R U O10S R E

I A S I11P E U S

C G S C12H Y P O X I

13A

A M I E A T C

L V B R U I14

L O B E C T O M Y M15B N

X N16H I L U M

G O S17C O N C H A E T

A S18R I G H T

I

N19B R A D Y P N E A

845507.qxd 8/19/08 7:16 PM Page 170

GI structure and function

This chapter introduces terms associated with the GI sys-tem, the system responsible for digestion and elimination.The first part of the word gastrointestinal, gastro-, is aGreek word that means stomach; it’s used in many med-ical terms. The second part of the word refers, of course,to the intestines. But the GI system includes more thanjust the stomach and the intestines. (See Pronouncingkey GI system terms, page 172.)

Two partsThe GI system has two major components:• alimentary canal (also called the GI tract)—themouth, pharynx, esophagus, stomach, intestines, rectum,and anus• accessory GI organs—the liver, gall-bladder, biliary duct system, and pancreas.

Two functionsTogether, the alimentary canal and the ac-cessory organs serve two major functions:

8

Health assessmentGastrointestinal system

Just the facts


♦ terminology related to the structure and function ofthe GI system

♦ terminology needed for physical examination of theGI system

♦ tests that help diagnose GI disorders

♦ common GI disorders and their treatments.

Let’s see. Gastro

means stomach;

entero means

intestine; and -ology

means study. Seems

simple—

gastroenterology isthe study of the

stomach and

intestines.

845508.qxd 8/19/08 5:42 PM Page 171

• digestion—the breakdown of food and fluid into sim-ple chemicals that can be absorbed into the bloodstreamand transported throughout the body• elimination—the expulsion of waste products fromthe body through excretion of feces.

Alimentary canalHere are the terms and descriptions of structures of thealimentary canal.

MouthAlso called the buccal cavity or oral cavity, the mouthis bounded by the lips, cheeks, palate (the roof of themouth), and tongue. It also contains the teeth. The mouthinitiates the mechanical breakdown of food. Ducts con-nect the mouth with three major pairs of salivaryglands, which secrete saliva to moisten food duringchewing and convert starch into maltose. The three pairsare:• parotid—located at the side of the face in front of andbelow the external ear• submandibular—located, as the name indicates, be-neath the mandible, or lower jaw

172GASTROINTESTINAL SYSTEM

The breakdown

of food begins in

the oral cavity—

that’s the mouth.

Below is a list of key terms related to the GI system, along withthe correct ways to pronounce them


Pronouncing key GI system terms

Anastomosis

Cachexia

Cholangiogram

Diverticulosis

Gastroenteritis

Submandibular

Tunica adventitia

UH-NAS-TUH-MOH-SIS

KUH-KEK-SEE-UH

KOH-LAN-JEE-OH-GRAM

DEYE-VER-TIK-YOO-LOH-SIS

GAS-TROH-EN-TER-EYE-TIS

SUHB-MAN-DIHB-YOU-LUHR

TOO-NIK-UH AD-VEN-TI-SHUH

845508.qxd 8/19/08 5:42 PM Page 172

• sublingual—located, as the name indicates, under thetongue. (See Structures of the GI system.)

173GI STRUCTURE AND FUNCTION

The GI system includes the alimentary canal (the pharynx, esophagus, stomach, and small and large intestines) and the accessoryorgans (the liver, biliary duct system, and pancreas). These structures are shown below.


Structures of the GI system

Parotid gland

Teeth

Submandibular gland

Pharynx(FAHR-RINGKS)

Esophagus

Hepatic bile duct

Liver

Cystic duct

GallbladderPancreas

Hepatic flexure

Ascending colonJejunum(JEH-JOO-NUHM)Cecum

Vermiform appendix(VER-MUH-FORM UH-PEN-DIKS)

Anal canal

Tongue

Mouth

Epiglottis

Sublingual gland

Stomach

Spleen

Common bile duct

DuodenumSplenic flexure

Transverse colon

Descending colon

Ileum(ILL-EE-UHM)Sigmoid colonRectum

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PharynxThe pharynx, or throat, a cavity extending from the baseof the skull to the esophagus, aids swallowing by grasp-ing food and propelling it toward the esophagus.

EsophagusThe esophagus is a hollow, muscular tube that extendsfrom the pharynx through the mediastinum to the stom-ach. The esophageal sphincter (a sphincter at the upperborder of the esophagus) must relax for food to enter theesophagus. Peristalsis (the rhythmic contraction and re-laxation of smooth muscle) propels liquids and solidsthrough the esophagus into the stomach.

StomachThe stomach is a collapsible, pouchlike structure in theupper left part of the abdominal cavity, just below the di-aphragm. Its upper border attaches to the lower end ofthe esophagus. The cardiac sphincter guards the open-ing to the stomach and opens as food approaches. It alsoprevents stomach contents from reentering the esopha-gus (reflux). The lateral surface of the stomach is calledthe greater curvature; the medial surface, the lessercurvature.

The stomach serves as a temporary storage space forfood and also begins digestion. It has four main regions:

The cardia lies near the junction of the stomach andesophagus.

The fundus is the enlarged portion above and to theleft of the esophageal opening into the stomach.

The body is the middle portion of the stomach.

The pylorus is the lower portion, lying near the junc-tion of the stomach and the duodenum.

IntestinesAfter mixing food with gastric secretions, the stomachbreaks it down into chyme, a semifluid substance, andthen moves the gastric contents into the intestines, whichconsist of the small intestine and the large intestine.


Stomach’s

the name.

Temporary

food storage

is my game.

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Small but really lo-o-o-o-n-n-gAlthough it’s called “small,” the narrow tube called thesmall intestine is actually about 20� (6.1 m) long and iscomposed of three major divisions:• The duodenum is the most superior division and mostactive in digestion.• The jejunum is the middle portion.• The ileum is the most inferior portion.

The small intestine completes food digestion. Foodmolecules are absorbed through its wall into the circula-tory system, from which they’re delivered to body cells.

Now LARGEThe large intestine extends from the ileocecal valve(the valve between the ileum of the small intestine andthe first segment of the large intestine) to the anus. Thelarge intestine absorbs water, secretes mucus, and elimi-nates digestive wastes. It has six segments:• The cecum, a saclike structure, makes up the first fewinches of the large intestine, beginning just below theileocecal valve.• The ascending colon rises on the right posterior ab-dominal wall, then turns sharply under the liver at the he-patic flexure.• The transverse colon, situated above the small intes-tine, passes horizontally across the abdomen and belowthe liver, stomach, and spleen. At the left splenic flexureit turns downward.• The descending colon starts near the spleen and ex-tends down the left side of the abdomen into the pelviccavity.• The sigmoid colon descends through the pelvic cavity,where it becomes the rectum. (See Sigmoid has an “S”shape.)• The rectum, the last few inches of the large intestine,terminates at the anus.

Inner liningThe wall of the GI tract consists of several layers. The in-nermost layer, the mucosa (also called the tunica mu-cosa), consists of epithelial and surface cells and looseconnective tissue. The submucosa (also called the tuni-ca submucosa) encircles the mucosa. It’s composed ofloose connective tissue, blood and lymphatic vessels, anda nerve network.


Sigmoid has an“S” shape

The term sigmoid de-rives from the Greekword sigma, the name ofthe eighteenth letter ofthe Greek alphabet. InGreek, the letter is repre-sented like this: �, a kindof truncated s, whichpretty closely resemblesthe shape of the sigmoidcolon.


Memoryjogger

No pussy-footing

around this tip. To re-member the struc-tures of the large in-testine, think “CATDESIRE”:

Cecum

Ascending colon

Transverse colon

DEscending colon

SIgmoid colon

Rectum.

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Around the submucosa lies the tunica muscularis,which is composed of skeletal muscle in the mouth, phar-ynx, and upper esophagus and longitudinal and circularsmooth muscle fibers elsewhere in the tract.

Outer coveringThe visceral peritoneum is the GI tract’s outer cover-ing. In the esophagus and rectum, it’s also called the tu-nica adventitia; elsewhere in the GI tract, it’s called thetunica serosa.

The visceral peritoneum covers most of the abdomi-nal organs and lays next to an identical layer, the pari-etal peritoneum, that lines the abdominal cavity.

Vital accessoriesAccessory organs—the liver, the biliary duct system, andpancreas—contribute hormones, enzymes, and bile,which are vital to digestion. They deliver their secretionsto the duodenum through the hepatopancreatic ampul-la, also called the ampulla of Vater (named after Abra-ham Vater, a German anatomist). (See The little jug.)

The entry of bile and pancreatic juice is controlled bya muscular valve called the hepatopancreatic sphinc-ter, or Oddi’s sphincter (named after Ruggero Oddi, anItalian doctor).

Liver and lobuleThe liver’s digestive function is to produce bile for ex-port to the duodenum. The liver’s functional unit, thelobule, consists of a plate of hepatic cells, or hepato-cytes, that encircle a central vein and radiate outward.

Caps off to sinusoidsSeparating the hepatocyte plates from each other are si-nusoids, the liver’s capillary system.

Toxic clean upKupffer’s cells, which line the sinusoids, remove bacte-ria and toxins that have entered the blood through the in-testinal capillaries. (Kupffer’s cells are named after KarlWilhelm von Kupffer, a German anatomist.)


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DuctsBile, recycled from bile salts in the blood, leaves throughbiliary ducts that merge into the right and left hepaticducts to form the common hepatic duct. This duct joinsthe cystic duct from the gallbladder to form the com-mon bile duct, which leads to the duodenum.

Bully for bileA yellow-greenish liquid composed of water, choles-terol, bile salts, electrolytes, and phospholipids, bilebreaks down fats and neutralizes gastric secretionsin chyme. Bile prevents jaundice by assisting withexcretion of conjugated bilirubin, an end productof normal hemoglobin breakdown.

GallbladderThe gallbladder is a pear-shaped organ that’s nestled un-der the liver and joined to the larger organ by the cystic


Who could resist breaking down hepatopancreatic ampulla?

Easy ones first

Hepato- comes from the Greek word for the liver, hepatikos.

Pancreatic originated from the Latin term pancreaticus, whichmeans pertaining to the pancreas.

Now for the hard part

Ampulla is a Latin term that means little jug or, in medical terms,a flasklike dilation of a tubular structure.

All together now

When these terms are put together,they describe a structure in whichthe ducts that deliver bile and pan-creatic juice from the liver (hepato) and pan-creas (pancreatic) unite at a flasklike (ampulla) junction calledthe hepatopancreatic ampulla.


The little jug

He’s the

hepato part.

I’m the

pancreaticpart!

I’m very

proud of

my three

ducts.

845508.qxd 8/19/08 5:42 PM Page 177

duct. The gallbladder’s job is to store and concentratebile produced by the liver. (See Why not bilebladder?)

Of all the gall!When stimulated by a hormone called cholecystokinin,the gallbladder contracts, the hepatopancreatic ampullarelaxes, and bile is released into the common bile ductfor delivery to the duodenum. (See Bile, bladder, andprotein.)

PancreasThe pancreas lies behind the stomach, with its head andneck extending into the curve of the duodenum and itstail lying against the spleen. The pancreas contains twocell types:• endocrine cells, from which hormones are secretedinto the blood• exocrine cells, from which enzymes are secretedthrough ducts to the digestive system.

In the islets of LangerhansThe pancreas’s endocrine function involves the islets ofLangerhans, named for Paul Langerhans (1847-1888),the German doctor who discovered them. These micro-scopic structures—over 1 million of them—are scatteredthroughout the pancreas and house two cell types:• alpha cells, which secrete glucagon, a hormone thatstimulates the breakdown of glycogen to glucose in theliver—a process referred to as glycogenolysis• beta cells, which secrete insulin to promote carbo-hydrate metabolism.


Before you can perform a complete examination of theGI tract, you need to understand the associated terminol-ogy:• Aaron’s sign, named for American physician CharlesAaron (1866-1951), refers to pain in the chest or abdomi-nal area that’s elicited by applying gentle but steadily in-creasing pressure over McBurney’s point (2� [5.1 cm] be-low the right anterior superior spine of the ilium, on a


Why notbilebladder?

We might just as wellcall the gallbladder abilebladder because thetwo words, gall and bile,

refer to the same thing.Gall appears in Old Eng-lish as early as the year825 in a translation of thePsalms. The word gall

actually refers to the yel-lowish color of bile. Theword bile, on the otherhand, is a relatively re-cent borrowing fromLatin by way of French;this word doesn’t showup in English until the17th century.


845508.qxd 8/19/08 5:42 PM Page 178

line between that spine and the umbilicus). A positivesign indicates appendicitis.• Abdominal distention refers to increased abdominalgirth—the result of increased intra-abdominal pressureforcing the abdominal wall outward.• Anorexia is a loss of appetite.• Ascites refers to the abnormal accumulation of serousfluid in the peritoneal cavity.• Auscultation is an assessment method; it means to lis-ten carefully, usually with a stethoscope.• Ballottement, lightly tapping or bouncing fingertipsagainst the abdominal wall, elicits abdominal muscle re-sistance or guarding.• Bowel sounds are auscultated with a stethoscope andprovide information about bowel motility (movement)and the underlying vessels and organs. Normally, air andfluid moving through the bowel create soft, bubblingsounds, which are often mixed with soft clicks and gur-gles, that occur every 5 to 15 seconds. Bowel sounds aredescribed using the following terms:– absent bowel sounds, when no bowel sounds areheard– borborygmi, the familiar “growling stomach” of a hun-gry patient– hyperactive, which describes rapid, high-pitched, loudgurgling sounds– hypoactive, which occur at a rate no greater than oneper minute.• Cachexia is a profound state of overall ill health andmalnutrition characterized by weakness and emaciation.• Colic is acute abdominal pain.• Constipation refers to a decreased passage of stools.A constipated stool is characteristically hard and dry.• Cullen’s sign refers to irregular, bluish hemorrhagicpatches on the skin around the umbilicus and occasional-ly around abdominal scars. Cullen’s sign indicates mas-sive hemorrhage.• Diarrhea is rapid movement of fecal material throughthe intestines that causes poor absorption of water andnutrients. Diarrhea stools are watery and frequent.• Dyspepsia is gastric discomfort, such as fullness,heartburn, bloating, and nausea, that occurs after eating.• Dysphagia is difficult or painful swallowing.• Emesis, from Greek, is an expulsion of the stomachcontents by vomiting.


Bile, bladder,and protein

Cholecystokinin is easyto dissect:Chole- is Greek for bile.Cysto- comes from theGreek word kystis,

meaning bladder.Kinin is a general termfor plasma proteins—like this hormone.


Borborygmi is

the familiar

“growling

stomach” of a

hungry patient.

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• Epigastrium refers to the upper and middle regions ofthe abdomen.• Fecal impaction is an accumulation of hardened fecesin the rectum or sigmoid colon that can’t be evacuated.• Fecal incontinence refers to an inability to preventthe discharge of feces.• Flatulence refers to a sensation of gaseous abdominalfullness.• Grey Turner’s sign is characterized by a bruiselikediscoloration of the skin of the flanks that appears 6 to 24hours after the onset of retroperitoneal hemorrhage inacute pancreatitis.• Guarding is moving away or flinching when a tenderarea of the abdomen is touched.• Heartburn, also referred to as pyrosis, is a burningsensation in the esophagus or below the sternum in theregion of the heart.• Hematemesis is vomiting blood.• Hematochezia is fresh, bright red blood passed fromthe rectum.• Hemoperitoneum refers to a leakage of blood into theperitoneal cavity.• Hepatomegaly is an enlarged liver.• Hypogastrium is the lowest, middle abdominal region.• Ileus is a mechanical intestinal obstruction.• Jaundice is a yellow appearance of the skin, mucousmembranes, and sclerae of the eyes, resulting from ele-vated serum bilirubin levels.• Meconium is the substance that fills the entire intes-tine before birth. A neonate’s first stool is called a meco-nium stool.• Melena is black, tarry stools—a common sign of upperGI bleeding.• Murphy’s sign refers to pain on deep inspiration thatoccurs when an inflamed gallbladder is palpated bypressing the fingers under the rib cage. Hepatitis mayalso produce a positive Murphy’s sign.• Nausea is an unpleasant feeling that typically precedesvomiting.• Occult blood is an amount of blood so small that itcan be seen or detected only by a chemical test or micro-scopic examination.• Odynophagia is painful swallowing.• Pica refers to the craving and ingestion of normallyinedible substances, such as plaster, charcoal, clay, wool,ashes, paint, and dirt.


Occult bloodrefers to minute

amounts of blood

that can be seen or

detected only by a

chemical test or

microscopic

examination.

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• Polyphagia is consuming abnormally large amounts offood.• Polydipsia is chronic, excessive thirst.• Rebound tenderness, also referred to as Blumberg’ssign, is pain that occurs when a hand pressing on the ab-domen is suddenly released.• Rectal tenesmus is a spasmodic contraction of theanal sphincter with a persistent urge to defecate and in-voluntary, ineffective straining. This occurs in inflamma-tory bowel disorders, such as ulcerative colitis andCrohn’s disease, and in rectal tumors.• Regurgitation is the backflowing or return of foodand fluids into the mouth without nausea or belching.• Rigidity describes a stiff abdominal wall, sometimescalled a boardlike abdomen.• Rovsing’s sign, named after the Copenhagen surgeonNiels Rovsing (1862-1927), who first described this symp-tom, occurs in acute appendicitis. Pressure on the leftlower quadrant of the abdomen will cause pain in theright lower quadrant.• Steatorrhea is excessive fat in the feces that floatsand is frothy and foul-smelling.• Tympany is a clear, hollow, drumlike sound heardwhen palpating the abdomen.• Vomiting is forcibly expelling the contents of the stom-ach through the mouth. Vomiting can be described as:– cyclic (recurring attacks of vomiting)– dry (attempt to vomit without emesis)– projectile (ejected with great force).

Diagnostic tests

This section covers diagnostic tests used to identify GIdisorders.

Blood testsSerum studies of enzymes, proteins, and formed elementsare used to investigate disorders involving the liver, pan-creas, gallbladder, and intestinal tract. You’ll see the fol-lowing tests ordered most often:• The alkaline phosphatase test measures the enzymeactivity of several alkaline phosphatase isoenzymes

181DIAGNOSTIC TESTS

845508.qxd 8/19/08 5:42 PM Page 181

found in the liver, bone, kidneys, intestines, and biliarysystem.• The Helicobacter pylori antibodies test checks forthe presence of H. pylori, which are associated withchronic gastritis and idiopathic chronic duodenal ulcera-tion.• The serum amylase test measures the level of thepancreatic enzyme alpha-amylase, which is active in thedigestion of starch and glycogen. Amylase is releasedwith pancreatic damage.• The serum bilirubin test measures serum levels ofbilirubin, the main pigment in bile and the major prod-uct of hemoglobin breakdown.• The serum lipase test measures the amount of li-pase in the blood; large amounts indicate pancreaticdamage.• The total cholesterol test measures the circulatinglevels of free cholesterol and cholesterol esters.

Radiologic and imaging testsTests that use X-rays, electromagnetic waves, and soundwaves to create images of internal structures of the GIsystem and its function include:• Abdominal X-ray, also called a flat plate (or flat anderect plates) of the abdomen, helps visualize the posi-tion, size, and structure of abdominal contents.• Barium enema is the radiographic examination of thelarge intestine after rectal instillation of barium, a radi-opaque contrast medium.• Barium swallow is the radiographic examination ofthe throat and esophagus after ingestion of a radiopaquecontrast medium.• Cholangiogram is an X-ray of the gallbladder and bil-iary duct system that’s obtained by injecting a radiopaquecontrast medium.• Computerized tomography (CT) scan translates theaction of multiple X-ray beams into three-dimensional im-ages.• Contrast radiography is a general term that describesseveral procedures that use a radiopaque contrast medi-um to accentuate differences among densities of fat, air,soft tissue, and bone.• Endoscopic retrograde cholangiopancreatography(ERCP) is a radiographic examination of the pancreatic


The different

serum tests

examine the levels

of substances in

the blood. For

example, a serum

bilirubin test

measures bilirubin

level.

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ducts and hepatobiliary tree after injection of a contrastmedium into the duodenal papilla (small nipplelike ele-vation). This test is done by use of an endoscope guidedby the use of fluoroscopy. (See I’d rather say ERCP.)• Esophagogastroduodenoscopy (EGD) allows visualexamination of the esophagus, stomach, and duodenumusing a fiberoptic endoscope.• Liver-spleen scan uses a gamma-ray camera to recordthe distribution of radioactivity within the liver andspleen after injection of a radioactive colloid.• Magnetic resonance cholangiopancreatography isused in much the same way as ERCP but isn’t as invasive.It creates images using electromagnetic waves and helpsto visualize the biliary structures, bile ducts, pancreaticducts, and gallbladder.• Magnetic resonance imaging (MRI) creates imagesby computer analysis of electromagnetic waves directedinto the tissues.• In percutaneous transhepatic cholangiography aradiopaque contrast medium is introduced through acatheter inserted through the skin into the liver to allowexamination of the biliary system.• Ultrasonography creates images of deep structuresof the body by computer analysis of ultrasonic (high-frequency sound) waves directed into and reflected fromtissues.• Upper GI and small bowel series involves the fluoro-scopic examination of the esophagus, stomach, and smallintestine after the patient ingests a contrast medium.

Other testsOther tests used to diagnose abnormalities of the GI sys-tem include:• Basal gastric secretion test measures basal acid se-cretion during fasting by aspirating stomach contentsthrough a nasogastric (NG) tube.• Breath hydrogen analysis is a simple method of de-tecting lactose intolerance.• Colonoscopy is an endoscopic examination of thecolon.• Endoscopy is a visual inspection of a body cavity us-ing an optical instrument called an endoscope.• Esophageal acidity test evaluates the competence ofthe lower esophageal sphincter—the major barrier to re-

183DIAGNOSTIC TESTS

I’d rather sayERCP

Endoscopic retrograde

cholangiopancreatogra-

phy (ERCP) is a realmouthful, but this word iseasy to dissect: Endo-

scopic refers to the opti-cal instrument used inthe procedure. Retro-

grade means movingagainst the usual flowand refers to dye inject-ed the wrong way in theampulla of Vater. Cholan-

gio- refers to the biliarytract, pancrea- meanspancreas, and -graphy isa recording. Therefore,ERCP is a recording ofthe function of the biliarytract and pancreas.


845508.qxd 8/19/08 5:42 PM Page 183

flux—by measuring the pH within the esophagus with anelectrode that is attached to a special catheter.• Fecal lipids test is used to detect excessive excretionof lipids in patients with signs of malabsorption.• Gastric acid stimulation test measures the secretionof gastric acid for 1 hour after subcutaneous injection ofa drug that stimulates gastric acid output.• Gastric emptying study is used to diagnose impairedgastric motility.• Laparoscopy is an endoscopic examination of the inte-rior of the peritoneal cavity.• Manometry is the use of water-filled catheters con-nected to pressure transducers in different parts of the GIsystem to evaluate contractility.• Percutaneous liver biopsy involves aspiration of acore of liver tissue for analysis.• Peritoneal fluid analysis examines a specimen ofperitoneal fluid obtained by paracentesis for appearance,red blood cell and white blood cell counts, cytologicstudies, microbiologic studies for bacteria and fungi, anddeterminations of protein, glucose, amylase, ammonia,and alkaline phosphatase levels.• Sigmoidoscopy is an endoscopic examination of thesigmoid colon.• Stool culture is a bacteriologic examination of feces.• Urine bilirubin test detects abnormally high urineconcentrations of direct bilirubin, possibly indicating liv-er disease.• Urine urobilinogen test detects impaired liver func-tion by measuring urine levels of urobilinogen, which re-sults from the reduction of bilirubin by intestinal bacteria.

Disorders

Here are descriptions of disorders of the organs of the GIsystem.

Mouth and esophagusThe following are important terms used to describe dis-orders of the upper alimentary canal:• Achalasia is an esophageal motility disorder resultingfrom neural dysfunction and lower esophageal sphincterdysfunction.


Sigmoidoscopyis an endoscopic

examination of

the sigmoid

colon.

Here’s a

little tune I like

to call

“Getting to

know me.”

845508.qxd 8/19/08 5:42 PM Page 184

• Cleft lip and cleft palate are developmental anom-alies present at birth. These congenital disabilities typi-cally require surgical repair.• Esophageal atresia refers to a closed esophagus.• Esophageal diverticula are hollowed outpouchings inthe esophageal wall.• Esophageal stricture is a narrowing of the esopha-gus.• Esophageal varices are enlarged, torturous veins in thelower esophagus that are caused by portal hypertension.• Erythroplakia is a red, velvelty mucosal lesion on thesurface of the oral mucosa.• Esophagitis is the inflammation of the mucousmembrane that lines the esophagus.• Gastroesophageal reflux refers to the backflow ofgastric or duodenal contents into the esophagus. Se-vere reflux disease is called gastroesophageal refluxdisease (GERD).• Gingivitis is an inflammation of the gums.• Glossitis is an inflammation of the tongue.• Hiatal hernia is the protrusion of the stomachthrough a structural defect in the diaphragm at theesophageal opening.• Kaposi’s sarcoma is a cancer associated with acquiredimmunodeficiency syndrome. Lesions occur in the skin,lymph nodes, and viscera.• Leukoplakia are firmly attached white patches on theoral mucosa.• Mallory-Weiss syndrome refers to lacerations in themucous membrane at the esophagogastric junction thatresult in massive bleeding. The syndrome is typically pre-ceded by vomiting.• Periodontitis refers to progression of gingivitis involv-ing an inflammation of the oral mucosa.• Pyloric stenosis is an obstruction of the pyloricsphincter caused by hypertrophy of the sphincter muscle.It’s most commonly seen in boys between ages 1 and 6months. • Stomatitis is an inflammation of the mouth.• Tracheoesophageal fistula is an abnormal connec-tion between the trachea and the esophagus.• Vincent’s stomatitis, also known as trench mouth, isa severe form of gingivitis that causes necrosis and ulcer-ation of the gums.

185DISORDERS

Esophageal

atresia means

the esophagus

is closed.

845508.qxd 8/19/08 5:42 PM Page 185

Stomach and intestinesHere are terms that relate to diseases and abnormalitiesof the stomach and intestines:• Ascites is the accumulation of fluid in the peritonealcavity.• Celiac disease is a chronic disease in which an indi-vidual can’t tolerate foods containing gluten (usuallyfound in wheat, rye, barley, and oats).• Crohn’s disease is a chronic inflammatory bowel dis-ease that usually involves the proximal portion of thecolon and, less commonly, the terminal ileum. It’s namedafter the American surgeon Burrill Crohn (1884-1983),who first described it in 1932.• Curling ulcer is a stress ulcer of the duodenum thatresults from burn injuries.• Cushing ulcer is a stress ulcer of the duodenum asso-ciated with severe head trauma or brain surgery.• Diverticular disease refers to bulging pouches (di-verticula) in the GI wall—typically in the sigmoidcolon—that push the mucosal lining through the sur-rounding muscle. (See A diversion on diverticulum.) Di-verticular disease has two clinical forms:– Diverticulitis is the inflammation of one or more di-verticula.– Diverticulosis is the presence of diverticula withoutaccompanying inflammation.• Gastritis refers to inflammation of the stomach andstomach lining.• Gastroenteritis is inflammation of the lining of thestomach and intestines that accompanies numerous GIdisorders.• Hirschsprung’s disease, also called congenitalmegacolon, is a congenital disorder of the large intestinecharacterized by the absence or marked reduction ofnerve cells in the colorectal wall, which results in im-paired intestinal motility and constipation.• Inactive colon is a state of chronic constipation that,if left untreated, may lead to fecal impaction.• Inguinal hernia is protrusion of the large or small in-testine, omentum, or bladder into the inguinal canal re-sulting from weakened abdominal muscles, traumatic in-jury, or aging. The hernia is:– reducible if it can be moved back into place easily– incarcerated if it can’t be reduced


Curling ulcer gets its

name from an English

surgeon, Thomas

Curling, who lived

from 1811 to 1888 and

was the first person

to describe this

condition.

845508.qxd 8/19/08 5:42 PM Page 186

– strangulated if a portion of the herniated intestine be-comes twisted or swollen so that blood flow is impaired.• Intestinal obstruction occurs when the lumen(opening) of the bowel is partly or fully blocked. Obstruc-tion is classified as mechanical or nonmechanical:– Mechanical obstruction results from foreign bodiesor compression of the bowel wall.– Nonmechanical obstruction results from physiologicdisturbances, such as paralytic ileus, electrolyte imbal-ance, and blood clots that cause ischemia of the mesen-teric vessels.• Intussusception refers to a telescoping of a portion ofbowel into an adjacent distal portion.• Irritable bowel syndrome is a condition character-ized by diarrhea, resulting from increased bowel motility,alternating with constipation.• Lactose intolerance is the inability to digest milk sug-ar.• Necrotizing enterocolitis is an inflammatory diseasecharacterized by diffuse or patchy intestinal necrosis andis accompanied by infection in about one-third of cases.It mostly affects premature infants.• Paralytic ileus is a physiologic form of intestinal ob-struction that usually develops in the small bowel afterabdominal surgery.• Peptic ulcer is a disruption in the gastric or duodenallining that occurs when normal defense mechanisms areoverwhelmed or impaired by acid or pepsin. An acuteform of peptic ulcer is called a stress ulcer.• Peritonitis is an acute or chronic inflammation of theperitoneum (the membrane that lines the abdominalcavity and covers visceral organs).• Pseudomembranous enterocolitis is an acute in-flammation and necrosis (tissue death) of the small andlarge intestines, usually affecting only the mucosa.• Ulcerative colitis is a chronic, inflammatory diseasethat affects the mucosa of the colon and produces edemaand ulcerations. It typically begins in the rectum and sig-moid colon and may extend upward into the entire colon.It rarely affects the small intestine.• Volvulus is a twisting of intestine at least 180 degreeson its mesentery, resulting in blood vessel compressionand ischemia.

187DISORDERS

A diversion ondiverticulum

A diverticulum is, in fact,a diversion. The smallpouches divert contentsof the GI tract; this actiongives the structures theirname.


Got milk?

Not if you’re

lactose

intolerant, you

don’t.

845508.qxd 8/19/08 5:42 PM Page 187

Anus and rectumDisorders of the anus and rectum include:• Anal fissure is a laceration or crack in the lining of theanus.• Anorectal abscess is a localized collection of pus dueto inflammation of the soft tissue near the rectum oranus.• Anorectal fistula is an abnormal opening in the analskin that may communicate with the rectum. Inflamma-tion caused by an anorectal abscess may cause the fistulato form.• Anorectal stenosis is narrowing of the anorectalsphincter.• Anorectal stricture occurs when the anorectal lumensize decreases.• Hemorrhoids are varicosities in the veins of the rec-tum or anus that result in swelling and pain.• Pilonidal cyst is a hair-containing dermoid cyst thatforms in the midline gluteal fold.• Proctitis is an acute or chronic inflammation of therectal mucosa.• Pruritus ani is perianal itching, irritation, or superfi-cial burning.• Rectal polyps are masses of tissue that rise above themucosal membrane and protrude into the GI tract.• Rectal prolapse is the circumferential protrusion ofone or more layers of the mucous membrane through theanus.

Accessory organsDisorders of the appendix, liver, gallbladder, and pan-creas include:• Appendicitis is an inflammation of the vermiform ap-pendix due to an obstruction.• Cholecystitis is acute or chronic inflammation of thegallbladder, typically caused by gallstones.• Cholelithiasis is the presence of gallstones in the gall-bladder. (See Lithos = stone.)• Choledocholithiasis occurs when gallstones passfrom the gallbladder and lodge in the common bile duct,causing complete or partial obstruction.


Proctitis is an

acute or chronic

inflammation of

the rectal

mucosa.

845508.qxd 8/19/08 5:42 PM Page 188

• Cirrhosis refers to a chronic, degenerative liver dis-ease in which the lobes are covered with fibrous tissue,the liver parenchyma degenerates, and the lobules are in-filtrated with fat.• Fatty liver, also known as steatosis, is the accumula-tion of triglycerides and other fats in liver cells.• Hepatic coma is a neurologic syndrome that developsas a complication of hepatic encephalopathy.• Hepatic encephalopathy is a degenerative brain con-dition caused by advanced liver disease.• Hepatitis occurs in two forms, nonviral and viral:– Nonviral hepatitis is usually caused by exposure totoxins or drugs.– Viral hepatitis is an acute inflammation of the livermarked by liver-cell destruction, necrosis, and autolysis(destruction of tissue by enzymes).

Assessment findings are similar for the differenttypes of hepatitis. The six forms of viral hepatitis are:– type A, which is spread by direct contact through theoral-fecal route– type B, which is transmitted by contaminated serumthrough blood transfusion, needles, I.V. drug use, and di-rect contact with body fluids– type C, which is spread through needle sticks, bloodtransfusion, and I.V. drug use– type D, which is found only in patients with acute orchronic episodes of hepatitis B and requires the presenceof hepatitis B surface antigen (hepatitis D is rare, exceptamong I.V. drug users)– type E, which is transmitted by the oral-fecal andwater-borne routes, much like type A (because this virusis inconsistently shed in the feces, detection is difficult)– type G, which is transmitted by parenteral and sexualmeans, has been discovered most recently.• Hepatocellular carcinoma (hepatocarcinoma) iscancer of the liver.• Pancreatitis is an acute or chronic inflammationof the pancreas.• Portal hypertension is increased pressure in theportal vein as a result of obstruction of blood flowthrough the liver.• Wilson’s disease is a rare inherited metabolic dis-order characterized by excessive copper retention inthe liver, brain, kidneys, and corneas. These depositsof copper eventually lead to hepatic failure.

189DISORDERS

Lithos = stone

Cholecystitis is a combi-nation of Greek terms:chole means bile; cyst

means bladder, and -itismeans inflammation. Soit makes sense thatcholecystitis is inflam-mation of the gall-bladder.

Now take it one stepfurther. Lithos is theGreek term for stone, soit makes sense thatcholelithiasis is the termfor gallstones.


Many words

associated with

me begin with

hepa-, from the

Greek word for

liver.

845508.qxd 8/19/08 5:42 PM Page 189

Treatments

Here are terms identifying surgical procedures and othertreatments to correct GI disorders.

GI tubesHere are terms related to GI tubes used to treat patientswith GI disorders:• Gastric lavage is irrigation or washing of the stomachwith sterile water or saline solution using an NG tube.• Gavage is feeding a patient through a stomach tube.• Intestinal decompression removes fluids and gasfrom the intestine by the insertion of one of several typesof tubes:– The Miller-Abbott tube is a double-lumen tube inwhich one lumen contains a weighted balloon to easepassage and the other lumen facilitates drainage.– The Harris tube, used for gastric and intestinal de-compression, is a mercury-weighted single-lumen tubethat’s inserted through the nose and carried through thedigestive tract by gravity.– The Cantor tube, used to relieve obstruction in thesmall intestine, is a double-lumen nasoenteric tube. Onelumen is used to inflate the distal balloon with air; theother, to instill mercury to weight the tube. The tube alsoallows for aspiration of intestinal contents.• Nasogastric intubation is insertion of a tube into thestomach through the nose.• Sengstaken-Blakemore intubation is insertion of atriple-lumen catheter used to stop hemorrhaging fromesophageal varices. Two lumens end in balloons; one isinflated in the stomach to hold the catheter in place andcompress the vessels around the cardia, and the other isinflated in the esophagus to exert pressure againstvarices in the wall of the esophagus. The third lumen isused to aspirate (withdraw) stomach contents.

Pharyngeal and esophageal surgeriesSurgical procedures performed on the esophagus include:• cricopharyngeal myotomy—a partial or total incisionof the cricopharyngeal muscle that relieves diverticula orsevere cricopharyngeal muscle spasm


Lavage and gavageare two similar

sounding words that

can be easily

confused. Just

remember, lavagemeans the stomach

is being laundered;

gavage means you’re

giving food to the

stomach.

845508.qxd 8/19/08 5:42 PM Page 190

• esophagectomy—removal of part of the esophagus.• esophagogastrectomy—removal of all or part of thestomach and esophagus• esophagogastrostomy—removal of a portion of theesophagus then connecting the remaining healthy portionto the stomach• esophagojejunostomy—attachment of the jejunum tothe esophagus to provide a bypass for food for patientswith esophageal stricture.

Gastric and abdominal surgeriesSurgical procedures on the stomach are explained below:• Antrectomy is the removal of the antrum, the lowerpart of the stomach, which produces gastric acid.• Billroth I is a partial removal of the distal portion ofthe stomach; the remaining stomach is connected to theduodenum.• Billroth II is a surgical excision of a portion of thestomach with connection of the remaining portion to thejejunum.• Gastric bypass surgery (Roux-en-y) is a weight-loss(bariatric) procedure in which a small pouch is created atthe top of the stomach and a bypass is created to a por-tion of the small intestine.• Gastrostomy is the creation of a hole into the stomachthrough the abdominal wall to insert an feeding tube.• Laparotomy is a surgical opening of the abdomen.(See Gastric lingo.)• Pyloroplasty is surgical enlargement of the pylorus toimprove drainage of gastric contents into the small bow-el.• Total gastrectomy is removal of the entire stomach.

Bowel surgeryListed below are important surgical terms concerning thesmall intestine, large intestine, and colon:• Abdominal perineal resection is a procedure inwhich a colostomy is created and the distal sigmoidcolon, rectum, and anus are removed.• Anastomosis is a surgical procedure in which twoblood vessels, ducts, or other tubelike structures arejoined to allow the flow of substances between them.

191TREATMENTS

Remember, the

suffix -ectomy means

removal of, and the

suffix -ostomy means

creation of an

opening.

The Austrian

surgeon Christian

Albert Theodore

Billroth gave his name

to two surgeries.

Both involve removing

a portion of the

stomach. I’ll keep all

my portions, thank

you.

845508.qxd 8/19/08 5:42 PM Page 191

• Colectomy is excision of a portion of the colon.• Hemicolectomy is the removal of one-half or less ofthe colon.• Hemorrhoidectomy is the surgical excision of a hem-orrhoid.• Ileostomy is the creation of an opening between theileum and the abdominal wall through which fecal matteris expelled.• An ostomy is an artificial opening or stoma created inthe GI or urinary canal or in the trachea.

ColostomyA colostomy, bowel surgery that creates an opening be-tween the colon and the abdominal wall through whichfeces are expelled, may be created in different portionsof the intestine and structured several ways.

Different locationsNamed according to their location in the colon,colostomies can be:• ascending—located on the ascending portion of thecolon• transverse—located on the transverse portion of thecolon• descending—located on the descending portion of thecolon• sigmoid—located on the sigmoid colon.

Different structuresThese are the main types of colostomy construction:• A double-barrel colostomy creates two separatestomas—usually temporarily—on the abdominal wall.The proximal stoma is the functioning end and is contin-uous with the upper GI tract. The distal stoma, also re-ferred to as a mucous fistula, opens into the nonfunc-tioning section of the colon that’s continuous with therectum.• An end colostomy creates a single stoma on the ab-domen created from the end of the colon, which isbrought out through an opening in the abdominal wall.• A loop colostomy involves bringing a loop of bowelthrough an incision in the abdominal wall.


Gastric lingo

Let’s run another lap

In practice, people com-monly refer to an ex-

ploratory laparotomy asan exploratory lap or ex-lap. So you might hearsomeone say, “We needto take this patient for anexploratory lap.”

NG tube

Rarely will you hearsomeone refer to a naso-

gastric tube by its fullname. In practice, it'ssimply referred to as anNG tube.

The realworld

845508.qxd 8/19/08 5:42 PM Page 192

Liver surgeryImportant terms concerning liver surgery are listedbelow:• Hepatic lobectomy is removal of a lobe of the liv-er.• Liver resection is removal of a portion of the dis-eased or damaged liver tissue.• Liver transplant is reserved for patients with alife-threatening liver disorder that doesn’t respond toother treatment.• Partial hepatectomy is excision of a portion ofthe liver.• Transjugular intrahepatic portosystemic shunt is aprocedure in which the radiologist cannulates (creates atunnel) in the right internal jugular vein and then insertsa metallic, flexible stent into a new pathway created byballoon dilation of the tissue between the hepatic andportal veins in the liver. This artificial shunt creates anew pathway for blood flow and reduces portal hyperten-sion.

Gallbladder and appendix surgerySurgical procedures performed on the gallbladder and ap-pendix are explained below:• Appendectomy is the removal of the vermiform ap-pendix.• Cholecystectomy is removal of the gallbladder. (SeeOpen chole.)• Cholecystoduodenostomy is anastomosis of the gall-bladder and duodenum.• Choledochojejunostomy is anastomosis of the com-mon bile duct to the jejunum of the small intestine.

193TREATMENTS

Let me help with

transjugularintrahepatic

portosystemic shunt.Transjugular means the

catheter is inserted

through the jugular;

intrahepatic means it

goes through the hepatic

vein; porto means it then

goes through the portal

vein; systemic means it

then shunts blood into

systemic circulation.

Open chole

You may hear a conven-tional cholecystectomy

be referred to as anopen chole, pronouncedKOH-LEE. This means anopen abdominal incisionwas required to removethe gallbladder, as op-posed to laparoscopic

surgery, which doesn’trequire an abdominal in-cision.

The realworld

845508.qxd 8/19/08 5:42 PM Page 193


Vocabulary builders

Across

2. Rhythmic contraction and relax-ation of smooth muscle in the ali-mentary canal7. Liver’s functional unit9. Inflammation of the tongue11. Another name for Vincent’s

stomatitis (two words)12. Difficult or painful swallowing13. Clear, hollow, drumlike soundheard on abdominal palpation

15. Greek word that means littlejug16. Saclike structure that makes upthe first few inches of the large in-testine17. Yellow-green liquid that breaksdown fats and neutralizes gastricsecretions

Down

1. Pear-shaped organ nestled un-der the liver2. Roof of the mouth3. Eponym for diagnostic sign ofappendicitis4. Enlarged portion of the stomachabove and to the left of theesophageal opening5. Canal also called the GI tract

6. Root from Greek that meansstomach8. Growling sound in the stomachthat indicates hunger10. Part of the colon named after aGreek letter14. Also called the buccal cavity

16. Acute abdominal pain


1

2 3 4

5 6

7

8

9 10

11

12

13 14

15

16

17

At a crossroadsCompleting this crossword puzzle will help you digest GIsystem terms. Good luck!

Eating

helps me

think.

845508.qxd 8/19/08 5:42 PM Page 194



1.

2.

3.


Match gameEponyms can be confusing. There are lots of eponyms for GI structures, disorders, andtests. See if you can match each person to their discovery.

Clues

1. ________ sphincter

2. Ampulla of _______

3. _______ cells

4. Islets of _______

5. _______’s disease

6. ________’s sign

Choices

A. Karl Wilhelm von Kupffer, German anatomist

B. Paul Langerhans, German doctor

C. Ruggero Oddi, Italian doctor

D. Charles Aaron, American physician

E. Abraham Vater, German anatomist

F. Burnil Crohn, American surgeon

845508.qxd 8/19/08 5:42 PM Page 195


1. C; 2. E; 3. A; 4. B; 5. F; 6, D

Match game

1. Tunica adventitia; 2. Submandibular; 3. Cholangiogram

O see, can you say?

At a crossroads

Answers

1G

2P E

3R I S T A L S I S

4F

A O L U

L V5A L N

6G

A S7

L O B U L E D A

T I I L8B U S

E N M A9G L O S S I T I

10S

G E D R R I

N D B O G11T R E N C H M O U T H M

A R R O

R12D Y S P H A G I A

13T Y

14M P A N Y G D

O15A M P U L L A

16C E C U M I

O T17B I L E H

I

C

Enough

about me.

Time to move

on to the

urinary

system.

845508.qxd 8/19/08 5:42 PM Page 196

Urinary structure and function

The urinary tract is the body’s water treatment plant. Itfilters the blood and collects and expels the resulting liq-uid waste products as urine. To help you understandmany of the terms relating to this waste control system,three key root words deserve special attention.

In the key of peeThe first key root is the syllable ur- or its other forms,urin- or uro-. This term derives from the Greek verbourein, which means to urinate. Appropriately, thestudy of the urinary system is called urology.

Two keys to the kidneysThe second and third key terms refer to the kidneys. Thesecond is the adjective renal. This word derives fromren, the Latin word for kidney. The kidneys are the filterof our bodies’ water treatment plant and perform a num-ber of other vital functions, including:• regulating acid-base balance

9

Health assessmentUrinary system

Just the facts


♦ terminology related to the structure and function ofthe urinary system

♦ terminology needed for physical examination of theurinary system

♦ tests that help diagnose urinary system disorders

♦ common urinary system disorders and their treat-ments.

845509.qxd 8/19/08 5:40 PM Page 197

• regulating electrolyte balance• regulating blood pressure• aiding in red blood cell (RBC) formation.The word renal can show up in various medical con-texts.

A medical subspecialization within urology focuseson just the renal system. The name of this specialization,nephrology, employs the Greek word for kidney,nephros, instead of the Latin ren. Nephro-, or nephr-,our third key term, is identical in meaning with ren, andyou’ll find many words containing these two roots side byside. (See Pronouncing key urinary system terms.)

KidneysThe kidneys are bean-shaped, highly vascular organs lo-cated at the small of the back on either side of the verte-bral column between the 12th thoracic and 3rd lumbarvertebrae. The right kidney, crowded by the liver, is posi-tioned slightly lower than the left. Although each kidneyis only about 4� (10 cm) long, these organs are complicat-ed structures with many functioning units. They receiveabout 20% of the blood pumped by the heart each minute.

198URINARY SYSTEM

Memoryjogger

By thinking“BARE,”

you’ll remember thatthe kidneys affectfour main functionsof the body:

Blood pressure

Acid-base balance

Red blood cell forma-tion

Electrolyte balance.

Below is a list of key terms related to the urinary system, alongwith the correct ways to pronounce them.


Pronouncing key urinary systemterms

Azotemia

Creatinine

Cystourethroscopy

Glomerulonephritis

Nephrotic syndrome

Prostatitis

Pyuria

AZ-OH-TEE-MEE-UH

KREE-AT-IH-NIN

SIS-TOH-YOU-REE-THROHS-KUH-PEE

GLAW-MER-YUH-LOH-NEF-REYE-TIS

NEH-FROT-IK SIN-DROHM

PROS-TUH-TEYE-TIS

PYE-YOU-REE-UH

845509.qxd 8/19/08 5:40 PM Page 198

Adrenal gland influenceAtop each kidney lies an adrenal gland. These glands af-fect the renal system by influencing blood pressure andsodium and water retention by the kidneys.

Checking in and checking outThe kidneys receive waste-filled blood from the renalartery, a large branch of the abdominal aorta. Afterpassing through a complicated network of smaller bloodvessels and filtering structures within the kidneys, the fil-tered blood returns to the circulation by way of the renalvein, which empties into the inferior vena cava, themajor ascending vein of the lower body. (See Majorstructures of the kidney, page 200.)

A tri-umph of organ-izationEach kidney has three regions. The renalcortex, or outer region, contains blood-filtering mechanisms. The renal medulla,or middle region, contains 8 to 12 renalpyramids, which are striated wedges com-posed of tubular structures.

The tapered portion of each pyramid,called the apex, empties into a cuplike calyx(plural: calyces). The calyces channel urine from the re-nal pyramids into the renal pelvis, which is an expan-sion of the upper end of the ureters.

Getting to know the nephronThe nephron is the functional and structural unit of thekidney; each kidney contains about 1.25 millionnephrons. The nephron has two main activities:• selective resorption and secretion of ions• mechanical filtration of fluids, wastes, electrolytes, andacids and bases.

Glom on the glomerulusThree processes—glomerular filtration, tubular reab-sorption, and tubular secretion—take place in thenephrons, ultimately leading to urine formation.Each nephron consists of a long tubular system with aclosed, bulbous end called the glomerular capsule, orBowman’s capsule. Within the capsule are a cluster ofcapillaries called the glomerulus (plural: glomeruli).The glomerulus acts as a filter and passes protein-free

199URINARY STRUCTURE AND FUNCTION

My threeregions• The renal cortex(outer region) con-tains about 1.25million renaltubules.

• The renal medulla(middle region)functions as mycollecting chamber.

• The renal pelvis(inner region) re-ceives urine throughthe major calyces.

845509.qxd 8/19/08 5:40 PM Page 199

and RBC-free filtrate into the tubular system of thenephron. (See A look at a nephron.)

A tireless inner tubeThis tubular system has three parts through which the fil-trate passes in succession:• The proximal convoluted tubules, along withglomeruli, are located in the cortex of the kidney. Thispart of the nephron has freely permeable cell membranesthat allow glucose, amino acids, metabolites, and elec-

200URINARY SYSTEM

The illustration below shows the structures of the kidney, whichplays a major role in the elimination of wastes and excess ions(in urine); blood filtration; acid-base, electrolyte, and blood pres-sure regulation; and blood cell formation.


Major structures of the kidney

Renal pyramid

Renal calyx(KAY-LIKS)Renal artery

Renalvein

Renal pelvis

Medulla(MEH-DOOL-UH)Cortex

Ureter(YOU-REE-TUHR)

845509.qxd 8/19/08 5:40 PM Page 200

trolytes from the filtrate to pass into nearby capillariesand back into the circulatory system.• The loop of Henle, which forms the renal pyramid inthe medulla, is a U-shaped continuation of the renaltubule. In the descending loop more water is removedfrom the filtrate; in the ascending part, sodium and chlo-ride are removed to maintain osmolality.• The distal convoluted tubule, like the proximaltubule, is located in the cortex. In the distal tubule, moresodium and water are removed as potassium and hydro-gen ions and ammonia are introduced.

The distal end joins the distal end of other nephrons.Their concentrated filtrate, now urine, flows into largercollecting tubules. These tubules arch back into the


The illustration below shows the structures of the nephron,which performs resorption and secretion of ions and mechanicalfiltration.


A look at a nephron

Proximal convoluted tubule

Bowman’scapsule

Glomerulus(GLAWH-MER-YUH-LUHS)

Collecting tubule

Loop of Henle(HEN-LEH)

My job

is really

draining.

845509.qxd 8/19/08 5:40 PM Page 201

medulla as part of the renal pyramids and empty theurine into the calyces.

It’s a hormone thingHormones help regulate tubular reabsorption and secre-tion. For example, antidiuretic hormone (ADH) actsin the distal tubule and collecting ducts to increase waterreabsorption and urine concentration.

Remember reninBy secreting the enzyme renin, the kidneys play a crucialrole in regulating sodium retention and, therefore, bloodpressure and fluid volume. This regulation takes placemostly through a complicated cascade of events in therenin-angiotensin system. (See Two - in words.)

In the liver, renin converts the substance an-giotensinogen to angiotensin I. Traveling to the lungs,angiotensin I is converted to angiotensin II, a potentvasoconstrictor that acts on the adrenal cortex to stimu-late the production of the hormone aldosterone.

Retention regulationAldosterone affects tubular reabsorption by regulatingsodium retention and helping control potassium secre-tion in the tubules. When serum potassium levels rise, theadrenal cortex responds by increasing aldosterone secre-tion. Increased aldosterone levels increase sodium andwater retention and depress the formation of more renin.

202URINARY SYSTEM

The words renin and angiotensin both end with the suffix -in,

which derives from Latin and means of or belonging to.

Ren- and angiotens-

As in the word renal, the renin renin indicates the kidneys; theword literally means related to the kidneys. Angio- derives fromGreek and means blood vessel; tens comes from Latin tensum,

meaning stretched. The word angiotensin thus means relating tothe stretching (or tension) imposed on blood vessels, which ismeasured as blood pressure.


Two -in words

845509.qxd 8/19/08 5:40 PM Page 202

RBC productionLow levels of oxygen in the arterial blood tell the kidneysthat the body needs more RBCs to deliver oxygen to thetissues. In response, the kidneys secrete a hormonecalled erythropoietin, which travels to the bone mar-row and stimulates increased RBC production.

BladderEach kidney has a ureter, a tube that carries urine byperistalsis from the kidney to the bladder, a hollow,sphere-shaped, muscular organ in the pelvis that storesurine. Urination results from involuntary (reflex) andvoluntary (learned or intentional) processes. Whenurine fills the bladder, parasympathetic nerve fibers inthe bladder wall cause the bladder to contract and the in-ternal sphincter to relax.

You can relax nowThis parasympathetic response is called the micturitionreflex. The cerebrum then stimulates voluntary relax-ation and contraction of the external sphincter of thebladder, causing urine to pass into the urethra for elimi-nation from the body.

UrethraThe urethra is a small duct that channels urine outsidethe body from the bladder. (See The urinary tract, page204.)

FemalesIn the female, the urethra is embedded in the anteriorwall of the vagina behind the symphysis pubis (the bonyprominence under the pubic hair). The urethra connectsthe bladder with an external opening called the urethralmeatus, located anterior to the vaginal opening.

MalesIn the male, the urethra passes vertically through theprostate gland, then extends through the urogenitaldiaphragm (a triangular ligament) and the penis. Themale urethra serves as a passageway for semen as well asurine.


Get ready for

reabsorption!

Okay!

845509.qxd 8/19/08 5:40 PM Page 203


Examining a patient’s urinary system requires observa-tion, palpation, and keen interviewing skills. Before youcan perform a complete physical examination, you mustknow these essential urinary system terms:• Anuria is the absence of urine production. Anuria mayalso refer to absence of urine output (the body producesurine but can’t eliminate it).• Azotemia, or uremia, refers to accumulation of ex-cess amounts of nitrogenous bodies, particularly urea, inthe blood.

204URINARY SYSTEM

The illustration below shows the structures of the urinary tract.


The urinary tract

Inferior vena cava

Right adrenal gland

Right kidney

Right renal artery and vein

Right ureter(YOU-REE-TUHR)

Left adrenal gland

Left kidney

Aorta

Left ureter

Urinary bladder

845509.qxd 8/19/08 5:40 PM Page 204

• Dysuria is painful or difficult urination.• Enuresis refers to nighttime urinary incontinence in agirl older than age 5 or boy older than age 6.• Glycosuria is the abnormal presence of glucose in theurine.• Hematuria is the presence of blood in the urine.• Nocturia refers to excessive urination at night.• Oliguria is diminished urine production in relation tofluid intake, usually less than 400 ml in 24 hours.• Polyuria is excessive production of urine.• Proteinuria refers to the presence of protein in theurine.• Pyuria is pus in the urine.• Renal colic is sharp, severe pain occurring in the low-er back, radiating forward into the area of the groincaused by kidney stones.• Thornton’s sign is severe flank pain resulting fromkidney stones.• Urinary hesitancy is difficulty beginning urinationand subsequent decreased urine flow.• Urinary incontinence refers to a loss of control overbladder and urethral sphincters, resulting in involuntaryleakage of urine.• Urinary tenesmus is persistent, ineffective, painfulstraining to empty the bladder.• Urine retention is retaining urine in the bladder.

Diagnostic tests

Here are common diagnostic tests for patients with uri-nary system disorders.

Urine and bladder testsThe following urine and bladder tests provide the mostdirect assessment of urinary function:• Cystometry assesses the bladder’s neuromuscularfunction, including bladder sensation, capacity, and thepresence or absence of detrusor muscle contractions. Acystometer is the instrument used to measure theamount, flow, and time of voiding.

205DIAGNOSTIC TESTS

Look! Many of

these words have a

common root—uria.

It comes from the

Greek word ouron,

which means urine.

845509.qxd 8/19/08 5:40 PM Page 205

• External sphincter electromyography evaluates uri-nary incontinence by measuring electrical activity of theurinary sphincter muscle.• 24-hour urine specimen collects urine over a 24-hourperiod to determine levels of the following:– creatinine, a nitrogenous waste product produced byworking muscle tissue and normally excreted in the urine– protein, normally absent from urine– uric acid, an end product of protein metabolism nor-mally excreted in the urine.• Urea clearance measures urine levels of urea, thechief end product of protein metabolism. This test mea-sures glomerular filtration rate (GFR), but is less reli-able than the creatinine clearance.• Urinalysis tests the urine for color, turbidity, specificgravity, pH, protein, glucose, and ketone bodies. This testalso examines sediment for blood cells, casts, and crys-tals.• Urine culture checks for bacterial growth in the urine,which indicates urinary tract infection (urine is normallysterile).• Urine myoglobin detects the presence of myoglobin,a red pigment found in the cytoplasm of cardiac andskeletal muscle that is excreted in the urine as a result ofmuscle injury.• Urine osmolality is the concentration or osmoticpressure of urine expressed in milliosmols per kilogramof water.• Uroflowmetry measures the volume of urine expelledfrom the urethra in milliliters per second (urine flowrate) and also determines the urine flow pattern. Abnor-mal results can indicate obstruction of the urethra.

Blood studiesHere are several blood tests used to diagnose urinary dis-ease and evaluate kidney function:• Anion gap is the measurement of the total concentra-tions of anions and cations in the blood. An increased an-ion gap is present with renal failure.• Blood urea nitrogen level measures the amount ofserum nitrogenous urea. Levels are elevated with kidneyfailure and dehydration.

206URINARY SYSTEM

The glom- of

glomerular derives

from the Latin word

glomus, meaning ball,

and is akin to the

Latin globus, meaning

globe.

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• Calcium and phosphorus levels indicate the kidney’sefficient conversion of vitamin D to a metabolite essen-tial for calcium absorption in the intestines.• Chloride tests measure serum levels of chloride,which helps regulate blood pressure and acid-base bal-ance, and is excreted by the kidneys.• Creatinine clearance assesses the GFR by measuringhow well the kidneys remove creatinine from the bloodover a 24-hour period. This test is an excellent indicatorof renal function because it requires blood and urinespecimens.• Serum creatinine measures blood levels of creati-nine. Creatinine levels are elevated with renal damage.• Serum osmolality tests the concentration of serumexpressed in milliosmols per kilogram of water.• Serum potassium levels measure blood potassium,essential for proper renal functioning.• Serum sodium levels are evaluated in relation to theamount of water in the body. Abnormal ratios may indi-cate renal disease.• Serum uric acid levels measure uric acid, a normalby-product of metabolism that’s excreted by the kidneys.Levels may be abnormally high with gout or impaired re-nal function. Below-normal levels may indicate problemswith renal tubular absorption.

Radiologic and imaging testsHere are the names of radiologic, tomographic, sono-graphic, and endoscopic diagnostic procedures:• Computerized tomography (CT) scan generates athree-dimensional, computerized image of the kidneys.This test is useful in detecting kidney stones.• Cystourethroscopy uses an endoscopic instrument toexamine the bladder, bladder neck, and urethra. (SeeShow me a cystoscope, page 208.)• Excretory urography, also known as I.V. pyelogra-phy, injects a radiopaque contrast medium to visualizerenal structures, ureter, bladder, and the urethra. (SeeIVP in action.)• Kidney-ureter-bladder (KUB) X-ray is just that, anX-ray of the kidneys, ureter, and bladder.• Magnetic resonance imaging (MRI) creates precisethree-dimensional (tomographic) images of tissue bypassing magnetic energy through the body.

207DIAGNOSTIC TESTS

IVP in action

In practice, you’ll hearexcretory urography re-ferred to as an IVP, anabbreviation for an oldername of the test, intra-venous pyelography. Forexample, you might hearsomeone say, “We needto take the patient for anIVP to check for an ob-struction in the ureter.”

The realworld

845509.qxd 8/19/08 5:40 PM Page 207

• Nephrotomography creates a tomogram of the kid-neys after I.V. injection of a contrast medium.• Radionuclide renal scan requires injecting a ra-dionuclide (radioactive material) before scintigraphy,which records the relative distribution of radioactivity inthe tissues and, therefore, proper functioning of those tis-sues.• Renal angiography creates X-ray images of renal arte-rial circulation after the injection of a contrast mediuminto the aorta and renal arteries.• Renal venography creates X-ray images of the kid-neys by injecting a contrast medium into a vein.• Retrograde cystography instills a contrast mediuminto the bladder, followed by radiographic examination.• Ultrasonography visualizes the urinary system bymeasuring and recording the reflection of pulses of ultra-sonic waves directed into the tissue.• Voiding cystourethrography demonstrates the effi-ciency of bladder filling and excretion by instilling a con-trast medium into the patient’s bladder through a urinarycatheter. Radiographs are then taken before, during, andafter voiding. (See Cystourethrography.)

208URINARY SYSTEM

Show me a cystoscope

This illustration shows a cys-toscope being insertedthrough the male urethrainto the bladder. A cysto-scope can be used for visualexamination of the bladderor to remove tumors. Cystoscope

Water cord

Urinary bladderProstate gland

Rectum

Light cord

Cystourethrog-raphy

In cystourethrography

the prefix cysto- is theGreek word element forbladder. Urethro refersto the urethra and -gra-

phy is a method ofrecording. Thus, cysto-urethrography is a pro-cedure that records(through radiography)bladder and urethrafunction.


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Disorders

This section covers disorders of the urinary system, in-cluding varieties of acute renal failure and other disor-ders.

Acute renal failureAcute renal failure is the sudden interruption of renalfunction, caused by obstruction, poor circulation, or kid-ney disease. Types of this potentially life-threatening con-dition are classified by the cause of onset:• Intrarenal failure, also called intrinsic orparenchymal renal failure, results from damage to thekidneys’ filtering structures.• Postrenal failure results from obstruction of urineoutflow.• Prerenal failure is caused by any condition that re-duces blood flow to the kidneys (hypoperfusion).

Stages of acute renal failureEach type of acute renal failure has three distinct phases:• The oliguric phase is marked by decreased urine out-put (less than 400 ml in 24 hours).• The diuretic phase occurs when the kidneys producea high volume of urine.• The recovery phase occurs when the cause of diuresisis corrected, azotemia gradually disappears, and the pa-tient begins to improve.

Other disorders• Acute poststreptococcal glomerulonephritis is arelatively common inflammation of the glomeruli after astreptococcal infection of the respiratory tract.• Acute pyelonephritis is a sudden inflammation of thekidney and its pelvis caused by bacteria.• Acute tubular necrosis (ATN), also called acutetubulointerstitial nephritis, destroys the tubular seg-ment of the nephron, leading to renal failure and uremia.• Alport’s syndrome is a hereditary kidney inflamma-tion in which the patient may have recurrent gross or mi-croscopic hematuria.

209DISORDERS

I can’t work

without a

blood supply.

845509.qxd 8/19/08 5:40 PM Page 209

• Benign prostatic hyperplasia occurs when theprostate gland enlarges enough to compress the urethra,causing urinary obstruction.• Chronic glomerulonephritis is an inflammation ofthe glomerulus of the kidney characterized by decreasedurine production, blood and protein in the urine, and ede-ma.• Chronic renal failure is the typically slow, progres-sive loss of kidney function and glomerular filtration.• Cystitis refers to inflammation of the bladder, usuallycaused by an ascending infection.• Cystocele is a herniation of the urinary bladderthrough the vaginal wall. (See Cystocele is all Greek.)• Fanconi’s syndrome is a kidney disorder that pro-duces malfunctions of the proximal renal tubules, leadingto elevated potassium levels, elevated sodium levels, glu-cose in the urine and, eventually, rickets and retardedgrowth and development.• Hydronephrosis refers to a distention of the kidneysby urine that’s caused by obstruction of the ureter.• Hypospadias is a condition in which the urethra open-ing is on the ventral surface of the penis. This conditionrarely occurs in females, where the opening occurs with-in the vagina.• Nephrotic syndrome is a condition marked by pro-teinuria, low blood albumin levels, and edema.• Neurogenic bladder refers to any dysfunction of thenerves that control the bladder. The patient’s bladder be-comes spastic or flaccid, and urinary incontinence re-sults.• Polycystic kidney disease is characterized by multi-ple cysts of the kidney.• Prostatitis, an inflammation of the prostate gland,may be acute or chronic.• Renal calculi are kidney stones that form from min-erals normally dissolved in the urine, such as calcium ormagnesium.• Renovascular hypertension is hyperten-sion that occurs as a result of partial blockageof one or both renal arteries. An excessive re-lease of the enzyme renin occurs, which ulti-mately produces vasoconstriction and hyper-tension.

210URINARY SYSTEM

Skipping

stones. Great!

Having stones

inside me. Ouch!

Cystocele is allGreek

Cystocele is an easyword. Cysto- comes fromthe Greek word kystis,

which means bladder orpouch. Cele- is also de-rived from a Greek word,kele, which means her-nia.


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• Renal infarction occurs when a thrombus or emboluscauses ischemia of a kidney.• Renal vein thrombosis is clotting in the renal veinthat results in renal congestion, engorgement and, possi-bly, infarction.• Ureterostenosis is a ureteral stricture.• Urethritis is inflammation of the urethra.• Vesicoureteral reflux is a condition in which urineflows from the bladder back into the ureters and eventu-ally into the renal pelvis or the parenchyma.

Treatments

Noninvasive procedures, dialysis, and surgeries that treatdisorders of the urinary and renal systems are describedhere.

LithotripsyThere are two procedures that use a process calledlithotripsy to reduce the size of renal calculi:• Extracorporeal shock-wave lithotripsy (ESWL) isa noninvasive treatment that breaks up calculi with high-energy shock waves to allow their passage out of thebody.• Percutaneous ultrasonic lithotripsy uses an ultra-sonic probe inserted through a nephrostomy tube intothe renal pelvis. The probe generates ultrahigh-frequencysound waves that shatter calculi and continuous suction-ing removes the fragments.

CathetersCatheters are used in several ways to treat urinary sys-tem disorders:• An external catheter, also called a Texas or condomcatheter, is a urine collection device that fits over the pe-nis and resembles a condom.• An indwelling urinary catheter is a urinary catheterwith a balloon end designed to remain in the urinarybladder for a prolonged time. (See Don’t fool with myFoley.)

211TREATMENTS

Don’t fool withmy Foley

You may hear an in-dwelling urinary catheterreferred to as a Foley,named after Dr. Freder-ick Foley, the Americandoctor who designed thedevice.

The realworld

845509.qxd 8/19/08 5:40 PM Page 211

• An intermittent catheterization is a procedure thatdrains urine remaining in the bladder after each voidingor as needed for those who can’t void.

DialysisDialysis is a technique for removing waste products fromthe body when the kidneys fail. Several types of dialysisare explained here:• Continuous ambulatory peritoneal dialysis(CAPD) is a form of peritoneal dialysis that allows thepatient to continue daily activities.• Continuous arteriovenous hemofiltration (CAVH)filters toxic wastes from the patient’s blood and infuses areplacement solution such as lactated Ringer’s solution.• Continuous arteriovenous ultrafiltration (CAVU)uses equipment similar to that in CAVH but removes fluidfrom the patient’s blood at a slower rate.• Continuous-cycling peritoneal dialysis (CCPD)uses a machine to perform dialysis at night while the pa-tient sleeps, and the patient performs CAPD in the day-time.• Hemodialysis filters toxic wastes and other impuritiesdirectly from the blood of a patient with renal failure.Blood is pumped through a dialyzing unit to removetoxins and is then returned to the body.• Peritoneal dialysis removes toxins from the patient’sblood by using the peritoneal membrane surrounding theabdominal cavity as a semipermeable dialyzing mem-brane. In this technique, a dialyzing solution (dialysate)is instilled through a catheter inserted into the peritonealcavity. By diffusion, the dialysate draws excessive con-centrations of electrolytes and toxins through the peri-toneal membrane. Next, excess water is drawn throughthe membrane. After an appropriate dwelling time, thedialysate is drained, taking toxins and wastes with it.

SurgeryCommon surgical procedures to correct urinary systemdisorders include:• Cystectomy is the partial or total removal of the uri-nary bladder and surrounding structures. Cystectomymay be partial, simple, or radical:

212URINARY SYSTEM

Dialysisderives from a

Greek word

meaning

separation. The

medical process

separates toxins

from the blood.

845509.qxd 8/19/08 5:40 PM Page 212

– A partial cystectomy, also called segmental cystec-tomy, involves resection (removal) of only canceroustissue within the bladder. The patient’s bladder functionis usually preserved.– A simple, or total, cystectomy involves resection ofthe entire bladder, but surrounding structures aren’t re-moved.– A radical cystectomy removes the bladder,prostate, and seminal vesicles in men. The bladder,urethra, uterus, fallopian tubes, ovaries, and a seg-ment of the vaginal wall are removed in women.• Cystotomy uses a catheter, which is insertedthrough the patient’s suprapubic area into the blad-der to temporarily divert urine away from the ure-thra and into a closed collection chamber.• Kidney transplantation is one of the most com-mon and successful organ transplant surgeries. Thistreatment is an alternative to dialysis for patientswith end-stage renal disease.• Marshall-Marchetti-Krantz operation helps correcturinary incontinence in female patients by restoring aweakened urinary sphincter.• Prostatectomy is surgical removal of the prostategland to remove diseased or obstructive tissue and re-store urine flow through the urethra. One of four ap-proaches is used:– Radical perineal prostatectomy approaches theprostate through an incision in the perineum between thescrotum and the rectum.– Retropubic prostatectomy uses a low abdominal inci-sion to approach the prostate without opening the pa-tient’s bladder.–Suprapubic prostatectomy uses an abdominal ap-proach to open the bladder and remove the prostate gland.– Transurethral prostatectomy approaches theprostate gland through the penis and bladder, using a sur-gical instrument called a resectoscope. The scope hasan electric cutting wire to remove tissue. This procedureis also called a transurethral resection of theprostate (TURP).• Transurethral resection of the bladder (TURB) isa relatively simple procedure that uses a cystoscope toremove small lesions from the bladder.

213TREATMENTS

I spy two more

words derived from

the Greek word for

bladder: cystectomy

and cystotomy!

845509.qxd 8/19/08 5:40 PM Page 213

• Urinary diversion is a procedure that provides an al-ternative route for urine excretion when the normalchannels are damaged or defective. Several types of uri-nary diversion surgery are performed. (See Two types ofurinary diversion.)– The ileal conduit diverts urine through a segment ofthe small bowel (ileum), which is removed for this pur-pose. A stoma formed on the abdominal wall continuallyempties urine into a collection bag.– A continent vesicostomy allows urine to be divertedto a reservoir constructed from a portion of the bladderwall. A stoma is formed, and accumulated urine can bedrained by inserting a catheter into the stoma.– In a ureterostomy, one or both ureters are dissectedfrom the bladder and brought to the skin surface to formone or two stomas that continuously drain urine.

214URINARY SYSTEM

Two types of urinary diversion

Cystostomy

A cystostomy is a urinary diversion createdwhen a catheter is inserted through the supra-pubic area into the bladder. Urine is divertedaway from the urethra.

Nephrostomy

A nephrostomy is a urinary diversion createdwhen a catheter is inserted through the flankand into the renal pelvis. Urine is diverted awayfrom the bladder.

845509.qxd 8/19/08 5:40 PM Page 214


Vocabulary builders

Across

9. Bacterial kidney infection12. Analysis of urine13. Artery that brings blood to thekidney15. Kidney stones16. Blood in the urine18. Phase of renal failure when kid-neys produce high volumeof urine

19. Structure that collects andholds urine20. Structure through which urineexits the body21. Hormone involved with bloodpressure

Down

1. Study of the renal system2. Protein in the urine3. Inflammation of the prostategland4. Syndrome resulting from ahereditary kidney inflammation5. Network of capillaries6. Striated wedges in the renalmedulla

7. Technique for removing wasteproducts when kidneys fail8. Herniation of the bladder10. Scant urine output11. Bladder infection14. Difficult urination17. Structure that carries urinefrom kidney to bladder


1 2 3 4

5

6 7

8

9

10

11 12

13 14

15

16 17

18 19

20

21

At a crossroadsCompleting this crossword puzzle will help you filter throughurinary system terms. Good luck!

Some

workout,

huh?

845509.qxd 8/19/08 5:40 PM Page 215

216URINARY SYSTEM

Match gameMatch each of the urinary system terms below with its definition.


Finish lineFill in the blanks below with the word that correctly matches the definition for eachurinary system disorder, treatment, or test.

1. Inflammation of the bladder is called ________.

2. Inflammation of the renal glomeruli without infection is called ______.

3. The severe pain caused by kidney stones is called renal _______ .

4. Kidney stones are also called renal _______.

5. A coagulated, necrotic area in the kidney caused by occlusion of blood vessels is

called renal ________.

6. The phase of acute renal failure marked by decreased urine output is the _______

phase.

7. The phase of acute renal failure marked by excess urine output is called the _______

phase.

8. The initials IVP stand for ________.

Clues

1. Catheter that’s left in place ____

2. External catheter ____

3. Used for bladder training ____

4. Uses the peritoneal membrane ____

5. Uses blood ____

6. Dialyzing solution ____

7. Surgical removal of the prostate gland ____

8. Bladder surgery ____

9. Ureters brought to the skin surface ____

10. Diverts urine through small bowel ____

Choices

A. Dialysate

B. Ureterostomy

C. Peritoneal dialysis

D. Cystectomy

E. Indwelling catheter

F. Strengthening exercises

G. Ileal conduit

H. Condom catheter

I. Prostatectomy

J. Hemodialysis

Match the

words to their

definitions up

top, and fill in

the blanks

down below.

845509.qxd 8/19/08 5:40 PM Page 216




1.

2.

3.

4. Got it!

845509.qxd 8/19/08 5:40 PM Page 217

218URINARY SYSTEM

1. E; 2. H; 3. F; 4. C; 5. J; 6. A; 7. I; 8. D; 9. B; 10. G

Match game

1. Cystitis; 2. Glomerulonephritis; 3. Colic; 4. Calculi; 5. Infarction;6. Oliguric; 7. Diuretic; 8. Intravenous pyelography

Finish line

1. Pyuria; 2. Cystourethroscopy; 3. Calyx; 4. Henle

O see, can you say?

At a crossroads

Answers

1N

2P

3P

4A

E R5G R L

P O L O P6P

7D

H T O S O Y I

R E M T R R A8C O I E A T A L

9P Y E L O N E O H R I T I S M Y

S O U U I I S

T G R L T10O D I

O Y I11C

12U R I N A L Y S I S

C A Y S S I13R E N A L S G

14D

L T15C A L C U L I Y

16H E M A T

17U R I A R S

R T I U18D I U R E T I C

19B L A D D E R

T S I

E20U R E T H R A

21R E N I N

845509.qxd 8/19/08 5:40 PM Page 218

C9INCREDIBLY EASY MINIGUIDE: THE KIDNEY

Incredibly Easy miniguide: The kidney

The kidney is a bean-shaped organ. The right kidney may be lower than the left because the liver crowds it in the abdominal cavity.

Filtered blood returns to thecirculation by way of the renal

vein, which empties into theinferior vena cava.

The kidney receiveswaste-filled blood from

the renal artery.

The

kidney is

part of

the body’s

filtration

system.

8455CP3.qxd 8/19/08 8:05 PM Page C9



Each kidney has three regions: the renal cortex, the renal medulla, and the renal pyramids.

Left kidney cross section The renal medulla (middle region)contains eight to ten renal pyramids—

striated wedges that are composedmostly of tubular structures. The tapered

portion of each pyramid empties into acuplike calyx.

The renal cortex

(outer region)contains blood-

filtering mechanismsand is protected by afibrous capsule and

layers of fat.

The renal pelvis receivesurine from the pyramids

through the calyces (plural ofcalyx). It’s the expanded

proximal end of the ureter.

There are six toeight renal pyramids,

or lobes, per kidneythat act as collecting

ducts for urine.

8455CP3.qxd 8/19/08 8:05 PM Page C10

C11INCREDIBLY EASY MINIGUIDE: THE KIDNEY


The nephron is the functional and structural unit of the kidney. It’s responsible for selective reabsorption of ions and the mechanicalfiltration of fluids, wastes, electrolytes, and acids and bases.

The nephron

The distal convoluted

tubule reabsorbs sodiumunder the influence of

aldosterone.

The proximal convoluted

tubule reabsorbs glucose, aminoacids, metabolites, and electrolytes

from filtrate.

The collecting tubule is thedistal end of the nephron. Here, thefinal fluid concentration takes placeand empties into the papillary ducts.

Each kidney

contains about

1.25 million

nephrons.

The loop of Henle

maintains osmolalityby removing sodiumand chloride; it alsoremoves water from

the filtrate.

8455CP3.qxd 8/19/08 8:05 PM Page C11



The concentrated filtrate(urine) flows into the collecting

tubules that empty urine intothe calyces.

The proximal tubule allows glucose,amino acids, metabolites, and electrolytes topass from the filtrate into the capillaries and

back into the circulatory system.

The enclosed end of the nephron is called Bowman’s capsule.

Bowman’s capsule

contains a cluster of capillaries,called the glomerulus, that acts

as a bulk filter.

My job is

really

draining!

8455CP3.qxd 8/19/08 8:05 PM Page C12

Reproductive structure and function

Essential terminology related to the structure and normalfunction of the male and female reproductive systemsand associated organs is presented here. A clear under-standing of these systems will help you remember the ter-minology. (See Pronouncing key reproductive systemterms, page 220.)

Male reproductive systemThe male reproductive system consists of the organs thatproduce, transfer, and introduce mature sperm into thefemale reproductive tract, where fertilization occurs.In addition to producing male sex cells, the male repro-ductive system secretes some of the male sex hormones.The male reproductive organs include the penis, scrotumand testes, duct system, and accessory reproductiveglands.

10

Health assessmentReproductive system

Just the facts


♦ terminology related to the structure and function ofthe reproductive system

♦ terminology needed for physical examination

♦ tests that help diagnose common reproductive dis-orders

♦ reproductive system disorders and their treatments.

The male

reproductive

system

produces sperm

and some male

sex hormones.

845510.qxd 8/19/08 5:55 PM Page 219

PenisThe penis deposits sperm (mature male germ cells) intothe female reproductive tract through copulation andacts as the terminal duct for the urinary tract.

Column3

The cylindrical penile shaft contains three columns ofspongy vascular tissue that respond to sexual stimulationby becoming engorged with blood. Two of the threecolumns of this erectile tissue are bound together byheavy fibrous tissue and form the corpora cavernosa,the major part of the penis. The third column, on the un-derside of the shaft, is called the corpus spongiosum. Itencases the urethra. (See Caves and sponges.)

So sensitiveThe glans penis, at the distal end of the shaft, is a cone-shaped structure formed from the corpus spongiosum. Itslateral margin forms a ridge of tissue known as the coro-na. The glans is highly sensitive to sexual stimulation.

220REPRODUCTIVE SYSTEM

Below is a list of key terms related to the reproductive systemsalong with the correct ways to pronounce them.


Pronouncing key reproductivesystem terms

Adnexa

Ballottement

Dyspareunia

Epididymis

Gonadotropin

Leydig’s cells

Oophorectomy

Symphysis pubis

ADD-NEK -SUH

BAHL-OT-MAW

DIS-PEH-ROO-NEE-UH

EP-UH-DID-UH-MISS

GOH-NEH-DOH-TROH-PIN

LAY-digz SELLZ

OH-OFF-UH-REK-TOH-MEE

SIM-FUH-SIS PYOU-BIS

845510.qxd 8/19/08 5:55 PM Page 220

Nearest exitThin, loose skin covers the penile shaft. The urethralmeatus opens through the glans to allow urination andejaculation. (See Structures of the male reproductivesystem, page 222.)

Scrotum and testesThe scrotum, meaning pouch, contains the primary malesex organs and joins with the penis at the penoscrotaljunction. A thin layer of skin covers the scrotum, overly-ing a tighter, muscular layer. Within the scrotum are twosacs that each contain a testis, an epididymis, and a sper-matic cord. The seam where the two sacs join is calledthe median raphe and is visible on the exterior of thescrotum. (See The rap on the median raphe, page 223.)

Totally tubularThe testes, also called the testicles, are two egg-shapedglands within the scrotum. Enclosed in a fibrous whitecapsule, each testicle is divided into numerous compart-ments, or lobules. The lobules contain seminiferoustubules, where spermatogenesis (sperm formation)takes place. This begins when a male reaches pubertyand continues throughout life. Stimulated by male sexhormones, sperm continuously form within these tubules.

221REPRODUCTIVE STRUCTURE AND FUNCTION

The terms corpora cavernosa and corpus spongiosum describethe columns of spongy vascular tissue in the penile shaft that re-spond to sexual stimulation.

Latin roots

Corpora is simply the plural of corpus, a Latin word for the mainpart of a bodily structure. Cavernosa is a cave or cavity. Spon-

giosum relates to a sponge, which is made up of little cavities.


Caves and sponges

845510.qxd 8/19/08 5:55 PM Page 221

Duct systemThe male reproductive system includes a complicated ductsystem that delivers sperm from the testes to the ejacula-tory ducts near the bladder. This system consists of theepididymides, the vas deferens, and the ejaculatory ducts.


The male reproductive system consists of the penis, the scrotum and its contents, the prostate gland, and the inguinal structures.These structures are illustrated below.


Structures of the male reproductive system

Urinary bladder

Rectum

Seminal vesicle

Prostate gland

Ejaculatory duct

Anus

Epididymis

Testis

Scrotum

Urethral meatus

Internal inguinal ring(IN-GWIN-UHL)

Symphysis pubis

External inguinal ring

Vas deferens

Corpus spongiosum(KOR-PUHSSPUHN-GEE-OH-SUHM)Urethra

Corpus cavernosum

Corona

Prepuce(PREE-PYOUS)

Glans penis

845510.qxd 8/19/08 5:55 PM Page 222

Riding the epididymidesThe epididymides (singular: epididymis) are coiled,tubular reservoirs that store sperm before ejaculation, se-crete some of the seminal fluid, and serve as passage-ways for sperm. One epididymis is located along the bor-der of each testicle.

Bundle of nervesMature sperm travel from the epididymis to the vas def-erens, or ductus deferens. These two tubes begin at theepididymides, pass through the inguinal canal (formedby the pelvic girdle), and enter the ejaculatory duct insidethe prostate gland. Each vas deferens is enclosed by aspermatic cord, a compact bundle of vessels, nerves,and muscle fibers.

Ready for dischargeThe ejaculatory ducts are two short tubes formed bythe vas deferens and the ducts of the seminal vesicles.They pass through the prostate gland and enter the ure-thra. The seminal vesicles, two pouches located alongthe bladder’s lower edge, produce most of the liquid partof semen (the thick, whitish secretion that’s dischargedduring ejaculation). The seminal vesicles also produceprostaglandins, potent hormonelike fatty acids.

Prostate glandThe walnut-sized prostate gland is located under thebladder and surrounds the urethra. It conists of three lob-ules: the left and right lateral lobes and the median (mid-dle) lobe. These lobules continuously secrete prostaticfluid—a thin, milky substance that comprises about one-third of the semen volume and activates the sperm.

HormonesMale sex hormones, called androgens, are produced inthe testes and adrenal glands.


The rap on themedian raphe

The seam where the twoscrotal sacs join, calledthe median raphe, is visi-ble on the exterior of thescrotum. Median comesfrom the Latin term me-

dianus, meaning in themidline of a structure.Raphe is the Greek wordfor seam.


Doctors used

to think it was

produced in the

prostate gland.Think prosta +

gland + in.

How did

prostaglandinget its name?

845510.qxd 8/19/08 5:55 PM Page 223

It takes testosteroneInterstitial cells, called Leydig’s cells, are found in tissuebetween the seminiferous tubules (the tubules thatproduce and conduct sperm). Leydig’s cells secretetestosterone, the most important male sex hormone. Aman’s body needs testosterone for development of thesex organs, secondary sex characteristics (such as facialhair), and sperm formation.

Two other hormones—luteinizing hormone (LH),also known as interstitial cell–stimulating hormone,and follicle-stimulating hormone (FSH)—directly af-fect testosterone secretion.

Female reproductive systemThe ovaries are the basic organs of female reproduction.Internal and external female reproductive organs includethe fallopian tubes, uterus, vagina, and mammary glands.

External structuresAs in males, the mons pubis in females is a triangularpad of tissue that’s covered by skin and pubic hair and islocated over the symphysis pubis, the joint formed bythe union of the pubic bones.

Just for herThe external female genitals, sometimes referred to asthe pudendum, are contained in the region called thevulva. (See Addendum on the pudendum.)

Two labia majora form the sides of the vulva. Thelabia minora, two moist mucosal folds, lie within andalongside the labia majora.

The perineum consists of muscles, fasciae, and liga-ments between the anus and vulva. (See External struc-tures of the female reproductive system.)

Small, but importantThe clitoris is a small, erectile organ located at the ante-rior of the vulva. Less visible are the multiple openings ofSkene’s glands, mucus-producing glands found on bothsides of the urethral meatus. Bartholin’s glands, othermucus-producing glands, are located on each side of andbehind the vaginal opening. The hymen, a tissue mem-


Addendum onthe pudendum

The term pudendum de-rives from the Latin wordpudendus. This means,literally, that of whichone is to be ashamed. Inlate classical and Latinand early Christian writ-ings, the word came torefer to the external gen-italia of both sexes. Now,it more commonly refersto just female genitalia.


845510.qxd 8/19/08 5:55 PM Page 224

brane varying in size and thickness, can sometimes com-pletely cover the vaginal opening.

Internal organsThe vagina is a highly elastic muscular tube located be-tween the urethra and the rectum. A mucous membranelining lubricates the vagina during sexual activity. Rugae,folds of tissue in the vaginal walls, allow the vagina tostretch. (See Internal structures of the female reproduc-tive system, page 226.)


This illustration shows the structures of the female reproductive system that are visible externally.


External structures of the female reproductive system

Mons pubis

Clitoris(KLIT-UH-RIS)

Labia majora

Skene’s duct opening

Labia minora

Bartholin’s glands

Urethral meatus

Vaginal orifice(VAJ-UH-NUHL)

Perineum(PER-I-NEE-UHM)

Anus

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The pear-fect uterusThe vagina leads to the uterus, a small, firm, pear-shapedmuscular organ resting between the bladder and rectum.The uterus usually lies at a 90-degree angle to the vagina.


These illustrations provide a lateral and anterior cross-sectional view of the internal structures of the female reproductive system.


Internal structures of the female reproductive system

Ovary

Uterine neck

Cervix(SER-VIKS)

Rectum

Anus

Fallopian tube

Fimbria

Ovary

Uterine neck

Vagina

Fallopian tube(FUH-LOH-PEE-UHN)

Corpus of uterus

Fundus of uterus

Bladder

Symphysis pubis

Urethra

Vagina

Fundus of uterus

Corpus of uterus

Endometrium

Myometrium

Cervix

Lateral view of internal genitalia

Anterior cross-sectional view of internal genitalia

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The mucous membrane that lines the uterus is called theendometrium. The muscular layer is called the myome-trium. (See Metrium matters.)

The uterine neck, or isthmus, joins the upper uterus,or fundus, to the cervix, the part of the uterus that ex-tends into the vagina. The fundus and isthmus make upthe corpus, or main body of the uterus.

Certainly the cervixThe mouth of the cervix is called the os, a Latin term fora body orifice. The internal os opens from the cervixinto the cervical canal, and the external os leads fromthe cervical canal to the vagina. A mucous membranecalled the endocervix lines the cervical canal.

Fundamentally fallopianThe fallopian tubes are a pair of ducts attached to theuterus at the upper angles of the fundus. These long, nar-row, muscular tubes have fingerlike projections, calledfimbriae (pronounced: FIHM-BREE-EE), on their free endsthat partially surround the ovaries. (See Fallopian facts.)

Fertilization of the ovum (egg), or female sex cell,usually occurs in the outer third of the fallopian tube.

Obviously ovarianThe ovaries are two almond-shaped organs. One ovary islocated on each side of the pelvis and is connected to theuterus by a ligament. The main function of the ovaries isto produce mature ova.

At birth, each ovary contains approximately 50,000graafian follicles, mature ovarian vesicles that each


Metrium matters

The mucous membranethat lines the uterus iscalled the endometrium.

The muscular layer iscalled the myometrium.

The root of thesewords, metrium, refersto the uterus. It comesfrom the Greek word me-

ter, which is related toand has the same mean-ing as the English wordmother.


Although the correct function of the fallopian tubes had beenknown for more than 2,000 years, these structures received theirname from Gabrielle Fallopio, a 16th-century Italian surgeon. Hedescribed and named the tubes in his book ObservationesAnatomicae (published in 1562), which corrected a number ofwidely held false ideas about anatomy.


Fallopian facts

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contain an ovum. During childbearing years, one of thesegraafian follicles produces a mature ovum during the firsthalf of each menstrual cycle.

Her hormonesAt puberty, the ovaries release progesterone and the fe-male sex hormone estrogen. They also release a matureegg during the menstrual cycle. When expelled from theovary, ova are caught by the fimbriated ends of the fallop-ian tubes.

The ovarian cycleThe Latin word menstrualis means monthly. The aver-age menstrual cycle occurs over 28 days, roughly 1month. Regulated by fluctuating, reciprocating hormones,this monthly cycle is divided into three phases: menstru-al, proliferative, and luteal.

Phase I—stimulateThe menstrual, or preovulatory, phase begins on thefirst day of menstruation. As the cycle begins, low estro-gen and progesterone levels in the bloodstream stimulatethe hypothalamus to secrete gonadotropin-releasinghormone. In turn, this substance stimulates the anteriorpituitary gland to secrete FSH and LH. When FSH levelrises, LH output increases.

Phase II—proliferate and ovulateThe proliferative, or follicular, phase lasts from day 6to day 14. During this time, LH and FSH act on the ovari-an follicle containing the ovum and stimulate estrogensecretion. After 14 days, estrogen production decreases,the follicle matures, and ovulation occurs. Normally, onefollicle matures and is released from the ovary duringeach cycle.

Luteal phase—going downDuring the luteal phase, which lasts about 14 days, FSHand LH levels drop. Estrogen levels decline at first. Afterthe follicle ruptures and produces progesterone, the yel-low structure called the corpus luteum (Latin for yellowbody) begins to function, and estrogen and progesteronelevels rise.


Mensis is the

Latin word for

month. It’s

closely related to

the English word

moon, which has

a monthly cycle,

too.

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During this phase, the endometrium responds toprogesterone by becoming thicker and preparing to nour-ish a fertilized ovum. About 10 to 12 days after ovulation,the corpus luteum diminishes as progesterone and estro-gen levels drop. When a fertilized ovum isn’t present andhormone levels can’t sustain the thickened endometrium,the lining is shed. The process of shedding the lining isknown as menses.

BreastsThe mammary glands, or breasts, are milk-producingstructures. Breast development is controlled by estrogenand progesterone, hormones secreted by the ovaries.Each breast contains ducts surrounded by acini (milk-secreting cells). Individual ducts join with others to formlarger ducts, which encircle the nipple and end in tinyopenings on the nipple surface. The anterior lobe of thepituitary gland produces a lactogenic hormone calledprolactin to stimulate lactogenesis (milk production).

The areola is the pigmented area (in Latin, the wordmeans a little open space) around the nipple. (See The fe-male breast, page 230.)

MenopauseMost women cease menstruation between ages 40 and 55.The term menopause applies if a menstrual period hasn’toccurred for 1 year. Climacteric refers to a woman’stransition from reproductive fertility to infertility. Thistransitional phase can occur over a period of severalyears and is also referred to as perimenopause.

At the onset of menopause, estrogen and proges-terone levels begin to decrease and testosterone secre-tion increases. The body compensates for estrogen defi-ciency by producing estrone, a weaker form of estrogen.


Lactos is Latin for

milk. Genesis is a

Greek word that

means creation. Put it

together and you can

tell that lactogenesismeans milk

production.

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The female breast

Here’s a closer look at terms related to the female breast.

Structures of the female breast

The areola—the pigmented area in the centerof the breast—contains the nipple. Pigmentederectile tissue in the nipple responds to cold,friction, and sexual stimulation. The interior ofeach breast is composed of glandular and fi-brous tissues. Glandular tissue contains 15 to20 lobes made up of clustered acini, tinysaclike duct terminals that secrete milk. Fi-brous Cooper’s ligaments support the breasts.

Milk production and drainage

Acini draw the ingredients needed to makemilk from the blood in surrounding capillaries.Lactiferous ducts and sinuses store milk duringlactation, conveying it to and through the nip-ples.

Glands on the areolar surface, calledMontgomery’s tubercles, produce sebum thatlubricates the areola and nipple during breast-feeding.

Lateral cross section

Clavicle

Adipose tissue

Acini of lobule

Glandular lobe

Collecting and main ducts

Areola

Montgomery’s tubercle

Nipple

Lactiferous duct orifice

Lactiferous sinus

Lactiferous duct

Take a

closer look at

the body’s

milk-producing

system.

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Here are terms associated with physical examination ofthe male and female reproductive systems:• Anorchism is the absence of one or two testes.• Anovulation is the absence of ovulation• Azoospermia is semen without live sperm.• Ballottement is a physical examination hand manuev-er used to evaluate the shape and size of a deep structureor organ.• Bimanual examination is the palpation of the uterusand ovaries using gloved fingers inside the vagina and theother hand outside of the body on the pelvic area.• Coitus is sexual union.• Detumesence is the subsiding of blood-engorged tis-sue after orgasm.• Digital rectal exam is the examination of the prostateusing a gloved finger inserted into the rectum.• Dysmenorrhea refers to painful menstruation. Thisoccurs at least occasionally in nearly all women. (SeeDissecting dysmenorrhea and more.)• Dyspareunia is a condition in women in which sexualintercourse is difficult or painful.• Frigidity is the lack of sexual response.• Gynecology is the branch of medicine concerned withthe health care of women, including sexual and reproduc-tive functions and diseases of the reproductive organs.


Dysmenorrhea means painful menstruation. The term is easierto remember if you dissect it. Dys- means difficult or painful.Meno literally means monthly and refers to menstruation. Thethird element, -rrhea, another common Greek word element,means flow. So, dysmenorrhea is painful menstrual flow.

One root, many terms

Add a few different letters to meno and you can describe othertypes of menstrual flow, such as:

• amenorrhea (a- means absence; amenorrhea is, thus, an ab-sence of menstrual flow )• menorrhagia (-rhagia derives from a Greek verb meaning toburst out and describes an excessive flow; menorrhagia is,thus, profuse menstruation)• menostasis (-stasis means stoppage, so this word has thesame meaning as amenorrhea)• oligomenorrhea (oligo- means scant or little, so oligomenor-rhea is scant menstrual flow or scant menstruation).


Dissecting dysmenorrhea and more

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• Gynecomastia is abnormal enlargement or develop-ment of the male breast.• Hypospadias is the opening of the male urethra on theunderside of the penis.• Infertile means a diminished capacity to produce off-spring. An infertile man or woman isn’t necessarily sterile.• Introitus is the entrance into a canal such as the vagi-na.• Leukorrhea is a white or yellowish discharge from thevagina.• Libido is sexual desire.• Lithotomy position is a supine position with the hipsand knees fully flexed. It’s used to perform female inter-nal pelvic examinations. • Mastalgia is pain in the breast.• Menarche is the time when the first menstrual cyclebegins.• Metrorrhagia is abnormal uterine bleeding, especiallybetween menstrual periods.• Orgasm is the climax of sexual excitement.• Priapism is a persistent, abnormal erection of the pe-nis that isn’t accompanied by sexual desire.• Rectovaginal palpation is the examination of theposterior portion of the uterus and pelvic cavity by simul-taneously inserting a gloved finger into the rectum andvagina.• Speculum is an instrument used to enlarge the vaginalcanal opening during a female pelvic examination.• Sterile means that the patient is unable to reproducedue to an abnormality, such as the absence of spermato-genesis in a man or fallopian tube blockage in a woman.• Supernumerary nipples are more than one nipple lo-cated on a breast.

Diagnostic tests

Diagnostic tests associated with the reproductive systeminclude blood and fluid tests as well as radiologic andother imaging procedures.


Leukorrhea is a

white discharge—

that makes sense.

Leuk is Greek for

white and -rrhea

means flow.

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Blood and fluid testsHere are some common blood and fluid tests associatedwith the reproductive system:• A darkfield examination is a microscopic test of fluidtaken from a lesion in suspected primary syphilis. A spe-cial microscope makes the syphilis organism appearbright against a dark background (therefore, the termdarkfield).• A Papanicolaou (Pap) smear is widely used for earlydetection of cervical cancer and inflammatory tissuechanges. (See Pap smear.)• A prostate-specific antigen (PSA) blood test is usedto detect increases in PSA, a normally occurring sub-stance that can indicate prostate disease.• The prostatic acid phosphatase test measures thelevel of phosphatase enzymes, usually found in theprostate. Above-normal levels are suspicious for prostatecancer.• Semen analysis is an examination of seminal fluid toevaluate male fertility. The procedure includes measuringthe volume of seminal fluid, counting sperm, and per-forming microscopic examination.• A serum alpha-fetoprotein (AFP) study measuresthe glycoprotein AFP. An above-normal level may indi-cate testicular cancer. In a fetus, an above-normal levelmay indicate a neural tube defect.• In a urine culture, a common culture medium is usedto detect infectious microorganisms in urine.• A Venereal Disease Research Laboratory (VDRL)test confirms a diagnosis of syphilis.

Radiologic and other imaging proceduresHere are some common radiologic and other imagingprocedures associated with the reproductive system:• During colposcopy, the examiner studies the vulva,cervix, and vagina with a colposcope, an instrumentcontaining a magnifying lens and light.• Hysterosalpingography allows visualization of theuterine cavity, the fallopian tubes, and the peritubal area.(See Making sense of hysterosalpingography, page 234.)

233DIAGNOSTIC TESTS

Pap smear

What everyone com-monly refers to as a Pap

smear or Pap test is for-mally called a Papanico-

laou test.It was named after

George Papanicolaou(1883-1962), a Greek doc-tor who immigrated tothe United States anddeveloped the test.

The realworld

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• Laparoscopy allows visual inspection of organs in theperitoneal cavity by inserting a fiber-optic telescope (la-paroscope) through the abdominal wall.• A mammogram uses low-dose X-rays to detect breastmalignancies and evaluate masses.• A pelvic ultrasound passes sound waves through thepelvic area, creating electronic images of internal struc-tures. This test can help to diagnose pelvic disease or ex-amine a developing fetus.• Sentinel node biopsy uses radionuclide imaging toidentify the first lymph node to receive drainage from atumor. It’s used in breast tumors and melanoma.• Transrectal ultrasound of the prostate is a scan ofthe prostate performed by placing an ultrasound trans-ducer into the rectum and imaging through the rectalwall. It may also be used to guide a biopsy of theprostate.• Urethrogram is an X-ray of the prostate and urethra.

Disorders

Common disorders associated with the reproductive sys-tem are usually gender specific. Sexually transmitted dis-eases (STDs), however, can affect either gender.


The Greek word hystero means uterus. Salpingo is the Greek term for fallopian tube, and -graphy

is the term for a recording. So, hysterosalpingography means examination of the uterus and fal-lopian tubes.

Sometimes the Greeks got it wrong

Hysteros, the Greek word for the uterus or womb, also provided the root for another Greek word:hysteria. It seems the ancient Greeks had the notion that only women became extremely emo-tionally upset. They attributed this perceived difference from men to the presence of the uterus.


Making sense of hysterosalpingography

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Female reproductive disordersHere are some common disorders associated with the fe-male reproductive system:• Dermoid cysts are generally benign ovarian cysts con-sisting of displaced embryonic tissue.• Endometriosis refers to a condition in which endome-trial tissue appears outside the lining of the uterine cavity.• Oligo-ovulation is irregular ovulation.• Ovarian cysts are noncancerous sacs containing fluidor semisolid material.• Pelvic inflammatory disease (PID) is an infection ofthe oviducts and ovaries.• Premenstrual syndrome (PMS) is characterized byvarying symptoms appearing 7 to 10 days before mensesand usually subsiding with its onset. The effects of PMSrange from minimal discomfort to severe disruptivesymptoms that can include nervousness, irritability, de-pression, and multiple somatic complaints.• Rectovaginal fistula is an abnormal communication(passage) between the vagina and the rectum.• Salpingitis is inflammation of a fallopian tube.• Uterine leiomyomas, also called myomas, fibromy-omas, or fibroids, are the most common neoplasms (tu-mors) occurring among women. They’re usually found inthe uterus or cervix.• Vaginismus is an involuntary, spastic constriction ofthe lower vaginal muscles.• Vesicovaginal fistula is an abnormal communicationbetween the vagina and the bladder.

Male reproductive disordersHere are some common disorders associated with themale reproductive system:• Cryptorchidism is a condition in which one or bothtestes fail to descend into the scrotum and remain in theabdomen, in the inguinal canal, or at the external in-guinal ring.• Epididymitis is inflammation of the epididymis.• Peyronie disease is the buildup of fibrous tissue inthe corpus cavernosum that causes a curvature of the pe-nis and pain that worsens with erection.

235DISORDERS

PMS always

makes me feel

fat and

irritable.

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• Premature ejaculation refers to a man’s inability tocontrol the ejaculatory reflex during intercourse, result-ing in persistently early ejaculation.• Prostatitis refers to a chronic inflammation of theprostate gland, usually from infection.

ImpotenceImpotence is also known as erectile dysfunction. Aman with this problem can’t attain or maintain sufficientpenile erection to complete intercourse. There are twotypes of impotence:• primary impotence, in which the patient has neverbeen able to achieve a sufficient erection to complete in-tercourse• secondary impotence, in which the patient has suc-ceeded in completing intercourse in the past.

Testicular torsionTesticular torsion is abnormal twisting of the spermaticcord that’s caused by rotation of the testis. Two types oftesticular torsion are:• extravaginal torsion, caused by loose attachment ofthe tunica to the scrotal lining which, in turn, causesspermatic cord rotation above the testis.• intravaginal torsion, resulting from an abnormal tu-nica or from narrowing of the muscular support. Normal-ly, the tunica vaginalis envelops the testis and attaches tothe epididymis and spermatic cord; in intravaginal tor-sion, testicular twisting may result from an anomaly ofthe tunica in which the testis is abnormally positioned orfrom narrowing of the muscular support.

Other reproductive disordersHere are some other common reproductive disorders:• Adenomyosis of the uterus is a condition in whichendometrial tissue invades the muscular layer of theuterus.• Benign prostatic hyperplasia refers to an enlarge-ment of the prostate gland.• In hematocele, blood collects in a body cavity, such asthe scrotum, testis, or pelvis.• Hydrocele is a collection of clear fluid in a testis.


Testicular torsionis abnormal twisting

of the spermatic cord

that’s caused by

rotation of the

testes.

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• Hyperplasia of the endometrium is the overdevelop-ment of the uterine lining.• Mastitis is an inflammation of the mammary glandsthat commonly occurs with breast-feeding.• Oligospermia is a condition in which the amount ofsperm in semen is low.• Phimosis is a constriction of the foreskin over the pe-nis that makes it unable to be drawn back over the glans.• Precocious puberty is the early onset of pubertalchanges, such as breast development and menstruationbefore age 9 (in females). Males with the disorder beginto sexually mature before age 10.• Prolapse of the uterus is the protrusion of the uterusthought the vaginal opening.• Pruritus vulvae is intense itching of the vulva.• Salpingocele is a hernial protrusion of the fallopiantube. (See Salpingocele story.)• Spermatocele is a cyst containing sperm cells that oc-curs near the epididymis.• A varicocele is an abnormal condition characterizedby dilation of the veins of the spermatic cord.

Sexually transmitted diseasesHere are the names of some common STDs and condi-tions that accompany them:• Chancroid, also called soft chancre, is a venereal dis-order marked by painful genital ulcers and inguinallymph node inflammation.• Chlamydia is the most common STD in the UnitedStates. This group of infections—which includes urethri-tis (inflammation of the urethra) in men and urethritisand cervicitis (cervical inflammation) in women—islinked to the Chlamydia trachomatis organism.• Genital herpes, also known as herpes simplexvirus, herpes type 2, or venereal herpes, is an acute,inflammatory infection that causes fluid-filled vesicles onthe genitalia. The vesicles rupture and develop into shal-low, painful ulcers.• Genital warts, also called condylomata acuminata,consist of painless papillomas (noncancerous skin tu-mors) with fibrous tissue overgrowth that commonlyhave a cauliflower-like appearance.

237DISORDERS

It seems a bit

ironic that STDs were

once called venerealafter Venus, the

goddess of love.

Salpingocelestory

Salpingocele is a herni-ation of the fallopiantube. The Greek wordsalpinex, for trumpet (a tubular instrument),gives us salpingo-,

which refers to the fal-lopian tubes. The -cele

means cavity and, thus,refers to a hernia.


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• Gonorrhea is a common disease caused by the Neisse-ria gonorrhoeae organism. This STD typically affects theurethra and cervix.• Syphilis is a chronic, infectious STD that begins in themucous membranes and quickly moves through the bodyby spreading to nearby lymph nodes and the blood-stream. The untreated disease process has four stages:

Primary syphilis occurs within 3 weeks of originalcontact. Patients may develop lymph node tendernessand chancres (small sores) on the body.

Secondary syphilis occurs from a few days to 8weeks after the appearance of sores. Patients develop arash, white lesions, and flulike symptoms.

Latent syphilis is characterized by an absence ofsymptoms.

Late syphilis, also called tertiary syphilis, in-volves other organs, such as those in the cardiovascularand central nervous systems.• Trichomoniasis is a protozoal infection of the lowerurinary tract and reproductive system.

Treatments and procedures

Here are terms related to surgeries and other treatmentsof the male and female reproductive systems:• Artificial insemination is the placement of seminalfluid into the patient’s vaginal canal or cervix. The proce-dure is coordinated with ovulation.• A cervicectomy is removal of the cervix.• Circumcision is the removal of all or part of the pre-puce (foreskin) of the glans penis.• In dilatation and curettage (D&C), a doctor dila-tates (expands) the cervix to access the endocervix anduterus. A curette (an instrument with sharp edges) isused to scrape away endometrial tissue. (See Just say“D&C.”)• In dilatation and evacuation, suction is used to re-move the uterine contents. This procedure is typicallyused to perform elective abortions.


Just say “D&C”

In the “real world,” di-

latation of the uterinecervix and curettage ofthe endometrium isknown as a “D and C.” Adilatation and evacua-

tion, in which suction isused to remove the uter-ine contents, is referredto as a “D and E.”

The realworld

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• With in vitro fertilization, an ovum is removed fromthe body and fertilized with sperm in a laboratory culturemedium. The resulting embryo is then transferred intothe woman’s uterus.• Kegel exercises are performed by contracting and re-laxing the perineal muscles in order to strengthen thepelvic floor muscles. Kegel exercises are helpful in treat-ing female urinary incontinence.• In a laparoscopy, surgical instruments are insertedthrough a laparoscope to remove small lesions or per-form other diagnostic and therapeutic procedures.• A laparotomy is a surgical incision through the ab-domen made to provide access to the peritoneal cavity.• Oophorectomy is excision of one or both ovaries. Bi-lateral oophorectomy results in surgically inducedmenopause in women who are still in the reproductivephase of life.• An orchiectomy is removal of one of the testes.• Orchiopexy is the fixation of an undescended testis inthe scrotum.• Penile prosthesis is an implanted device used to pro-vide penile erection.• Tubal ligation is the interruption of both fallopiantubes to prevent conception.• Vasectomy is excision of the vas deferens. When donebilaterally, this results in sterility.• Vasovasotomy is the restoration of the vas deferensafter a vasectomy in order to regain fertility.

HysterectomyHysterectomy is removal of the uterus. There are fourtypes:• Total hysterectomy, also called a panhysterectomy,is removal of all female reproductive organs, includingthe uterus, cervix, fallopian tubes, and ovaries. It’s calleda panhysterectomy because a rectangular “pan” isused during surgery to collect all the excised or-gans.• Subtotal hysterectomy is removal of only partof the uterus. The cervix is left intact.• Radical hysterectomy is removal of all of the re-productive organs and supporting structures.• Vaginal hysterectomy is excision of the uterusthrough the vagina.

239TREATMENTS AND PROCEDURES

Remember, the

word hystero-

means uterus and

-ectomy means

surgical removal.

Therefore, a

hysterectomy isremoval of the

uterus.

Memoryjogger

Both “la-paroscopy”

and “laparotomy” aresurgical procedures,but to help distin-guish their meaningsremember that la-paroscopy involvesusing a “scope” (la-paroscope) and la-parotomy involves asurgical incisionthrough the “tummy.”

845510.qxd 8/19/08 5:55 PM Page 239


Vocabulary builders

Across

1. Erectile dysfunction5. Lactogenic hormone8. Abbreviation for a venereal dis-ease test10. Visible female genitals15. Sperm formation

17. Hormone produced aftermenopause18. Female sex hormone20. Two egg-shaped glands withinthe scrotum21. Male sex hormones

Down

2. A duct system in the testes3. An instrument used to enlargethe vaginal canal opening during afemale pelvic examination4. Lining of the uterus6. Main body of the uterus7. Upper uterus9. The abnormal dilation of theveins of the spermatic cord

11. Mammary glands12. Tissue covering the vaginalopening13. Male sex hormone14. Two almond-shaped female or-gans16. Area between the anus and thevulva 19. Female sex cell

At a crossroadsCompleting this crossword puzzle will help you produce thecorrect terms for the reproductive system. Good luck!


1 2

3

4 5 6

7 8 9

10

11 12

13 14

15 16

17

18 19

20

21

845510.qxd 8/19/08 5:55 PM Page 240


Match gameMatch each description of a reproductive disorder or condition to its name.

Clues

1. Testicular torsion ____

2. Endometriosis ____

3. Leiomyoma ____

4. Trichomoniasis ____

5. Papillomas ____

6. Gynecomastia ____

7. Phimosis ____

Choices

A. Constriction of the foreskin

B. Enlargement of the male breast

C. Fibroid tumor

D. Ectopic uterine tissue

E. Genital warts

F. Twisting of the spermatic cord

G. Protozoal infection


Finish lineFill in the blanks below with the appropriate word(s).

1. Each ______ _____ is enclosed by a spermatic cord.

2. ________ stimulates milk production.

3. Surgical removal of the uterus is called a ________.

4. A procedure to visualize pelvic organs is called a _______.

5. The process of uniting a sperm and an egg in a culture dish is known as _________fertilization.

6. The process of instilling seminal fluid into a patient’s vaginal canal is called ________insemination.

7. An ________ is surgical removal of one of the testes.

845510.qxd 8/19/08 5:55 PM Page 241


1I M P O T E N C

2E

P3S

4E

5P R O L A

6C T I N P

N O D E7F

8V D R L

9V R I C

U O A10P U D E N D U M

N M11B R

12H U Y L

D E R I Y S M U

U T E C M13T I

14O M

15S

16P E R M A T O G E N E S I S V

E I S C N S A

R U T E T17E S T R O N E

I M S L O I

N E18E S T R

19O G E N

E T V S

U20T E S T I C L E S U

M R M

O21A N D R O G E N S

E

1. F; 2. D; 3. C; 4. G; 5. E; 6. B; 7. A

Match game

1. Vas deferens; 2. Prolactin; 3. Hysterectomy; 4. Laparoscopy; 5. In vitro; 6. Artificial; 7. Orchiectomy

Finish line

At a crossroads

Answers

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Pregnancy-related structures andfunctions

Pregnancy results when a female’s egg and a male’ssperm unite. This chapter focuses on the terminology as-sociated with pregnancy. (See Pronouncing key mater-nal health terms, page 244.)

ConceptionPregnancy begins with conception, also called fertiliza-tion. Conception occurs when an ovum in the fallopiantube is penetrated by a spermatozoon (sperm cell). Thespermatozoon and the ovum unite to form a single newcell.

Only the strong surviveAlthough a single ejaculation deposits several hundredmillion spermatozoa, many are destroyed by acidic vagi-nal secretions. However, when spermatozoa enter the

11

Health assessmentMaternal health

Just the facts


♦ terminology related to pregnancy and fetal devel-opment

♦ terminology needed for physical examination of thepregnant woman and her fetus

♦ tests that help diagnose common pregnancy-related problems

♦ pregnancy-related disorders and their treatments.

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cervical canal they’re able to survive because cervicalmucus protects them. Spermatozoa are typically viable(able to fertilize the ovum) for up to 2 days after ejacula-tion, but they can survive in the reproductive tract for upto 4 days.

Movin’ right alongSpermatozoa travel through the femalereproductive tract by means of flagellarmovements (whiplike movements of thetail). After spermatozoa pass through thecervical mucus, however, the female re-productive system assists them on theirjourney with rhythmic uterine contrac-tions that help them penetrate the fallopi-an tubes.

244MATERNAL HEALTH

Below is a list of key terms related to maternal health along with the correct way to pronouncethem.


Pronouncing key maternal health terms

Abruptio placentae

Amenorrhea

Ballottement

Conception

Epididymis

Fertilization

Gestation

Lochia

Placenta

Zygote

UHB-RUHP-SHEE-OH PLAH-SEN-TAY

AH-MEN-OR-REE-UH

BAHL-OT-MAW

KON-CEP-SHUHN

EP-UH-DID-UH-MISS

FER-TIL-UH-ZAY-SHUHN

JES-TAY-SHUHN

LOH-KEE-AH

PLAH-SEN-TAH

ZIGH-GOTE

You’ll always

know your pal if

you’ve ever

navigated the

cervical canal.

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Break on through to the other sideBefore a spermatozoon can penetrate the ovum, it mustdisperse the ovum’s granulosa cells (estrogen-producingcells) and penetrate the zona pellucida, the thick, trans-parent layer surrounding the incompletely developedovum. Enzymes in the spermatozoon’s acrosome (headcap) permit this penetration.

Divide and fuseAfter penetration, the ovum completes its second meioticdivision and the zona pellucida prevents penetration byother spermatozoa. The spermatozoon’s head then fuseswith the ovum nucleus, creating a cell nucleus with 46chromosomes. (See How fertilization occurs, page 246.)

Plant me and watch me growThe fertilized ovum, or zygote, immediately forms arounded mass of cells and travels from the fallopian tubeto the uterus. In the uterus, it implants itself in the uter-ine lining and begins growing.

GestationGestation, or the period of pregnancy that begins withconception and ends with childbirth, typically lasts 38 to40 weeks. During this time, the zygote divides continu-ously, and a complex sequence of pre-embryonic, embry-onic, and fetal developments transforms the zygote into afull-term fetus.

Sizing it upBecause the uterus grows throughout pregnancy,uterine size serves as a rough estimate of gesta-tion. However, the expected delivery date is typi-cally calculated from the beginning of the pregnantwoman’s last menses using Nägele’s rule:

First day of the last menstrual period – 3 months +7 days = estimated date of birth.

245PREGNANCY-RELATED STRUCTURES AND FUNCTIONS

Because the

fertilization date is

rarely known, a

woman’s expected

delivery date is

typically calculated

using Nägele’s rule.

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246MATERNAL HEALTH

Fertilization begins when the spermatozoon is activated upon contact with the ovum. Here’s what happens.


How fertilization occurs

The spermatozoon, which has a covering called the acrosome,

approaches the ovum.

The acrosome develops small perforations through which it re-leases enzymes necessary for the sperm to penetrate the pro-tective layers of the ovum before fertilization.

The spermatozoon then penetrates the zona pellucida (the in-ner membrane of the ovum). This movement triggers theovum’s second meiotic division (following meiosis), making thezona pellucida impenetrable to other spermatozoa.

After the spermatozoon penetrates the ovum, its nucleus is re-leased into the ovum, its tail degenerates, and its head en-larges and fuses with the ovum’s nucleus. This fusion providesthe fertilized ovum, called a zygote, with 46 chromosomes.

Ovum

Acrosome

Spermatozoon

Released enzymes

Dispersed granulosa cells

Penetration ofzona pellucida

Spermatozoonnucleusreleased intothe ovum

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Fetal developmentDuring pregnancy, the fetus undergoes three major stagesof development:

pre-embryonic period (the first 3 weeks after fertil-ization)

embryonic period (weeks 2 to 8)

fetal period (end of week 8 through birth).

Pre-embryonic periodThe pre-embryonic period starts with ovum fertilizationand lasts about 3 weeks. As the zygote passes through thefallopian tube, it undergoes a series of mitotic divisions,or cleavage. (See Pre-embryonic development, page248.)

Embryonic periodDuring the embryonic period (beginning at the end ofthe second week through the eighth week of gestation),the developing zygote starts to take on a human shapeand is now called an embryo. The growing embryo floatswithin the amnion, a thin, clear sac filled with amnioticfluid. Early in this period, the chorion, or outer cells ofthe rounded cell mass, joins with the endometrium toform the placenta. This vital structure provides nutri-ents for and removes wastes from the embryo via thechorion and the embryo’s umbilical cord.

Layer upDuring the embryonic period, three germ layers develop.Each germ layer—the ectoderm, mesoderm, and endo-derm—eventually forms specific tissues in the embryo.(See Embryonic development, page 249.)

All systems go!Organ systems form during the embryonic period. Duringthis time, the embryo is particularly vulnerable to injuryfrom such factors as maternal drug use and certain ma-ternal infections.



How did I get

my start? Well, it

all began in the

pre-embryonic

period…

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248MATERNAL HEALTH

The pre-embryonic period lasts from conception until about the end of the third week of development.


Pre-embryonic development

Zygote formation…

As the fertilized ovum advances through the fallopian tube to-ward the uterus, it undergoes mitotic division, forming daughtercells, initially called blastomeres. Each blastomere containsthe same number of chromosomes as the parent cell. The firstcell division ends about 30 hours after fertilization; subsequentdivisions occur rapidly.

The zygote, as it’s now called, develops into a small mass ofcells called a morula, which reaches the uterus at about thethird day after fertilization. Fluid that amasses in the center ofthe morula forms a central cavity.

…into blastocyst

The structure is now called a blastocyst. The blastocyst con-sists of a thin trophoblast layer, which includes the blastocystcavity, and the inner cell mass. The trophoblast develops intofetal membranes and the placenta. The inner cell mass later

forms the embryo (late blastocyst).

Getting attached: Blastocyst and endometrium

During the next phase, the blastocyst stays within the zona pel-lucida, unattached to the uterus. The zona pellucida degener-ates and, by the end of the first week after fertilization, theblastocyst attaches to the endometrium. The part of the blasto-cyst adjacent to the inner cell mass is the first part to becomeattached.

The trophoblast, in contact with the endometrial lining, pro-liferates and invades the underlying endometrium by separat-ing and dissolving endometrial cells.

Letting it all sink in

During the next week, the invading blastocyst sinks below theendometrium’s surface. The penetration site seals, restoringthe continuity of the endometrial surface.

Fertilization

Ovum

Zygote Firstmitoticdivision

Two-cellstage

(blastomere)

Morula Earlyblastocyst

Lateblastocyst

Blastocystcavity

Partiallyimplantedblastocyst

Uterine wall

Uterine cavity

Fallopian tube

Ovary

845511.qxd 8/19/08 7:17 PM Page 248


Each of the three germ layers—ectoderm, mesoderm, and endoderm—forms specific tissues andorgans in the developing embryo.


Embryonic development

Ectoderm

The ectoderm, the outermostlayer, develops into the:• epidermis• nervous system• pituitary gland• tooth enamel• salivary glands• optic lens• lining of lower portion ofanal canal• hair.

Mesoderm

The mesoderm, the middlelayer, develops into:• connective and supportingtissue• the blood and vascular sys-tem• musculature• teeth (except enamel)• the mesothelial lining ofpericardial, pleural, and peri-toneal cavities• the kidneys and ureters.

Endoderm

The endoderm, the innermostlayer, becomes the epitheliallining of the:• pharynx and trachea• auditory canal• alimentary canal• liver• pancreas• bladder and urethra• prostate.

Chorionic villi

Embryonic disk

Ectoderm

Mesoderm

Endoderm

During the

embryonic period,

three germ layers

develop—the

ectoderm,mesoderm, and

endoderm.

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Fetal periodThe fetal period lasts from the end of the eighth week un-til birth. During this period, the embryo enlarges, growsheavier, and becomes known as a fetus. The fetus’s headis disproportionately large compared to its body at thistime. (This feature changes after birth as the neonategrows.) The fetus also lacks subcutaneous fat. (Fat startsto accumulate shortly after birth.)

Structural changes related to pregnancyPregnancy changes the usual development of the corpusluteum and results in the development of these struc-tures:• decidua• amniotic sac and fluid• yolk sac• placenta.

DeciduaThe decidua is the endometrial lining of the uterus thatundergoes hormone-induced changes during pregnancy.Decidual cells secrete these substances:• the hormone prolactin, which promotes lactation(breast-feeding)• a peptide hormone called relaxin, which induces re-laxation of the connective tissue of the symphysis pubisand pelvic ligaments and promotes cervical dilation• a potent hormonelike fatty acid, prostaglandin, whichmediates several physiologic func-tions. (See Development of the de-cidua and fetal membranes.)

Amniotic sac and fluidThe amniotic sac, enclosed withinthe chorion, gradually grows andsurrounds the embryo. As it en-larges, the amniotic sac expandsinto the chorionic cavity, eventuallyfilling the cavity and fusing with thechorion by the eighth week of ges-tation.

250MATERNAL HEALTH

The decidua is the

endometrial lining of

the uterus that

undergoes hormone-

induced changes

during pregnancy.

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Specialized tissues support, protect, and nurture the embryo and fetus throughout its development. Among these tissues are thedecidua and fetal membranes, which begin to develop shortly after conception.


Development of the decidua and fetal membranes

Decidua

During pregnancy, the endometrial lining is called the decidua.

It provides a nesting place for the developing ovum and hassome endocrine functions.

Based primarily on its position relative to the embryo, thedecidua may be known as the decidua basalis, which lies be-neath the chorionic vesicle; the decidua capsularis, whichstretches over the vesicle; or the decidua parietalis, whichlines the remainder of the endometrial cavity.

Fetal membranes

The chorion is a membrane that forms the outer wall of theblastocyst. Vascular projections, called chorionic villi, arise

from its periphery. As the chorionic vesicle enlarges, villi aris-ing from the superficial portion of the chorion, called the chori-

on laeve, atrophy, leaving this surface smooth. Villi arising fromthe deeper part of the chorion, called the chorion frondosum,

proliferate, projecting into the large blood vessels within thedecidua basalis through which the maternal blood flows.

Blood vessels that form within the growing villi becomeconnected with blood vessels that form in the chorion, bodystalk, and within the body of the embryo. Blood begins to flowthrough this developing network of vessels as soon as the em-bryo’s heart starts to beat.

Approximately 4 weeks

Decidua basalis

Chorionic vesicle

Amnion

Yolk sac

Deciduaparietalis

Decidua capsularis

Cervix

Vagina

Approximately 16 weeks

Chorion frondosum

Decidua basalis

Yolk sac

Amnion

Chorion laeve

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Fluid factsAmniotic fluid comes from maternal and fetal sources.The amount of fluid in the amniotic sac is usually bal-anced with the amount lost through the fetal GI tract. Thefluid is absorbed into the fetal circulation from the fetalGI tract; some of it’s transferred from the fetal circulationto the maternal circulation and excreted in maternalurine.

Amniotic fluid serves the fetus in two ways. Duringgestation, the fluid gives the fetus a buoyant, tempera-ture-controlled environment. Later, amniotic fluid servesas a fluid wedge that helps to open the cervix duringbirth.

Yolk sacThe yolk sac forms next to the endoderm. A portion ofthis sac incorporates into the developing embryo andforms the GI tract. Another portion of it develops intoprimitive germ cells, which travel to the developing go-nads and eventually form oocytes (the precursor of theovum) or spermatocytes (the precursor of the sperma-tozoon) after gender has been determined. Early in em-bryonic development, the yolk sac also forms blood cells.Eventually, this sac atrophies and disintegrates.

PlacentaThe placenta is a flattened, disk-shaped structure thatuses the umbilical cord as a conduit to provide nutrientsto and remove wastes from the fetus from the thirdmonth of pregnancy until birth. The placenta is formedfrom the chorion, its chorionic villi, and the adjacent de-cidua basalis. It plays a key role in producing such hor-mones as estrogen, progesterone, and human placentallactogen during pregnancy.

Talkin’ about two circulationsThe placenta is a highly vascular organ and contains twospecialized circulatory systems:• The uteroplacental circulation carries oxygenatedarterial blood from the maternal circulation to the inter-villous spaces (large spaces separating chorionic villi inthe placenta).

252MATERNAL HEALTH

Ah! This is the life!

This amniotic fluid is

keeping me warm and

buoyant. I may never

want to leave!

The placenta

plays a key role

in hormone

production

during

pregnancy.

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• The fetoplacental circulation transports oxygen-depleted blood from the fetus to the chorionic villi by theumbilical arteries and returns oxygenated blood to the fe-tus through the umbilical vein.

Labor and birthLabor is the process by which birth of the fetus isachieved. During this time, the cervix dilates and theuterus contracts to expel the fetus from the uterus.

Stages of laborLabor is typically divided into four stages. The first stage,when effacement (thinning and shortening of the cervix)and dilation occur, begins with the onset of true uterinecontractions and ends when the cervix is fully dilated.This stage may be further divided into three phases:• latent phase, which begins with the onset of regularcontractions; the cervix dilates from 0 to 3 cm and be-comes fully effaced• active phase, which is characterized by strong, regular,recurrent contractions, cervical dilation from 4 to 7 cm,and fetal descent through the pelvis• transition phase, which is characterized by maximallyintense uterine contractions, cervical dilation from 8 to10 cm, and complete cervical effacement.

The stage is setThe other stages of labor are:• second stage, which encompasses the actual birth; itbegins when the cervix is fully dilated and ends with thebirth of the neonate• third stage, also called the placental stage, which be-gins immediately after the birth of theneonate and ends when the placenta isdelivered• fourth stage, which begins after de-livery of the placenta; during this stage,homeostasis is reestablished.


The transitionphase is

characterized by

maximally intense

uterine contractions,

cervical dilation from

8 to 10 cm, and

complete cervical

effacement. Talk

about hard work!

Memoryjogger

To staysharp on the

phases of the firststage of labor, re-member E FLAT.

Effacement

Latentphase

Active phase

Transition phase

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Cardinal movements of laborWith labor, the fetus must pass through the birth canal.To do so, the fetus must change position through variousmovements because of the size of the fetal head in rela-tion to the irregularly shaped maternal pelvis. Specific,deliberate, and precise, the various movements allow thesmallest diameter of the fetal head to pass through thecorresponding diameter of the woman’s pelvis. Thesemovements include:• descent, the downward movement of the fetus toreach the posterior vaginal floor• flexion, the bending forward of the head so that thechin is pressed to the chest that occurs as a result of theresistance of the fetal head against the pelvic floor• internal rotation, the movement of the head to atransverse (right to left) position• extension, the movement of the head as it passesthrough the pelvis, with the occiput (back part of thehead) emerging from the vagina and the back of the neckunder the symphysis pubis• external rotation (also called restitution), themovement of the head to face one of the mother’s innerthighs• expulsion, the birth of the remainder of the fetus’sbody.

Postpartum periodThe time frame after the birth of the neonate is called thepostpartum period. During this period, the mother’s re-productive tract begins to return to its former conditionthrough a process called involution. The uterus shrinksquickly during the first 2 weeks after childbirth. As theuterus contracts, the woman may experience pain, com-monly referred to as afterpains.

Discharge after being dischargedPostpartum vaginal discharge, called lochia, persists forseveral weeks. The color and consistency of the lochiachanges.• Lochia rubra is a bloody discharge that appears 1 to 4days after childbirth.

254MATERNAL HEALTH

The cardinal

movements of labor

allow the smallest

diameter of the fetal

head to pass through

the corresponding

diameter of the

woman’s pelvis.

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• Lochia serosa is a pinkish brown serous dischargethat appears 5 to 7 days after childbirth.• Lochia alba is a grayish white or colorless dischargethat appears 1 to 3 weeks after childbirth.

Mama’s milkA postpartum woman’s breasts undergo changes inpreparation for breast-feeding. If the woman chooses tobreast-feed, the first milk produced is called colostrum.It’s a thick, sticky, golden yellow, easy-to-digest fluid thatcontains protein, sugar, fat, water, minerals, vitamins, andmaternal antibodies. Colostrum is replaced by maturebreast milk by about the second to fourth postpartumday.


Here are terms associated with physical examination ofthe maternal patient:• Ballottement is passive fetal movement that occurs inresponse to pushing against the lower portion of theuterus. (See Ball toss.)• Bloody show refers to the vaginal discharge that oc-curs as the cervix thins and begins to dilate, allowing pas-sage of the mucus plug that seals the cervical canal dur-ing pregnancy.• Braxton Hicks contractions are episodes of light,painless, irregular tightening of the uterus during preg-nancy. They may occur during the first trimester and in-crease in duration and intensity by the third trimester.• Chadwick’s sign is a bluish coloration of the vulva andvagina that may occur after the sixth week of pregnancyas a result of local venous congestion.• Engorgement is the feeling of tightness, fullness, andtenderness in the postpartum woman’s breasts most like-ly resulting from venous and lymphatic stasis and accu-mulation of milk in the breast alveoli.• Goodell’s sign, softening of the cervix, is an indicationof probable pregnancy.• Gravida refers to a pregnant female. A woman iscalled gravida 1 during the first pregnancy, gravida 2 inthe second pregnancy, and so on.


Ball toss

Ballottement is the pas-sive fetal movement thatoccurs in response topushing against the low-er portion of the uterus.It’s a combination of theFrench word ballotter,

meaning to toss about,and the Italian word bal-

lotta, meaning ball.


845511.qxd 8/19/08 7:17 PM Page 255

• Hegar’s sign, softening of the lower portion of theuterus, occurs around the seventh week of pregnancy. It’sconsidered a sign of possible pregnancy.• Lightening is a subjective sensation reported by somewomen as the fetus descends into the pelvic inlet andchanges the shape and position of the uterus near term.• Linea nigra is a line of dark pigment that appears on apregnant woman’s abdomen.• Melasma refers to the darkened areas that may appearon the face, especially on the cheeks and across the nose;it’s also known as chloasma or the mask of pregnancy.• Obstetrics is the branch of surgical medicine involvingpregnancy and childbirth. It includes care of the motherand fetus throughout pregnancy, childbirth, and the post-partum period.• Para refers to a mother who has produced viable—butnot necessarily living—offspring. The numerals used af-ter the term (for example, para 1 or para 2) indicate thenumber of pregnancies that have produced viable off-spring.• Primigravida refers to a woman who’s pregnant forthe first time (also called gravida 1).• Primipara refers to a woman who has had one preg-nancy that resulted in a viable offspring or a womanwho’s pregnant for the first time (also called para 1).• Quickening refers to the first noticeable fetal move-ment in utero. It usually occurs at 16 to 20 weeks’ gesta-tion.• Ripening refers to the process in which the cervixsoftens to prepare for dilation and effacement.• Striae gravidarum, also called stretch marks, arered streaks that appear on a pregnant woman’s abdomen.• True labor is characterized by the uterine con-tractions that lead to cervical effacement and dila-tion, bloody show, and rupture of the membranes.

The fetal pictureHere are some terms associated with the physicalexamination involving the fetus:• Attitude is the degree of flexion and the rela-tionship of the fetal body parts to one another.• Breech presentation indicates that the fetus isin a head-up position with the buttocks (frankbreech), feet (incomplete or footling breech), or

256MATERNAL HEALTH

Melasma, also

known as chloasma,refers to the

darkened areas that

may appear on a

pregnant woman’s

face, especially on the

cheeks and across

the nose.

Striae gravidarum,also called stretch

marks, are red

streaks that appear

on a pregnant

woman’s abdomen.

845511.qxd 8/19/08 7:17 PM Page 256

buttocks and feet (complete breech) as the presentingparts.• Cephalic presentation indicates that the fetal head isthe first part to contact the cervix and be expelled fromthe uterus during birth.• Engagement occurs when the presenting part of thefetus passes into the pelvis to the point where the pre-senting part is at the level of the ischial spines. (See Fetalengagement and station.)• Lie refers to the relationship of the fetal spine to thematernal spine.• Position is the relationship of the presenting part ofthe fetus to a specific quadrant of the mother’s pelvis. It’sdesignated using three letters: The first letter denoteswhether the presenting part is facing the woman’s rightor left side (R or L). The second letter denotes the pre-senting part as occiput (O); mentum, or chin (M); sacrum


The extent of the fetalpresenting part intothe pelvis is referredto as fetal engage-

ment. Station refersto where the fetalpresenting part lies inrelation to the mater-nal ischial spines.Station grades rangefrom –3 (3 cm abovethe maternal ischialspines) to +4 (4 cmbelow the maternalischial spines, caus-ing the perineum tobulge). A zero stationindicates that the pre-senting part lies levelwith the ischial spines.


Fetal engagement and station

�3�2�1

0�1�2�3�4

Ischialspines

845511.qxd 8/19/08 7:17 PM Page 257

(Sa), or shoulder (A). The third letter denotes whetherthe presenting part points to the anterior (A), posterior(P), or transverse section of the mother’s pelvis (T).• Presentation is the portion of the fetus that first en-ters the birth canal.• Station is the relationship of the presenting part of thefetus to the mother’s ischial spines.

Diagnostic tests

Diagnostic tests associated with maternal health includeblood and fluid tests as well as imaging and other tests.

Blood and fluid testsHere are some common blood and fluid tests associatedwith maternal and fetal health:• Amniocentesis involves the withdrawal of a sample ofamniotic fluid by transabdominal puncture and needle as-piration. (See Quite a bowlful.)• Chorionic villus sampling is a biopsy in which aminute amount of the chorionic villi (fingerlike projec-tions of the chorion that attach to maternal endometrialtissues) is removed.• Indirect Coombs’ test is a blood test that screens ma-ternal blood for red blood cell antibodies.• Percutaneous umbilical blood sampling is an inva-sive procedure that involves insertion of a spinal needle

258MATERNAL HEALTH

The term amniocentesis derives from two Greek words: amnion

and kentsis. Amnion means bowl and kentsis means the act ofpricking. The “bowl” refers to the membrane that envelops thefetus. Put it all together and amniocentesis means the withdraw-al of a sample of amniotic fluid from the amniotic sac by trans-abdominal puncture and needle aspiration.


Quite a bowlful

845511.qxd 8/19/08 7:17 PM Page 258

into the umbilical cord to obtain a fetal blood sample orto transfuse the fetus in utero.• Serum alpha-fetoprotein (AFP) measures the glyco-protein AFP. An above-normal level in an adult may indi-cate testicular cancer. In a fetus, an above-normal levelmay indicate a neural tube defect.• A triple screen is a blood test performed between 15and 20 weeks’ gestation to determine whether a fetus isat increased risk for Down syndrome, a neural tube de-fect, or other chromosomal abnormalities.• A quadruple screen includes the triple screen bloodtest as well as an inhibin A test to more accurately pre-dict the likelihood of Down syndrome. This test, howev-er, isn’t available in all facilities.

Imaging and other diagnostic testsHere are some common imaging and other diagnostictests associated with maternal and fetal health:• Amniography is an X-ray of a pregnant woman’suterus. A contrast medium is injected into the amnioticsac to visualize its contents.• External electronic monitoring is an indirect, nonin-vasive procedure using two devices that are placed onthe pregnant abdomen—an ultrasound transducer thatdetects the baby’s heart rate and a tocotransducer thatrecords the pressure of uterine contractions. Togetherthey help to evaluate fetal well-being and uterine contrac-tions during labor.• Internal electronic monitoring, also called directmonitoring, is an invasive procedure that uses a spiralelectrode attached to the presenting fetal part to detectfetal heartbeat and convert it to a fetal electrocardiogramwaveform.• The nonstress test is a noninvasive test used to detectfetal heart accelerations in response to fetal movement.• The oxytocin challenge test evaluates the fetus’s abil-ity to withstand an oxytocin-induced contraction. Thetest requires nipple stimulation or I.V. administration ofoxytocin in increasing doses until three high-quality uter-ine contractions occur within a 10-minute period.• A pelvic ultrasound passes sound waves through thepelvic area, creating electronic images of internal struc-tures. This test is used to examine a developing fetus.

259DIAGNOSTIC TESTS

Screens aren’t just

for football, ya know.

A triple screen is a

blood test that

determines whether a

fetus is at increased

risk for Down

syndrome, a neural

tube defect, or other

chromosomal

abnormalities.

845511.qxd 8/19/08 7:17 PM Page 259

• The vibroacoustic stimulation test is a noninvasivetest using 1 to 5 seconds of vibration and sound to inducefetal reactivity during a nonstress test. Vibration is pro-duced by an artificial larynx or fetal acoustic stimulatorthat’s placed above the head of the fetus.

Disorders associated with pregnancy,labor, and birth

• Abruptio placentae is the premature separation of anormally positioned placenta in a pregnancy of at least 20weeks’ gestation. This separation may occur before orduring labor but always occurs before delivery. The clas-sic symptom is painful “rupturing” accompanied bybleeding.• Battledore placenta occurs when the umbilical cordattaches to the placenta marginally rather than centrally.• Cephalopelvic disproportion is a disproportion be-tween the size of the fetal head and the maternal pelvicdiameters, usually due to a narrowing or contraction ofthe birth canal, resulting in a failure to progress in labor.• Dystocia involves the failure or inability to progressthrough the stages of labor. (See How do I say dystocia?)• Eclampsia refers to the development of seizures in awoman with gestational hypertension.• Ectopic pregnancy is the implantation of a fertilizedovum outside the uterine cavity, usually in a fallopiantube.

260MATERNAL HEALTH

I’m feeling those

good vibrations! The

vibroacousticstimulation test is a

noninvasive test that

uses vibration and

sound to induce fetal

reactivity during a

nonstress test.

The term describing the failure or inability to progress throughthe stages of labor—dystocia—is pronounced DIS-TOH-SHUH.The three parts of the word are all derived from Greek terms.Dys means bad; toc (from the word tokos) means childbirth; andia means a state or condition.


How do I say dystocia?

845511.qxd 8/19/08 7:17 PM Page 260

• Gestational diabetes refers to diabetes that emergesduring pregnancy and may lead to the birth of a large fe-tus, possibly weighing more than 10 lb (4.5 kg).• Gestational hypertension is hypertension that usual-ly develops after the 20th week of pregnancy and isn’t ac-companied by protein in the urine.• Hydatidiform mole is an uncommon chorionic tumorof the placenta. Women with this type of tumor have agood chance of developing cancer later in life. It’s alsocalled gestational trophoblastic disease or molarpregnancy.• Hydramnios refers to an excess amount of amnioticfluid.• Hydrorrhea gravidarum is the discharge of thin, wa-tery fluid from the uterus during pregnancy.• Hyperemesis gravidarum is severe and unremittingnausea and vomiting after the first 12 weeks of pregnan-cy.• Isoimmunization, also called Rh incompatibility,refers to a condition in which the pregnant woman is Rh-negative but the fetus is Rh-positive. If this condition isleft untreated, the neonate can develop hemolytic dis-ease.• Oligohydramnios is a condition in which a less-than-normal amount of amniotic fluid is present in the amnionduring pregnancy. (See Taking apart oligohydramnios.)• Placenta previa is a placenta that develops in the low-er segment of the uterus. It’s characterized by painlessbleeding, which differentiates this disorder from abruptioplacentae.• Precipitous labor occurs when uterine contractionsare so strong that the woman gives birth with only a fewrapidly occurring contractions. It’s commonly defined aslabor lasting less than 3 hours.• Preeclampsia refers to the nonconvulsive form of hy-pertension, manifested by the development of hyperten-sion after the 20th week of gestation and accompanied byprotein in the urine. It may progress to eclampsia.• Premature labor, also called preterm labor, is theonset of rhythmic uterine contractions that produce cer-vical changes after fetal viability but before fetal maturity(usually between 20 and 37 weeks’ gestation).

261DISORDERS ASSOCIATED WITH PREGNANCY, LABOR, AND BIRTH

Hyperemesisgravidarum is severe

and unremitting

nausea and vomiting

after the first 12

weeks of pregnancy.

Taking apartoligohydramnios

Oligohydramnios is aless-than-normal amountof amniotic fluid. Theword oligo- means fewor scanty. Hydro- meanswater or fluid, and -am-

nios refers to the am-nion. Thus, oligohydram-

nios means little fluid inthe amnion.


845511.qxd 8/19/08 7:17 PM Page 261

• Premature rupture of membranes (PROM) is aspontaneous break or tear in the amniotic sac before theonset of regular contractions.• Spontaneous abortion is the premature expulsion ofan embryo or nonviable fetus from the uterus.• Umbilical cord prolapse occurs when a loop of theumbilical cord slips down in front of the fetal presentingpart. It may occur at any time after the membranes rup-ture, especially if the presenting part isn’t fitted firmlyinto the cervix.

Treatments and procedures

Here are terms related to treatments and procedures as-sociated with pregnancy, labor, and birth.• Abortion is the termination of a pregnancy. It can bespontaneous (from natural causes), elective (performedas a result of a choice to terminate the pregnancy), ortherapeutic (performed to preserve the woman’s life orwhen serious birth defects are expected). Controversialpartial birth abortions are those performed late in preg-nancy.• Amniotomy requires the use of an instrument such asan amniohook to mechanically rupture the membranes.• Artificial insemination is the placement of seminalfluid into the patient’s vaginal canal or cervix. The proce-dure is coordinated with ovulation.• Cervical suturing, also called cerclage, is the use ofa purse-string suture to reinforce the cervix.• Cesarean birth involves an incision made through theabdominal and uterine walls to deliver a neonate.• In dilatation and evacuation, suction is used to re-move the uterine contents. This procedure is typicallyused to perform elective abortions.• Episiotomy is an incision made in the vulva to preventtearing during birth of a neonate.• Gamete intrafallopian transfer is a reproductivetechnology that involves placing ova collected from theovaries transvaginally into a catheter filled with sperm.The contents of the catheter are injected into the end ofthe fallopian tube via a laparoscope. This technique al-lows fertilization and implantation to occur naturally.

262MATERNAL HEALTH

PROM is a

spontaneous

break or tear in

the amniotic sac

before the onset

of regular

contractions.

845511.qxd 8/19/08 7:17 PM Page 262

• With in vitro fertilization, an ovum is removed fromthe woman’s body and fertilized with sperm in a laborato-ry culture medium. The resulting embryo is then trans-ferred into the woman’s uterus.• Labor induction involves stimulating the onset ofuterine contractions by medical or surgical methods be-fore the woman begins labor spontaneously.• RhoGAM administration is the administration of Rho(D) immune globulin containing Rho (D) antibodies to awoman who is Rh-negative. This procedure keeps themother from producing active antibody responses andforming anti-Rho (D) to Rh-positive fetal blood cells.• Tocolytic therapy involves using medications to quietthe contracting uterus when preterm labor occurs.• Zygote intrafallopian tube transfer is a reproduc-tive technology that involves fertilization of the ovumoutside the mother’s body followed by reimplantation ofthe zygote into the fallopian tube via laparoscopy.

263TREATMENTS AND PROCEDURES

Feeling lucky? Try

your hand at winning

games about

maternal health on

the next page.

845511.qxd 8/19/08 7:17 PM Page 263

264MATERNAL HEALTH

Vocabulary builders

Across

4. Breast-feeding7. Postpartum vaginal discharge11. Period of pregnancy that be-gins with conception and endswith childbirth12. A pregnant female

13. The first noticeable fetal move-ment in utero14. Thinning and shortening of thecervix15. Rh incompatibility

Down

1. The termination of a pregnancy2. First milk produced after child-birth3. Endometrial lining of the uterus5. Precursor of the ovum6. Process by which birth of the fe-

tus is achieved8. An excessive amount of amniot-ic fluid9. Cells that move by means of fla-gellar movements10. Also called fertilization

At a crossroadsTest your maternal instincts by completing this crosswordpuzzle of maternal health terms.


1

2

3

4 5

6

7 8

9

10

11

12 13

14

15

845511.qxd 8/19/08 7:17 PM Page 264


Finish lineFill in the blanks with the appropriate terms.

1. __________________ contractions are episodes of light, painless, irregular uterinetightening during pregnancy.

2. The degree of flexion and the relationship of the fetal body parts to one another iscalled _______________.

3. ______________________ involves the withdrawal of a sample of amniotic fluid bytransabdominal puncture and needle aspiration.

4. The implantation of a fertilized ovum outside the uterine cavity, usually in a fallopiantube, is called an __________ pregnancy.

5. _____________________ involves using medications to quiet the contracting uteruswhen preterm labor occurs.


Match gameMatch each description of a disorder, condition, or treatment to its name.

Clues

1. Occurs when a loop of the umbilical cordslips down in front of the fetal presenting part___

2. An incision made in the vulva to preventtearing during birth of a neonate ____

3. The use of suction to remove the uterinecontents ___

4. Premature separation of a normally posi-tioned placenta in a pregnancy of at least 20weeks’ gestation ___

5. The use of an instrument to mechanicallyrupture the membranes ___

6. An uncommon chorionic tumor of the pla-centa ___

7. The use of a purse-string suture to reinforcethe cervix ___

Choices

A. Abruptio placentae

B. Hydatidiform mole

C. Umbilical cord prolapse

D. Cervical suturing

E. Dilatation and evacuation

F. Episiotomy

G. Amniotomy

845511.qxd 8/19/08 7:17 PM Page 265

266MATERNAL HEALTH

1. Braxton Hicks; 2. Attitude; 3. Amniocentesis; 4. Ectopic; 5. Tocolytic therapy

Finish line

1. C; 2. F, 3. E; 4. A; 5. G; 6. B; 7. D

Match game

At a crossroads

Answers

1A

B2C O

O R3D

4L A C T A T I

5O N E

O I O C6

L

S O C I7

L O C8H I A

T9S N Y D Y B

R P T U10C D O

U E11G E S T A T I O N R R

M R N A

M C M12G R A V I D A

13Q U I C K E N I N G

T P I

O14E F F A C E M E N T O

Z I S15

I S O I M M U N I Z A T I O N

A N

845511.qxd 8/19/08 7:17 PM Page 266

Neurologic structure and function

The neurologic system, also called the nervous system,coordinates all body functions, enabling a person toadapt to changes in internal and external environments.It has two main types of cells (neurons and neuroglia)and two main divisions (the central nervous system[CNS] and peripheral nervous system). (See Pro-nouncing key neurologic system terms, page 268.)

Cells of the nervous systemThe nervous system is packed with intertwined cells.

Neurons—the naked truthNeurons, the primary functional unit of the nervous sys-tem, respond to stimuli and transmit responses by meansof electromechanical messages.

The main parts of a neuron are the cell body (whichcontains the nucleus [plural: nuclei]) and the cyto-plasm. This is the metabolic center of the neuron. One

12

Health assessmentNeurologic system

Just the facts


♦ terminology related to the structure and function ofthe neurologic system


♦ tests that help diagnose common neurologic disor-ders

♦ neurologic system disorders and their treatments.

845512.qxd 8/19/08 6:16 PM Page 267

axon and several dendrites project from each cell body.(See Parts of a neuron.) In a typical neuron, one axonand many dendrites extend from the cell body.

Shipping and receivingAxons conduct nerve impulses away from the cell body.Dendrites conduct impulses toward the cell body.

The main function of the axon is to send or transmitsignals to other cells. The highly specialized neuron cellscan’t replace themselves but will attempt to repair them-selves if damage is limited to the axon.

Axons can vary in length from quite short to verylong—up to 31⁄4� (1 m). A typical axon has terminalbranches and is wrapped in a white, fatty, segmentedcovering called a myelin sheath. The myelin sheath isproduced by Schwann cells, made up of phagocyticcells (cells capable of engulfing and digesting micro-organisms and cellular debris) separated by gaps callednodes of Ranvier. (See Schwann and Ranvier, page270.)

268NEUROLOGIC SYSTEM

Below is a list of key terms related to the neurologic systemalong with the correct ways to pronounce them.


Pronouncing key neurologicsystem terms

Choroid plexus

Echoencephalography

Guillain-Barré syndrome

Gyri

Neuroglia

Sulci

Trigeminal neuralgia

Ventriculoperitoneal shunt

KOR-OYD PLEK-SEHS

EK-OH-EN-SEF-UH-LAWG-RUH-FEE

GEE-LAYN BAHR-RAY SIN-DROHM

JEYE-REYE

NEW-ROG-GLEE-UH

SUHL-KEYE

TREYE-JEM-UH-NUHL NEW-RAL-JEE-UH

VEN-TRIK-YOU-LOH-PER-UH-TOH-NEE-UHL SHUHNT

845512.qxd 8/19/08 6:16 PM Page 268

Dendrites are short, thick, diffusely branched exten-sions that receive impulses arriving at the neuron fromother cells.

Being impulsiveThe purpose of a neuron is to initiate, receive, and pro-cess messages through electrochemical conduction ofimpulses, also known as neurotransmission. Neuronactivity can be provoked by mechanical stimuli, such as

269NEUROLOGIC STRUCTURE AND FUNCTION

A typical neuron, such as the one shown here, has one axon andmany dendrites. A myelin sheath encloses the axon.


Parts of a neuron

Cell body

Nucleus of cell body

Dendrite

Axon

Myelin sheath(MEYE-UH-LUHN)

Neurons

respond to stimuli

and transmit

responses by

means of electro-

mechanical

messages.

845512.qxd 8/19/08 6:16 PM Page 269

touch and pressure; by thermal stimuli, such as heat andcold; and by chemical stimuli, such as external chemicalsand chemicals released by the body, such as histamine.

Neuro-glueThe supportive structures of the nervous system, neu-roglia, are also called glial cells. Glial is derived fromthe Greek word for glue; these cells hold the neurons to-gether and form roughly 40% of the brain’s bulk. In addi-tion, glial cells nourish and protect the neurons. Fourtypes of neuroglia exist:

Astroglia, or astrocytes, exist throughout the ner-vous system. They supply nutrients to neurons and helpthem maintain their electrical potential. Astrocytes alsoform part of the blood-brain barrier that separates CNStissue from the bloodstream and guards against invasionby disease-causing organisms and other harmful sub-stances.

Ependymal cells line the ventricles, four smallcavities in the brain, as well as the choroid plexuses,vascular structures that form a network in the pia materof the brain and project into the third, lateral, and fourthventricles. These cells help produce cerebrospinal fluid(CSF).

Microglia are phagocytic cells that ingest and digestmicroorganisms and waste products from injured neu-rons, giving them an important role in host defense.

Oligodendroglia support and electrically insulateCNS axons by forming protective myelin sheaths.


Bonjour.Guten

morgen.

Schwann cells are named after Theodor Schwann, a 19th-century German anatomist and physiologist who studied muscu-lar activity. In 1837, he published an important book on the work-ings of the cell in plants and animals.

Louis Antoine Ranvier, a French pathologist, first describedthe nodes of Ranvier in 1878.


Schwann and Ranvier

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BrainThe CNS includes the spinal cord and the brain. Thebrain consists of the cerebrum, cerebellum, brain stem,and primitive structures that lie below the cerebrum—thediencephalon, limbic system, and reticular activatingsystem. (See Major structures in the brain, page 272.)

You’re so cerebralThe cerebrum has right and left hemispheres. The cor-pus callosum—a mass of nerve fibers—bridges thehemispheres, allowing communication between corre-sponding centers in each. The rolling surface of the cere-brum is made up of gyri (convolutions) and sulci(creases or fissures). The thin surface layer, the cerebralcortex, consists of gray matter (unmyelinated nervefibers). Within the cerebrum lie white matter (myelinat-ed nerve fibers) and islands of internal gray matter.

Name that lobeEach cerebral hemisphere is divided into four lobes,based on anatomic landmarks and functional differences.The lobes are named for the cranial bones that lie overthem—frontal, temporal, parietal, and occipital:• The frontal lobe influences personality, judgment, ab-stract reasoning, social behavior, language expression,and movement.• The temporal lobe controls hearing, language com-prehension, and storage and recall of memories (al-though memories are stored throughout the entire brain).• The parietal lobe interprets and integrates sensations,including pain, temperature, and touch. Italso interprets size, shape, distance, and tex-ture. The parietal lobe of the nondominanthemisphere is especially important for aware-ness of one’s own body shape.• The occipital lobe functions primarily tointerpret visual stimuli.

Celebrating the cerebellumThe cerebellum, the second largest brain re-gion, lies posterior and inferior to the cere-brum. Like the cerebrum, it has two hemi-spheres, an outer cortex of gray matter and


Let’s talk

about

communication.

Okay. The

corpus callosumbridges my right

and left

hemispheres,

allowing

communication

between them.

845512.qxd 8/19/08 6:16 PM Page 271


These illustrations show the two largest structures of the brain—the cerebrum and cerebellum.Also note the locations of the four cerebral lobes, the sensory cortex, and the motor cortex.The bottom illustration shows a cross section of the brain, from its outermost portion (cerebrum)to its innermost (diencephalon).


Major structures in the brain

My lobes are

named for the

cranial bones that

lie over them—

frontal, temporal,

parietal, and

occipital.Sensory cortex

Motor cortex

Frontal lobe

Parietal lobe

Occipital lobe

Temporal lobe

Cerebellum

Diencephalon(DEYE-EN-SEF-UH-LUHN)

Cerebellum

Cerebrum

Brain stem

845512.qxd 8/19/08 6:16 PM Page 272

an inner core of white matter. The cerebellum functionsto maintain muscle tone, coordinate muscle movement,and control balance.

Brain stemThe brain stem lies immediately inferior to the cere-brum, just anterior to the cerebellum. It’s continuouswith the cerebrum superiorly and with the spinal cord in-feriorly.

Composed of the midbrain, pons, and medulla oblon-gata, the brain stem relays messages between the parts ofthe nervous system. It has three main functions:

It produces the rigid autonomic behaviors necessaryfor survival, such as increasing heart rate and respiratoryrate and stimulating the adrenal medulla to produce epi-nephrine.

It provides pathways for nerve fibers between higherand lower neural centers.

It serves as the origin for 10 of the 12 pairs of cranialnerves.

The reticular activating system (RAS), a diffusenetwork of hyperexcitable neurons, fans out from thebrain stem through the cerebral cortex. After screeningall incoming sensory information, the RAS channels it toappropriate areas of the brain for interpretation. RAS ac-tivity also stimulates wakefulness or arousal of con-sciousness.

Where nerves volunteerThe midbrain connects dorsally with the cerebellum andextends from the pons to the hypothalamus. It containslarge voluntary motor nerve tracts running betweenthe brain and spinal cord.

The pons pathwayThe pons connects the cerebellum with the cerebrumand links the midbrain to the medulla oblongata. Ithouses two of the brain’s respiratory centers thatwork with those in the medulla to produce a normalbreathing rhythm. The pons also acts as a pathwaybetween brain centers and the spinal cord and servesas the exit point for cranial nerves V, VI, and VII.


It makes perfect

sense. The pons acts

as a pathway, and

pons is the Latin

term for bridge.

Memoryjogger

To distin-guish the lo-

cations of the “cere-brum” and the “cere-bellum,” look at the“BR” in “cereBRum”and think “BRow,”meaning that thecerebrum is the top(the outermost) partof the brain.

For “cerebellum,” lookat the “BEL” in “cere-BELlum” and think“BELow” because thecerebellum is belowand behind the cere-brum.

845512.qxd 8/19/08 6:16 PM Page 273

Inferior, not unimportantThe medulla oblongata, the most inferior portion of thebrain stem, is a small, cone-shaped structure. It joins thespinal cord at the level of the foramen magnum, anopening in the occipital portion of the skull. The medullaoblongata serves as an autonomic reflex center to main-tain homeostasis, regulating respiratory, vasomotor, andcardiac functions.

Primitive structuresThe diencephalon consists of the thalamus and hypo-thalamus, which lie beneath the surface of the cerebralhemispheres. The thalamus relays all sensory stimuli(except olfactory) as they ascend to the cerebral cortex.Its functions include primitive awareness of pain, screen-ing of incoming stimuli, and focusing of attention. Thehypothalamus controls or affects body temperature, ap-petite, water balance, pituitary secretions, emotions, andautonomic functions (including sleep and wake cycles).

Limbo with the limbic systemThe limbic system is a primitive brain area deep withinthe temporal lobe. In addition to initiating basic drives,such as hunger, aggression, and emotional and sexualarousal, the limbic system screens all sensory messagestraveling to the cerebral cortex. (See Limbic system andbrain stem.)

Spinal cordA cylindrical structure in the vertebral canal, the spinalcord extends from the foramen magnum at the base ofthe skull to the upper lumbar region of the vertebral col-umn. The spinal nerves arise from the cord. At the cord’sinferior end, nerve roots cluster in the cauda equina.

Horn of sensation, horn of activityWithin the spinal cord, the H-shaped mass of gray matteris divided into horns, which consist mainly of neuron cellbodies. Cell bodies in the posterior horn primarily relaysensations; those in the anterior horn play a part in vol-untary and involuntary (reflex) motor activity. White mat-ter surrounding the outer part of these horns consists of


Note to

hypothalamus:

Please adjust your

thermostat!

845512.qxd 8/19/08 6:16 PM Page 274

myelinated nerve fibers grouped functionally in verticalcolumns, or tracts.

Impulse conductorThe spinal cord conducts sensory nerve impulses to thebrain and conducts motor impulses from the brain. It alsocontrols such reflexes as the knee-jerk (patellar) reactionto a reflex hammer.

Pathways in the brainNerve impulses to the brain follow sensory pathways.Nerve impulses from the brain—those that control bodyfunction and movement—follow motor pathways.

Sensory pathwaysSensory impulses travel via the afferent, or ascending,neural pathways to the brain’s sensory cortex in the pari-


The major structures of the limbic system and brain stem, shown here, are associated with emo-tions and responses such as anger, fear, and sexual arousal.


Limbic system and brain stem

Corpus callosum(KOR-PUHSKAH-LOH-SUHM)

Thalamus(THAL-UH-MUHS)

Hypothalamus(HEYE-POH-THAL-UH-MUHS)

Midbrain

Pons

Medulla oblongata

Spinal cord

845512.qxd 8/19/08 6:16 PM Page 275

etal lobe, where they’re interpreted. These impulses usetwo major pathways.

Ouch!Pain and temperature sensations enter the spinal cordthrough the dorsal horn. After immediately crossing overto the opposite side of the cord, these stimuli then travelto the thalamus via the spinothalamic tract.

Touchy-feely with the gangliaTactile, pressure, and vibration sensations enter the spinalcord via relay stations called ganglia (knotlike masses ofnerve cell bodies on the dorsal roots of spinal nerves).These stimuli then travel up the spinal cord in the dorsalcolumn to the medulla, where they cross to the oppositeside and enter the thalamus. The thalamus relays all in-coming sensory impulses (except olfactory impulses) tothe sensory cortex for interpretation.

Motor pathwaysMotor impulses travel from the brain to the muscles viaefferent, or descending, pathways. Originating in themotor cortex of the frontal lobe, these impulses reach thelower motor neurons of the peripheral nervous systemvia upper motor neurons. Upper motor neurons origi-nate in the brain and form two major systems:

Just an impulse• The pyramidal system, also called the corticospinaltract, is responsible for fine motor movements of skele-tal muscle. Impulses in this system travel from the motorcortex, through the internal capsule, and to the medulla,where they cross to the opposite side and continue downthe spinal cord.• The extrapyramidal system, or extracorticospinaltract, controls gross motor movements. Impulses origi-nate in the premotor area of the frontal lobe and travel tothe pons, where they cross to the opposite side. Then theimpulses travel down the spinal cord to the anterior horn,where they’re relayed to the lower motor neurons. Theseneurons, in turn, carry the impulses to the muscles.


Ouch! I

shouldn’t have

touched that hot

pan! Better alert

the spinothalamic

tract.

845512.qxd 8/19/08 6:16 PM Page 276

It’s all automaticReflex responses occur automatically, without any braininvolvement, to protect the body. Spinal nerves, whichhave both sensory and motor portions, mediate deeptendon reflexes—involuntary contractions of a muscleafter brief stretching caused by tendon percussion—andsuperficial reflexes—withdrawal reflexes elicited bynoxious or tactile stimulation of the skin, cornea, or mu-cous membranes.

A simple reflex, such as the knee-jerk reflex, re-quires an afferent (sensory) neuron and an efferent (mo-tor) neuron. (See Patellar reflex arc.)


Patellar reflex arcSpinal nerves—which have sensory and motor portions—con-trol deep tendon and superficial reflexes. A simple reflex arc re-quires a sensory (or afferent) neuron and a motor (or efferent)neuron. The knee-jerk, or patellar, reflex illustrates the se-quence of events in a normal reflex arc.

First, a sensory receptor detects the mechanical stimulusproduced by the reflex hammer striking the patellar tendon.Then the sensory neuron carries the impulse along its axon by

way of the spinal nerve to the dorsal root, where it enters thespinal column.

Next, in the anterior horn of the spinal cord, shown below,the sensory neuron joins with a motor neuron, which carriesthe impulse along its axon by way of the spinal nerve to the muscle. The motor neuron transmits the impulse to musclefibers through stimulation of the motor end plate. This triggersthe muscle to contract and the leg to extend.

Patellar reflex arc

Anterior horn of cord

Dorsal root ganglion

Spinal nerve

Sensory neuron

Motor neuron

Motor end plate

Sensory receptor

845512.qxd 8/19/08 6:16 PM Page 277

Protective structures of the CNSThe brain and spinal cord are protected from shock andinfection by bones, the meninges, several additional cush-ioning layers, and CSF.

BonesThe skull, formed of cranial bones, completely surroundsthe brain. It opens at the foramen magnum, where thespinal cord exits.

The vertebral column protects the spinal cord. Its30 vertebrae are separated from one another by an inter-vertebral disk that allows flexibility.

MeningesThe meninges cover and protect the cerebral cortex andspinal column. They consist of three layers of connectivetissue: the dura mater, arachnoid membrane, and piamater. (See Protective membranes of the CNS.)

The dura mater truly mattersThe dura mater is a fibrous membrane that lines theskull and forms reflections, or folds, that descend intothe brain’s fissures and provide stability. The dural foldsinclude:• the falx cerebri, which lies in the longitudinal fissureand separates the cerebral hemispheres• the tentorium cerebelli, which separates the cere-brum from the cerebellum• the falx cerebelli, which separates the two lobesof the cerebellum.

The arachnoid villi, projections of the duramater into the superior sagittal and transverse sinus-es, serve as the exit points for CSF drainage into thevenous circulation.

Arachnoid phobia?A fragile, fibrous layer of moderate vascularity, thearachnoid membrane lies between the dura materand pia mater.


Guess what,

little one. Pia

mater is the Latin

term for gentle

mother. Dura

mater is Latin for

tough mother.

845512.qxd 8/19/08 6:16 PM Page 278

Thin and richThe extremely thin pia mater, the innermost layer, has arich blood supply. It adheres to the brain’s surface andextends into its fissures.

Cushioning layersThree layers of space further cushion the brain and spinalcord against injury. The epidural space (actually, a po-tential space) lies over the dura mater. The subduralspace is situated between the dura mater and arachnoidmembrane. This closed area—typically the site of hemor-rhage after head trauma—offers no escape route for ac-


Three membranes—the dura mater, arachnoid membrane, and pia mater—help protect the cen-tral nervous system (CNS). The arachnoid villi project from the arachnoid membrane into the su-perior sagittal and transverse sinuses. The subarachnoid space, filled with cerebrospinal fluid,separates the arachnoid membrane from the pia mater.


Protective membranes of the CNS

Arachnoid villi(UH-RAK-NOYD VILL-EE)

Superior sagittal sinus

Subarachnoid space(SUHB-UH-RAK-NOYD)

Skin

Periosteum

Skull

Dura mater

Arachnoid membrane

Pia mater

The epidural

space, subdural

space, and

subarachnoid

space protect me

against injury.

845512.qxd 8/19/08 6:16 PM Page 279

cumulated blood. The subarachnoid space, filled withCSF, separates the arachnoid membrane and pia mater.

Cerebrospinal fluidCSF is a colorless fluid that arises from blood plasma andhas a similar composition. It cushions the brain andspinal cord, nourishes cells, and transports metabolicwaste.

Fluid factoryCSF forms continuously in clusters of capillaries calledthe choroid plexuses, located in the roof of each ventri-cle. The choroid plexuses produce approximately 500 mlof CSF each day.

Open to flowFrom the lateral ventricles, CSF flows through the inter-ventricular foramen, commonly known as the fora-men of Monro, to the third ventricle of the brain. Fora-men is a term used to describe a natural opening or pas-sage. The foramen of Monro is named after the man whofirst described it: Alexander Monro II, a professor ofanatomy at the University of Edinburgh. (See Three menof Monro.)

From there, it reaches the subarachnoid space andthen passes under the base of the brain, upward over thebrain’s upper surfaces, and down around the spinal cord.Eventually, it reaches the arachnoid villi, where it’s reab-sorbed into venous blood at the venous sinuses on top ofthe brain.

Peripheral nervous systemThe peripheral nervous system consists of the cranialnerves, spinal nerves, and autonomic nervous system(ANS).

Message lines: Neck and aboveThe 12 pairs of cranial nerves transmit motor or senso-ry messages, or both, primarily between the brain orbrain stem and the head and neck. All cranial nerves, ex-cept the olfactory and optic nerves, exit from the mid-brain, pons, or medulla oblongata of the brain stem. (SeeA look at the 12 cranial nerves.)


Three men ofMonro

The foramen of Monro isnamed after AlexanderMonro II (1733–1817), theman who first describedit. Monro was the sec-ond professor of anato-my at the University ofEdinburgh (and the sec-ond named AlexanderMonro). He succeededhis father in this positionand was succeeded byhis own son, Alex III.


845512.qxd 8/19/08 6:16 PM Page 280

Can you hear me now?The 31 pairs of spinal nerves are named for the vertebraimmediately below each nerve’s exit point from the


A look at the 12 cranial nerves

As this illustration reveals, 10 of the 12 pairs of cranial nerves (CNs) exit from the brain stem. Theremaining two pairs—the olfactory and optic nerves—exit from the forebrain.

Olfactory (CN I) Sensory: smell

Optic (CN II) Sensory: vision

Trochlear (CN IV) Motor: extraocular eyemovement (inferior medial)

Vagus (CN X) Motor: movement of the palate,swallowing, gag reflex, activity of the thoracicand abdominal viscera, such as heart rate andperistalsis; Sensory: sensations of the throat,larynx, and thoracic and abdominal viscera(heart, lungs, bronchi, and GI tract)

Trigeminal (CN V) Sensory: transmitting stimulifrom face and head, corneal reflex; Motor:chewing, biting, and lateral jaw movements

Facial (CN VII) Sensory: taste receptors(anterior two-thirds of the tongue); Motor: facialmuscle movement, including muscles ofexpression (those in the forehead and aroundthe eyes and mouth)

Acoustic (CN VIII) Sensory: Hearing, sense ofbalance

Glossopharyngeal (CN IX) Motor: swallowingmovements; Sensory: sensations of the throat,taste receptors (posterior one-third of thetongue)

Hypoglossal (CN XII) Motor: tongue movement

Spinal accessory (CN XI) Motor: shouldermovement, head rotation

Abducens (CN VI) Motor: extraocular eyemovement

Oculomotor (CN III) Motor: extraocular eyemovement (superior, medial, and inferior lateral),pupillary constriction, upper eyelid elevation

It says here

that most of the

cranial nerves

transmit either

motor or sensoryinformation. A few,

such as the vagusnerve, do both.

845512.qxd 8/19/08 6:16 PM Page 281

spinal cord; thus, they’re designated from top to bottomas C1 through S5 and the coccygeal nerve. Each spinalnerve consists of afferent and efferent neurons, whichcarry messages to and from particular body regionscalled dermatomes.

Autonomic nervous systemThe vast ANS innervates all internal organs. Sometimesknown as visceral efferent nerves, the nerves of theANS carry messages to the viscera from the brain stemand neuroendocrine regulatory centers. The ANS has twomajor subdivisions: the sympathetic (thoracolumbar)nervous system and the parasympathetic (cranio-sacral) nervous system. (See On autonomic pilot.)

System response: GeneralSympathetic nerves called preganglionic neurons exitthe spinal cord between the levels of the first thoracicand second lumbar vertebrae. After they leave the spinalcord, these nerves enter small ganglia near the spinalcord. The ganglia form a chain that spreads the impulseto postganglionic neurons, which reach many organsand glands and can produce widespread, generalizedphysiologic responses.

System response: SpecificFibers of the parasympathetic nervous system leave theCNS by way of the cranial nerves from the midbrain andmedulla and the spinal nerves between the second andfourth sacral vertebrae (S2-S4).

After leaving the CNS, the long preganglionic fiber ofeach parasympathetic nerve travels to a ganglion near aparticular organ or gland; the short postganglionic fiberenters the organ or gland. This creates a more specific re-sponse, involving only one organ or gland.


Here are terms associated with procedures and observa-tions one might encounter in a physical examination re-lating to the neurologic system:• Absence seizure (also known as a petit mal seizure)is marked by a sudden, momentary loss of conscious-


On autonomicpilot

The autonomic nervoussystem innervates all in-ternal organs. Autonom-

ic comes from two Greekwords: auto, meaningself, and nomos, mean-ing law. So, this nervoussystem operates accord-ing to its own law, orwithout conscious con-trol.


Think of the

autonomic

nervous system

as being on

autopilot.


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C13INCREDIBLY EASY MINIGUIDE: THE BRAIN

Incredibly Easy miniguide: The brain

You really can’t

understand me unless

you’re willing to look

at my lobes.

The temporal lobe

controls hearing, languagecomprehension, andstorage and recall of

memories.

The frontal lobe

influences personality,judgment, abstract reasoning,

social behavior, languageexpression, and movement.

The parietal lobe

interprets and integratessensations, including pain,

temperature, and touch. It alsointerprets size, shape,distance, and texture.

The occipital

lobe functionsmainly to interpret

visual stimuli.

The cerebrum has right and left hemispheres. Each cerebral hemisphere is divided into four lobes.

8455CP4.qxd 8/19/08 8:07 PM Page C13



This illustration of the inferior surface of the brain shows the anterior and posterior arteries, which join with smaller arteries to formthe circle of Willis.

The carotid arteriesdivide into anterior and

middle cerebral

arteries on each side.

The vertebralarteries join

centrally to formthe basilar artery.

This circle of

arteries is known as

the circle of Willis.

Circle of Willis

The brainreceives blood

from four vessels;two internal

carotids and twovertebral arteries

(one on each side).

The anteriorcerebral arteries arejoined by the anterior

communicating

artery.

The internal carotidarteries are joined to the

posterior cerebral

arteries by the posterior

communicating

arteries.

8455CP4.qxd 8/19/08 8:07 PM Page C14

C15INCREDIBLY EASY MINIGUIDE: THE BRAIN


The dura mater isa fibrous membrane

that lines the skull andforms folds, or

reflections, thatdescend into the

brain’s fissures andprovide stability.

A fragile, fibrouslayer of moderateblood supply, the

arachnoid liesbetween the duramater and the pia

mater.

The pia mater (shown herein green) is extremely thin and

has a rich blood supply. It closelycovers the brain’s surface and

extends into its fissures.

The meninges cover and protect the brain. They consist of three layers of connective tissue—the dura mater, arachnoid, and piamater.

The subarachnoid

space, filled withcerebrospinal fluid,

separates thearachnoid and the

pia mater.

The subdural space is situatedbetween the dura mater and thearachnoid. This closed area—

commonly the site of hemorrhageafter head trauma—offers no escape

route for blood accumulation. The epidural

space lies over thedura mater.

Falx cerebri lies in thelogitudinal fissure andseparates the cerebral

hemisphere.

8455CP4.qxd 8/19/08 8:07 PM Page C15


Oculomotor (CN III):

Extraocular eye movement,pupillary constriction,upper eyelid elevation

Trigeminal (CN V):

Transmission of stimulifrom the face and head,

corneal reflex

Optic

(CN II): Vision

Vagus (CN X): Movement of thepalate; swallowing; gag reflex; activityof the thoracic and abdominal viscera,

such as heart rate and peristalsis;sensations of the throat, larynx, and

thoracic and abdominal viscera (heart,lungs, bronchi, and GI tract)

Spinal

accessory (CN XI):

Shoulder movement,head rotation

Hypoglossal

(CN XII):

Tongue movement

Trochlear

(CN IV):

Extraocular eyemovement


Abducens

(CN VI):

Extraoculareye movement

It would be hard

to study without

an optic nerve.

Acoustic

(CN VIII): Hearing,sense of balance

Olfactory

(CN I): Smell

The 12 pairs of cranial nerves transmit motor messages, sensory messages, or both, primarily between the brain or brainstem and thehead and neck.

Glossopharyngeal

(CN IX): Swallowing movements,sensations of the throat, innervation

of taste buds located on theposterior one-third of the tongue

Facial (CN VII): Innervationof taste buds of the anterior

two-thirds of the tongue, facialmuscle movement

8455CP4.qxd 8/19/08 8:07 PM Page C16

ness, typically accompanied by loss of muscle control orspasms, and a vacant facial expression. The patient mayexperience many seizures per day.• Aphasia is loss or impairment of the ability to commu-nicate through speech, written language, or signs. It typi-cally results from brain disease or trauma.• Aphonia is loss of the ability to speak.• Apraxia is complete or partial inability to perform pur-poseful movements in the absence of sensory or motorimpairment.• Ataxia is impairment of the ability to coordinate vol-untary muscle movement.• Ataxic speech is characterized by faulty formation ofsounds. It’s typically caused by neuromuscular disease.• Athetosis is a condition characterized by constant,slow, writhing, involuntary movements of the extremities,especially the hands.• Aura is the word for the sensations that occur before aparoxysmal attack, such as a seizure or migraine headache.• Battle’s sign is discoloration of the skin behind theear following the fracture of a bone in the lower skull.• Biot’s respiration is an abnormal, unpredictablebreathing pattern characterized by irregular periods ofapnea alternating with periods of four or five breaths ofthe same depth. Biot’s respiration indicates meningitis, alesion in the medulla, or increased intracranialpressure.• Bradylalia refers to abnormally slow speech,caused by a brain lesion.• Brudzinski’s sign is flexion of the hips andknees in response to passive flexion of the neck.A positive Brudzinski’s sign signals meningeal ir-ritation.• Coma is a state of unconsciousness fromwhich the patient can’t be aroused.• Decerebrate posturing is associated with alesion of the upper brain stem or severe bilaterallesions in the cerebrum. The patient typicallylies with legs extended, head retracted, arms adductedand extended, wrists pronated, and the fingers, ankles,and toes flexed.• Decorticate posturing is associated with a lesion ofthe frontal lobes, cerebral peduncles, or internal capsule.The patient lies with arms adducted and flexed, wrists


Biot’s respiration,pronounced BEE-OHZ,

is named after

Camille Biot, a 19th-

century French

doctor.

845512.qxd 8/19/08 6:16 PM Page 283

and fingers flexed on the chest, legs stiffly extended andinternally rotated, and feet plantar flexed.• Delirium is a disorientation to time and place; the pa-tient may also experience illusions and hallucinations.• Dementia is an organic mental syndrome marked bygeneral loss of intellectual abilities, with chronic person-ality disintegration, confusion, disorientation, and stupor.It doesn’t include states of impaired intellectual function-ing resulting from delirium or depression.• Dysphagia is difficulty swallowing.• Dysphasia is impairment of speech involving failure toarrange words in their proper order, usually resultingfrom injury to the speech area in the cerebral cortex.• Dyspraxia is a partial loss of the ability to perform co-ordinated movements, with no associated defect in motoror sensory functions.• A generalized tonic-clonic (grand mal) seizure isan epileptic seizure that may be preceded by an aura.This type of seizure is characterized by loss of conscious-ness and muscle spasms (tonic phase), followed by con-vulsive movement of the limbs (clonic phase).• The Glasgow Coma Scale is commonly used to assessa patient’s level of consciousness (LOC). It was designedto help determine a patient’s chances for survival and re-covery after a head injury. The scale scores three obser-vations — eye opening response, best motor response,and best verbal response. Each response receives a pointvalue. If a patient is alert, can follow simple commands,and is well-oriented, his score will total 15 points. If thepatient is comatose, his score will be 7 or less. The low-est possible score, 3, indicates deep coma and a poorprognosis.• Headache is diffuse pain that occurs in differ-ent portions of the head and is not confined toany nerve distribution area.• Hemiparesis refers to paralysis or muscularweakness affecting only one side of the body.• Hemiplegia is paralysis of one side of the body.• Intracranial pressure (ICP) is the pressurecreated by CSF in the subarachnoid space be-tween the skull and brain. ICP may increase as a result ofhead trauma, brain tumor, stroke, or infection in thebrain.• Kernig’s sign refers to resistance and hamstring mus-cle pain that occur when an examiner attempts to extend


Dysphasiafailure words is

proper order in

arrange to.

The Glasgow ComaScale was designed

to help determine a

patient’s chances for

survival and recovery

after a head injury.

845512.qxd 8/19/08 6:16 PM Page 284

a patient’s knee while the hip and knee are both flexed 90degrees. This sign is usually present in a patient withmeningitis or subarachnoid hemorrhage.• Neuralgia is severe pain in a nerve or nerves.

ReflexesReflexes, involuntary responses to stimuli, are discussedhere:• Achilles tendon reflex produces plantar flexionwhen the Achilles tendon is tapped.• Babinski’s reflex is dorsiflexion of the big toe in re-sponse to scraping the sole of the foot.• Biceps reflex causes contraction of the biceps mus-cles when the tendon is tapped.• Brachioradialis reflex is flexion and supination ofthe elbow or visible contraction of the brachioradialismuscle when the radius is tapped 11⁄8� to 2� (3 to 5 cm)above the wrist while the arm is relaxed.• Corneal reflex is closure of the eyelids when thecornea is touched.• A negative oculocephalic reflex, also known as anabsent doll’s eye sign, is an indicator of brain stem dys-function. The absence of the doll’s eye sign is detected byrapid, but gentle, turning of the patient’s head from sideto side. The eyes remain fixed in an abnormal straight-ahead position instead of moving in the direction oppo-site to which the head is turned.• Gag reflex is elicited by touching the soft palate or theback of the pharynx. The normal response is elevationof the palate, retraction of the tongue, and contractionof the constrictor muscle of the pharynx.• Knee-jerk reflex is a kick reflex produced bysharply tapping the patellar ligament. It’s also knownas the patellar reflex.• Pupillary reflex is contraction of the pupils in re-sponse to light.• Triceps reflex is visible contraction of the tricepsor extension of the arm when the triceps tendon istapped above the elbow while the arm is flexed.


Sorry!

845512.qxd 8/19/08 6:16 PM Page 285

Diagnostic tests

Diagnostic tests associated with the neurologic systeminclude radiographic and imaging studies, electrophysio-logic studies, and CSF and blood tests.

Radiographic and imaging studiesHere are some common radiographic and imaging studies:• Cerebral angiography is a radiographic procedure inwhich radiopaque contrast is injected into blood vesselsto allow visualization of the vascular system of the brain.• Computed tomograph (CT) combines radiographyand computer analysis of tissue density. When used to di-agnose neurologic disorders, it produces images of thestructures inside the skull and spinal cord.• Digital subtraction angiography (DSA) traces thecerebral vessels by means of a type of computerized fluo-roscopy. The technician takes an image of the area beingstudied and stores it in the computer’s memory. Addition-al images are taken after the patient receives a contrastmedium. By subtracting the original picture from the lat-er images, the computer produces high-resolution imagesfor interpretation.• Echoencephalography is a diagnostic technique thatinvolves the use of ultrasound waves to study structureswithin the brain.• Magnetic resonance angiography (MRA) is a nonin-vasive method of scanning that allows visualization ofblood flowing through the cerebral vessels.• Magnetic resonance imaging (MRI), also called nu-clear magnetic resonance, is a noninvasive method ofscanning with an electromagnetic field and radio waves.It provides visual images of structures on a computerscreen.• In myelography, dye or air is injected into the patient’ssubarachnoid space after lumbar puncture. X-rays arethen taken.• Pneumoencephalography (PEG) enables visualiza-tion the fluid-filled structures of the brain after CSF is in-termittently withdrawn through lumbar puncture and re-placed by air, oxygen, or helium. (See Getting aroundPEG.)


The root echo in

echoencephalographytells you that this

test uses sound

waves.

Getting aroundPEG

Pneumoencephalogra-

phy is a long word, but itcan easily be brokendown.

Pneumo- means air.The prefix en- meanswithin, and -cephal- is aGreek term for head. So-encephal- literallymeans within the headand thus refers to thebrain. The suffix -graphy

refers to a method ofrecording, in this case X-ray photography. So, theterm means X-ray pho-tography of air (or gas)in the brain.


845512.qxd 8/19/08 6:16 PM Page 286

• A positron emission tomography (PET) scan isused to determine the brain’s metabolic activity after theinfusion of radioactive materials.• In skull X-rays, high-energy radiography is used to de-tect fractures, bony tumors, or vascular abnormalities.They’re typically taken from two angles: anteroposteri-or and lateral. Waters’ projection is used to examinethe frontal and maxillary sinuses, facial bones, and eyeorbits. Towne’s projection is used to examine the occip-ital bone.• Spinal X-rays are obtained to detect spinal fractures,displacement of the spine, destructive lesions, structuralabnormalities, and other conditions.• Stereotaxic neuroradiography is an X-ray procedureused during neurosurgery to guide a needle or electrodesinto a specific area of the brain. (See Understandingstereotaxic neuroradiography.)

Electrophysiologic studiesHere are some common electrophysiologic studies asso-ciated with the neurologic system:• Electroencephalography, also called EEG, recordsthe brain’s continuous electrical activity.• Evoked potential testing evaluates the integrity ofvisual, somatosensory, and auditory nerve pathways bymeasuring evoked potentials—the brain’s electrical re-sponse to stimulation of the sensory organs or peripheralnerves. This type of testing is used to detect neurologiclesions and to evaluate multiple sclerosis as well as vari-ous vision and hearing disorders.• Magnetoencephalography is a noninvasive test thatdirectly measures the magnetic fields produced by elec-trical currents in the brain.

CSF and blood testsCSF analysis is performed on CSF that’s removed duringa lumbar puncture (aspiration of CSF by insertion of aneedle into the L3-4 or L4-5 interspace). Three commontests of CSF and blood are described here:• The amyloid beta-protein precursor test checksCSF for levels of a substance that produces the protein

287DIAGNOSTIC TESTS

Understandingstereotaxicneuroradiog-raphy

Stereotaxic neuroradi-

ography is easy to un-derstand when youbreak it down into itscomponents. Stereo- is afamiliar term from theGreek language thatrefers to somethingthat’s solid, meaning ithas three dimensions.Taxic refers to move-ment in response to astimulus. Neuro- refersto the nervous system.Radiography is an X-raystudy. Thus, stereotaxic

neuroradiography in-volves movement (of aneedle or electrode) inthree dimensions ac-companied by X-ray pho-tography of the brain.


845512.qxd 8/19/08 6:16 PM Page 287

plaques seen in the brains of patients with Alzheimer’sdisease.• Coccidioidomycosis antibodies is a blood test toidentify a fungal infection that affects CNS and other ar-eas of the body.• CSF analysis is used to detect the presence of blood,infection, and other abnormalities.

Disorders

This section discusses brain and spinal cord disorders,cranial nerve disorders, degenerative disorders, headtrauma, vascular disorders, and miscellaneous neurologicdisorders.

Brain and spinal cord disordersHere are some common brain and spinal cord disorders,including CNS infections and neural tube defects:• Cerebral palsy is a chronic disorder of motor functionresulting from nonprogressive brain damage or a brain le-sion.• Epilepsy refers to a group of neurologic disordersmarked by uncontrolled electrical discharge from thecerebral cortex and typically manifested by seizures withclouding of consciousness. Status epilepticus describesa continuous seizure state, which is life-threatening.• Hydrocephalus is a condition marked by excess CSFwithin the brain’s ventricles. Two types exist; they’renamed according to their causes. Noncommunicatinghydrocephalus results from obstruction of CSF flow.Communicating hydrocephalus is caused by faulty re-absorption of CSF. (See Too much water.)• Migraine headache is a very painful, throbbingheadache commonly associated with sensitivity to lightand sound. In some people, the headache is preceded byan aura.• A subarachnoid hemorrhage is an intracranial hem-orrhage into the subarachnoid space.• Subdural hematoma is accumulation of blood in thesubdural space.


Too much water

Hydrocephalus is a con-dition marked by excesscerebrospinal fluid with-in the brain’s ventricles.The term hydrocephalus

originates from theGreek words hydro,

meaning water or fluid,and kephale, meaninghead.


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CNS infectionsCNS infections include encephalitis, meningitis, rabies,and others:• Brain abscess, also known as an intracranial ab-scess, is a free or encapsulated collection of pus, usuallyfound in the temporal lobe, cerebellum, or frontal lobe.• Encephalitis is an inflammatory disorder of the brainthat’s commonly caused by the bite of an infected mos-quito.• Meningitis refers to the inflammation of the meningesof the brain and spinal cord caused by bacterial, viral, orfungal infection.• Myelitis is an inflammation of the spinal cord.• Poliomyelitis is an acute viral infection and inflamma-tion of the gray matter of the spine, usually caused by po-liovirus.• Rabies is an acute, usually fatal CNS disease spread byanimals to people through contaminated saliva, blood, ortissue. (See Afraid of the water.)

Neural tube defectsNeural tube defects are serious birth defects involvingthe spine or brain. They result from failure of the neuraltube to close approximately 28 days after conception.

The most common forms of neural tube defects arespina bifida, anencephaly, and encephalocele:• In anencephaly, part of the top of the skull and all orpart of the brain are missing.• In encephalocele, a saclike portion of the meningesand brain protrudes through a defective opening in theskull.• Spina bifida cystica is incomplete closure of one ormore vertebrae, which causes spinal contents to protrudein an external sac. The spinal cord is usually normal.• Spina bifida with meningocele is a form of spina bi-fida in which the sac contains meninges and CSF.• Spina bifida with myelomeningocele (meningo-myelocele) is a form of spina bifida in which the saccontains meninges, CSF, and a portion of the spinal cordor nerve roots.

289DISORDERS

Afraid of thewater

Rabies is also calledhydrophobia—meaningfear of water—becausethis condition producesmuscle spasms in thethroat when the patientdrinks water.


Remember,

-itis refers to

inflammation. So

meningitis is an

inflammation of

the meninges.

845512.qxd 8/19/08 6:16 PM Page 289

Cranial nerve disordersCranial nerve disorders include Bell’s palsy and trigemi-nal neuralgia:• Bell’s palsy is a unilateral facial paralysis of suddenonset, attributable to a lesion of the facial nerve. It’s gen-erally not permanent.• Trigeminal neuralgia, also called tic douloureux, isa painful disorder affecting one or more branches of thefifth cranial (trigeminal) nerve. With stimulation of a trig-ger zone, the patient experiences paroxysmal attacks ofexcruciating facial pain.

Degenerative disordersDegenerative disorders of the brain include Alzheimer’sdisease, multiple sclerosis, Parkinson’s disease, and oth-ers:• Alzheimer’s disease produces three hallmark featuresin the brain: neurofibrillary tangles, neuritic plaques, andgranulovascular degeneration. Early signs progress to se-vere deterioration in memory, language, and motor func-tion.• Amyotrophic lateral sclerosis, also called LouGehrig disease, is an incurable disease affecting thespinal cord and the medulla and cortex of the brain. It’scharacterized by progressive degeneration of motor neu-rons. This degeneration leads to weakness and wasting ofthe muscles, increased reflexes, and severe musclespasms. Death typically occurs within 2 to 5 years.• Huntington’s disease, also called Huntington’schorea, is a hereditary disorder that causes degenerationin the cerebral cortex and basal ganglia. Degenerationleads to chronic, progressive chorea (rapid, jerky move-ments) and mental deterioration and ends with dementiaand death.• Multiple sclerosis is a progressive demyelination ofthe white matter of the brain and spinal cord that resultsin weakness, incoordination, paresthesia, speech distur-bances, and visual complaints.• Myasthenia gravis is abnormal muscle weakness andfatigability, especially in the muscles of the face andthroat, resulting from a defect in the conduction of nerveimpulses at the myoneural junction.


Asthenia is the

Greek word for

weakness.

Myasthenia gravis is

abnormal muscle

weakness, particularly

in the face and

throat.

845512.qxd 8/19/08 6:16 PM Page 290

• Parkinson’s disease is a slow-progressing, degenera-tive neurologic disorder that produces muscle rigidity,akinesia, and involuntary tremor.

Head traumaHead trauma can range from concussion to tentorial her-niation:• Cerebral contusion is a bruising of the brain tissue asa result of a severe blow to the head. More severe than aconcussion, a contusion disrupts normal nerve functionin the bruised area and may cause loss of consciousness,hemorrhage, edema, and even death.• Concussion, the most common head injury, resultsfrom a blow to the head that’s hard enough to jostle thebrain and cause it to strike the skull. This causes tempo-rary neural dysfunction and a change in LOC.• An epidural hematoma is the rapid accumulation ofblood between the skull and dura mater.• Tentorial herniation occurs when injured brain tis-sue swells and squeezes through the tentorial notch (anarea that contains the midbrain), constricting the brainstem.

Vascular disordersVascular disorders include cerebral aneurysm, cerebro-vascular accident, and others:• Arteriovenous malformation (AVM) is a congenitalmalformation characterized by a tangled mass of dilatedcerebral vessels that form an abnormal communicationbetween the arterial and venous systems.• A cerebral aneurysm is a localized dilation (balloon-ing) of a cerebral artery caused by weakness in the arteri-al wall.• Cerebrovascular accident (CVA) is a condition ofsudden onset in which a cerebral blood vessel is occlud-ed by an embolus or cerebrovascular hemorrhage. Theresulting ischemia of brain tissue normally perfused bythe affected vessel may lead to permanent neurologicdamage. (See CVA substitutes.)• A transient ischemic attack (TIA) is a recurrentneurologic episode lasting less than 1 hour. It doesn’tcause permanent or long-lasting neurologic deficit but is

291DISORDERS

CVA substitutes

A cerebrovascular acci-

dent (CVA) is rarely re-ferred to by its propername in the real world.Rather, it’s referred to as a “stroke” or “brainattack.”

The realworld

845512.qxd 8/19/08 6:16 PM Page 291

usually considered a warning sign of an impendingstroke.

Miscellaneous neurologic disordersOther neurologic disorders include Reye’s syndrome,tetanus, and Tourette syndrome:• Guillain-Barré syndrome is an acute, febrile polyneu-ritis that sometimes occurs after a viral infection. It’smarked by rapidly ascending paralysis that begins asweakness and paresthesia of the legs.• Neurofibromatosis is a genetic trait characterized bythe presence of multiple neurofibromas (fibrous tumorsof peripheral nerves, resulting from abnormal prolifera-tion of Schwann cells) of the nerves and skin, café-au-lait(light, coffee-colored) spots on the skin and, sometimes,developmental anomalies of the muscles, bones, and vis-ceral tissue.• Reye’s syndrome is usually an acute childhood illnessthat causes fatty infiltration of the liver with concurrentelevated blood ammonia levels, encephalopathy, and in-creased ICP. Although a definitive cause hasn’t been de-termined, it’s associated with the use of aspirin-contain-ing medications in the treatment of viral illnesses.• Tetanus is an acute, commonly fatal infection causedby the anaerobic bacillus Clostridium tetani, which usu-ally enters the body through a contaminated puncturewound.• Tetany is hyperexcitability of nerves and prolongedcontraction of muscles caused by low calcium levels.• Tourette syndrome is a condition characterized by fa-cial and vocal tics, generalized lack of coordination, andrarely coprolalia (an uncontrollable urge to utter ob-scenities).

Treatments

The terminology discussed here describes treatments (in-cluding surgeries) that may be employed when caring fora patient with a neurologic disorder.


845512.qxd 8/19/08 6:16 PM Page 292

Brain treatments and monitoring toolsTreatments include craniotomy, lobotomy, placement of aventriculoperitoneal shunt, and different methods of ICPmonitoring:• Cerebellar stimulator implantation involves thesurgical implantation of electrodes into a patient’s brainto regulate uncoordinated neuromuscular activity usingelectrical impulses. This treatment has also been used toprevent seizures.• Craniectomy is removal of a part of the skull.• A craniotomy is the creation of a surgical incision intothe skull to expose the brain for treatment.• Hemicraniectomy is the removal of the skull to ex-pose half of the brain in preparation for surgery.• Intracranial hematoma aspiration is performed toreduce high ICP caused by a collection of blood aroundthe surface of the brain. A craniotomy must be performedto access the brain.• Lobectomy is removal of a lobe of the brain.• Lobotomy is incision into the frontal lobe of the brainthrough holes drilled into the skull.• Stereotactic surgery provides three-dimensimal im-ages that guide the surgeon in removal of small brain tu-mors and abscesses drainage of hematomas, repair ofAVMs, and ablation for Parkinson’s disease.• A ventriculoperitoneal shunt is a surgical treatmentfor hydrocephalus in which a catheter drains CSF fromthe ventricular system for absorption. The shunt extendsfrom the cerebral ventricle to the scalp, where it’s tun-neled under the skin and drains into the peritoneal cavity.Shunting lowers ICP and prevents brain damage by drain-ing excess CSF or relieving blockage.• In volumetric interstitial brachytherapy, radioac-tive materials are implanted into the skull and left inplace for several days to deliver radiation to a brain tumor.

Intracranial pressure monitoringICP monitoring is an important part of neurologic treat-ment because increased ICP can lead to fatal brain herni-ation. Invasive ICP monitoring is accomplished in one ofseveral ways:

293TREATMENTS

Lobectomy

or lobotomy?

I’m confused.

In a lobectomy, alobe of the brain is

excised. Lobotomyinvolves incision, not

excision.

845512.qxd 8/19/08 6:16 PM Page 293

• An epidural probe is a tiny fiber-optic sensor insertedin the brain’s epidural space through a burr hole (a holedrilled into the skull).• A subarachnoid screw is a small, hollow, steel screwwith a sensor tip that’s inserted through a burr hole. It’sused to monitor pressure in the subarachnoid space.• A ventricular catheter, consisting of a small polyeth-ylene cannula and an external drainage and collectionsystem, is inserted through a burr hole into a lateral ven-tricle.

Spinal and nerve surgeryHere are some common surgeries performed on the spineor spinal nerves:• Chordotomy is any operation on the spinal cord.• Gamma knife surgery is a noninvasive procedure thatuses beams of gamma radiation to precisely target andtreat brain lesions such as brain tumors, vascular malfor-mations, and functional disorders such as trigeminal neu-ralgia.• Myelomeningocele repair is performed to correct acongenital spinal defect as a means of preventing infec-tion. The surgeon isolates neural tissue from the rest ofthe myelomeningocele sac and fashions a flap from sur-rounding tissue.• Neurectomy is removal of part of a nerve.• Neuroplasty is surgical repair of a nerve.• In sympathectomy, a surgeon resects a sympatheticnerve or ganglion.• Vagotomy is transection of the vagus nerve.

Other neurologic treatmentsHere are some other common neurologic treatments:• AVM embolization is a minimally invasive techniquethat’s used to treat AVMs when surgery isn’t an option. Tolower the risk of rupture and hemorrhage, a flexiblecatheter is threaded into the AVM site, and small, heat-resistant silicon beads or a rapid-setting plastic polymeris inserted. The beads or polymer lodge in the feederartery and occlude blood flow to the AVM.• An induced barbiturate coma is a treatment of last re-sort for a patient experiencing sustained or acute episodes


845512.qxd 8/19/08 6:16 PM Page 294

of high ICP. The patient receives large doses of a short-acting barbiturate, such as pentobarbital, to induce acoma. The drug reduces the metabolic rate and cerebralblood volume, possibly reducing ICP and protecting cere-bral tissue.• Drug therapy for neurologic disorders includes theuse of anticonvulsants to control seizures, cortico-steroids to decrease inflammation and edema, osmoticdiuretics to promote diuresis and reduce cerebral ede-ma, and antibiotics to treat infection.• Plasmapheresis is a process by which the blood iscleansed of harmful substances. In this procedure, plas-ma is removed from withdrawn blood, and the formedblood elements are reinfused after being mixed with aplasma replacement solution. In some methods, the plas-ma is filtered to remove a specific disease mediator andis then returned to the patient. Plasmapheresis is used totreat Guillain-Barré syndrome, multiple sclerosis, andmyasthenia gravis.

295TREATMENTS

Okay, listen up. You

anticonvulsants,

corticosteroids,

osmotic diuretics, and

antibiotics may be

needed to treat

neurologic disorders.

845512.qxd 8/19/08 6:16 PM Page 295


Vocabulary builders

Across

3. Neurons outside the brain8. Carries impulses away from thecell9. Plural of nucleus

13. “Water on the brain”14. Another name for sensory neu-

rons

16. Acronym for the medical termfor stroke

17. Records the brain’s electricalactivity21. Membranes enclosing the CNS23. Basic cells of the nervous sys-tem25. Type of headache preceded byan aura

Down

1. First cranial nerve2. Controls body temperature4. Arteriovenous malformation ab-breviation5. Serves as a bridge6. Central nervous system abbrevi-ation7. Carries impulses to the cell10. Another name for mesen-

cephalon

11. Infection of the meninges12. Largest part of the brain

15. Another name for motor neu-

rons

18. Sheath covering nerve cells19. Cerebrospinal fluid abbrevia-tion20. The brain’s switchboard22. Gluelike cells24. Second cranial nerve


1 2

3 4 5

6 7

8 9

10

11 12

13

14 15

16 17

18

19 20

21 22

23 24

25

At a crossroadsCompleting this crossword puzzle will help test your nerve withthe nervous system. Good luck!

845512.qxd 8/19/08 6:16 PM Page 296




1. The most common head injury is a _____.

2. A patient who loses the ability to speak or write has _____.

3. Patients commonly experience an _____ just before a migraine headache.

4. Creation of a surgical incision into the skull is a _____.

5. Holes drilled into the skull are known as _____ holes.

6. A subarachnoid screw is used to monitor a patient’s __________ __________.

7. __________ __________ is the surgical treatment of hydrocephalus.

8. Plasmapheresis is the therapeutic removal of _____ from the patient’s body.

Talking in circlesUse the clues below to fill in the blanks with the appropriate word. Then unscramblethe circled letters to find the answer to the question posed at left.

1. ____ ____ ____ ____ ____ ____

2. ____ ____ ____ ____ ____ ____ ____

____ ____ ____ ____ ____ ____ ____ ____ ____

3. ____ ____ ____ ____ ____ ____ ____ ____

4. ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____

5. ____ ____ ____ ____ ____ ____

6. ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____

1. Highly specialized cell that detects and transmits stimuli electromechanically2. Autonomic reflex center that maintains homeostasis, regulating respiratory, vasomotor, and cardiac functions3. Cover and protect the cerebral cortex and spinal column4. Controls or affects body temperature, appetite, water balance, pituitary secretions, and emotions5. Acute, usually fatal CNS disease spread by animals to people through contaminated saliva, blood, or tissue6. An inflammatory disorder of the brain commonly caused by the bite of an infected mosquito

I get a lot of

support, nourishment,

and protein from my

nonneuronal buddy

cells. Do you know

which ones I mean?

845512.qxd 8/19/08 6:16 PM Page 297


1. Concussion; 2. Aphasia; 3. Aura; 4. Craniotomy; 5. Burr;6. Intracranial pressure; 7. Ventricular shunting; 8. Plasma

Finish line

1. Neuron; 2. Medulla oblongata; 3. Meninges;4. Hypothalamus; 5. Rabies; 6. Encephalitis

Answer to puzzle—Neuroglia

Talking in circles

At a crossroads

Answers

1O

2H

3G

4A N G L I A Y

5P

V F6C P O

7D

M8A X O N O

9N U C L E I

10M C S T S N

I T11M H

12C D

13H Y D R O C E P H A L U S E R

B R N L R I

R Y I14A F F

15E R E N T

16C V A N M F B

17E E G

I G U F R

N18M I S E U

Y T19C R M

20R

21M E N I N

22G E S E A

L S L F23N E U R

24O N S

I I T P

N A T

L25M I G R A I N E

C My brain got

a great workout

from this

chapter!

845512.qxd 8/19/08 6:16 PM Page 298

Endocrine structure and function

The endocrine system controls complicated body activi-ties by secreting chemical substances into the circulatorysystem. The major components of the endocrine systemare glands (specialized cell clusters or organs) and hor-mones (chemical substances secreted by the glands inresponse to stimulation). (See Pronouncing key endo-crine system terms, page 300.)

Glands in a major keyThe major glands of the endocrine system are the:• pituitary gland• thyroid gland• parathyroid glands• adrenal glands• pancreas• pineal body• thymus. (See Endocrine system structures, page 301.)

13

Health assessmentEndocrine system

Just the facts


♦ terminology related to the structure and function ofthe endocrine system


♦ tests that help diagnose common endocrine disor-ders

♦ endocrine system disorders and their treatments.

Memoryjogger

Repeatingthis silly

phrase—“Your pit-pat is a pip”—canhelp you rememberthe major glands ofthe endocrine sys-tem:

PItuitary

Thyroid

Parathyroid

Adrenal

Thymus

PIneal body

Pancreas.

845513.qxd 8/19/08 6:23 PM Page 299

Pituitary glandThe pituitary gland, also known as the hypophysis, isno larger than a pea and lies at the base of the brain in adepression of the sphenoid bone called the sella turcica.

Cover and connectionThe pituitary diaphragm, an extension of the duramater (the membrane covering the brain), extends overthe pituitary gland and protects it. The pituitarystalk, a stemlike structure, provides a connec-tion to the hypothalamus.

Master glandThe pituitary gland is also called the “mastergland” because it controls all the other glands. It’sdivided into two regions: the anterior pituitarylobe and the posterior pituitary lobe.

300ENDOCRINE SYSTEM

Below is a list of key terms related to the endocrine systemalong with the correct ways to pronounce them.


Pronouncing key endocrinesystem terms

Acromegaly

Adenohypophysis

Hyperaldosteronism

Luteinizing hormone

Oxytocin

Radioimmunoassay

Thymopoietin

Thyrotoxicosis factitia

Triiodothyronine

ACK-ROH-MEG-UH-LEE

ADD-EH-NOH-HEYE-PAHF-IH-SIS

HEYE-PER-AL-DOS-TER-OHN-IZM

LOO-TEE-I-NEYE-ZING HOR-MOHN

OCH-SEE-TOE-SIN

RAY-DEE-OH-IM-YOU-NOH-AHS-SAY

THEYE-MOH-POY-EH-TIN

THEYE-ROH-TOK-SI-KOH-SIS FAK-TISH-SHUH

TREYE-EYE-O-DOH-THEYE-ROH-NEEN

Hypo- means

beneath; -physis

means to grow.

So…the

hypophysis(pituitary

gland) “grows”

beneath me?

845513.qxd 8/19/08 6:23 PM Page 300

Courtesy of the anterior pituitaryThe largest region of the pituitary gland, the anterior pi-tuitary lobe (adenohypophysis) produces at least sev-en hormones. (See The history of pituitary, page 302.)These are:• Growth hormone (GH), or somatotropin, promotesthe growth of bony and soft tissues.• Thyrotropin, or thyroid-stimulating hormone(TSH), influences secretion of thyroid hormone.

301ENDOCRINE STRUCTURE AND FUNCTION

Endocrine glands secrete hormones directly into the bloodstream to regulate body function. Thisillustration shows the locations of most of the major endocrine glands.


Endocrine system structures

Pineal body(PIN-EE-UHL)

Pituitary gland(PUH-TOO-UH-TAIR-EE)

Thyroid gland

Thymus(THY-MUHS)

Adrenal glands

Pancreas(PAN-KREE-UHS)

845513.qxd 8/19/08 6:23 PM Page 301

• Corticotropin stimulates the adrenal cortex to pro-duce cortisol. (See Turning on to tropins.)• Follicle-stimulating hormone (FSH) stimulates thegrowth of graafian follicles. It also stimulates estrogensecretion in females and the development of sperm cellsin males.• Luteinizing hormone (LH) stimulates maturation ofthe ovarian follicle and the ovum and ovulation in fe-males. It stimulates production and secretion of testos-terone in males.• Prolactin (PRL), or mammotropin, stimulates breastdevelopment during pregnancy and is responsible for theproduction of milk.• Melanocyte-stimulating hormone is responsible forthe formation of melanin pigment in the skin.

The posterior plays its partThe posterior pituitary lobe (neurohypophysis)makes up about 25% of the gland. It stores and releasesantidiuretic hormone (ADH) and oxytocin after they’reproduced by the hypothalamus. ADH, also called vaso-pressin, stimulates water resorption by the kidneys to lim-it the production of large volumes of urine. Oxytocin stim-ulates the ejection of breast milk into the mammary ducts.It also stimulates contraction of the uterus during labor.

Thyroid glandThe thyroid gland lies directly below the larynx and par-tially in front of the trachea. Its two lobes are joined by a

302ENDOCRINE SYSTEM

Thyroid literally

means shield-

shaped and refers

to the shields

that ancient

Greek soldiers

carried.

The word pituitary derives from the Latin word pituita, whichmeans phlegm (mucus) and was based on the belief that phlegmwas produced by this gland. In the “Doctrine of the Four Hu-mors,“ a theory of physiology and psychology commonly heldduring the 17th century, too much of the humor phlegm in one’sbody resulted in a listless, cold, apathetic personality—in otherwords, a phlegmatic individual.


The history of pituitary

845513.qxd 8/19/08 6:23 PM Page 302

narrow tissue bridge called the isthmus, which gives thethyroid its butterfly shape.

Two lobes as oneThe lobes function as one unit to produce the thyroidhormones thyroxine (T4), triiodothyronine (T3), andthyrocalcitonin (calcitonin). T3 and T4 are collectivelyknown as thyroid hormones. They influence manymetabolic processes, including cellular heat production,protein synthesis, and carbohydrate metabolism. Calci-tonin lowers blood calcium and phosphate levels byblocking the resorption of bone, where calcium and phos-phate are stored.

Too much of a good thingIodine is an essential element of thyroid hormones;many thyroid disorders are caused by overproduction ofthyroid hormones and the iodine-containing substancesthey contain. The iodine within thyroid hormones com-bines with a protein in the blood to form protein-boundiodine. The components separate, however, when thehormone enters the tissues.

Parathyroid glandsFour parathyroid glands lie on the posterior surface of thethyroid, one on each corner. (Para- means alongside.)

Checking calciumLike the thyroid lobes, the parathyroid glands work to-gether as a single unit, producing parathyroid hormone(PTH). This hormone regulates the calcium and phos-phorus content of the blood and bones. PTH increasesblood calcium and phosphate levels through bone resorp-tion. It antagonizes (works against) the hormone calci-tonin. Together, these two hormones maintain calciumbalance in the blood.

Adrenal glandsThe two adrenal glands sit on top of the two kidneys.Each gland contains two distinct structures that functionas separate endocrine glands.


Turning on totropins

The word tropin, ortrophin, appears in thenames of a number ofhormones produced bythe pituitary gland (forexample, somatotropinand mammotropin). Theword derives from aGreek word meaning toturn. In reference to ahormone, the sense isthat a tropin turns orchanges something.


845513.qxd 8/19/08 6:23 PM Page 303

Mandatory medullaThe inner portion, or medulla, produces the catecho-lamines epinephrine and norepinephrine. Becausethese hormones are vital to the autonomic nervous sys-tem, the adrenal medulla is also considered a neuroen-docrine structure. The adrenal medulla is essential to life,but the cortex, the much larger outer layer, isn’t.

Zoning inThe cortex has three zones and produces hormonescalled corticoids:• The outermost zone is the zona glomerulosa, whichproduces mineralocorticoid hormones, primarily aldo-sterone.• The zona fasciculata, the middle and largest zone,produces glucocorticoids and small amounts of the sexhormones estrogen and androgen.• The inner zone, the zona reticularis, produces mainlyglucocorticoids as well as some sex hormones.

Classifying corticoidsThe corticoid hormones are classified into threegroups:• Glucocorticoids are secreted mainly by the zonafasciculata and include cortisol (hydrocortisone)and corticosterone. These hormones affect all cellsin the body but specialize in controlling the metabo-lism of carbohydrates, fats, and proteins; stress resis-tance; antibody formation; lymphatic functions; andrecovery from injury and inflammation.• Mineralocorticoids are secreted by the cortex andcontrol the regulation and secretion of sodium and potas-sium. Aldosterone is the principle mineralocorticoidand is responsible for electrolyte and water balance.• Sex hormones are secreted by the zona reticularisand the zona fasciculata. They include small amounts ofthe male hormone androgen (also present in smalleramounts in females), which promotes such secondarysex characteristics as facial hair and a low-pitched voice.

No corticotropin? Can’t secrete.The adrenal cortex can’t secrete androgens and cortisolwithout the pituitary hormone corticotropin.

304ENDOCRINE SYSTEM

Get me some

glucocorticoids.

They specialize in

helping me

recover from

injury.

845513.qxd 8/19/08 6:23 PM Page 304

PancreasThe pancreas lies along the posterior of the abdominalwall in the upper left quadrant behind the stomach. Theislets of Langerhans, which perform the endocrinefunctions of this gland, contain specialized cells that se-crete hormones.

Products of the pancreasPancreatic hormones include:• insulin, the hormone responsible for the storage and useof carbohydrates and for decreasing the body’s blood glu-cose levels; it’s produced by beta cells in the pancreas• glucagon, which increases blood glucose levels and isproduced by alpha cells in the pancreas• somatostatin, a neurotransmitter released by deltacells in the pancreas that inhibits the release of glucagonand insulin.

Pineal bodyThe tiny pineal body lies at the back of the third ventri-cle of the brain and is a neuroendocrine gland. (See Pin-ing away for the pineal body.)

Makin’ melatoninThis gland produces the hormone melatonin, which isinvolved in the reproductive system and the body’s circa-dian (24-hour) rhythms.

ThymusLocated below the sternum, the thymus contains lym-phatic tissue.

Extra! Extra! Get your T cells hereAlthough the thymus produces the hormones thymosinand thymopoietin, its major role involves the immunesystem. T cells, important in cell-mediated immunity, arecreated within the thymus.


The islets of

Langerhans are

named for Paul

Langerhans, the

German pathologist

who first described

these structures in

1869.

Pining away forthe pineal body

The name pineal is de-rived from the structure’sresemblance to a pinecone.


845513.qxd 8/19/08 6:23 PM Page 305


These physical findings are significant in the diagnosis ofendocrine disorders:• Buffalo hump is an accumulation of cervicodorsalfat (fat in the neck and back). The condition may indi-cate hypercortisolism or Cushing’s syndrome.• Exophthalmos is the abnormal protrusion of one orboth eyeballs. The condition is sometimes the result ofthyrotoxicosis (hyperthyroidism).• A goiter is an enlarged thyroid gland, usually evidentas swelling in the front of the neck.• Hirsutism is an excessive growth of dark hair. Its oc-currence on a woman’s body results from excessive an-drogen production.• Moon face, usually caused by hypercortisolism, re-sults in marked roundness of the face, double chin, and afullness in the upper lip.• Polydipsia is excessive thirst, a symptom of diabetesmellitus.• Polyphagia is excessive hunger, also a symptom of di-abetes mellitus.• Polyuria is the increased excretion of urine by the kid-neys; it’s a sign of diabetes mellitus and diabetes in-sipidus.

Diagnostic tests

Many diagnostic tests and studies are available to assesthe function of the endocrine system and to detect relat-ed disorders. These tests include serum studies, urinestudies, and radiologic and other imaging tests.

Serum studiesSpecific tests are used to measure the blood levels of hor-mones and other substances and to monitor the functionof endocrine glands:• A fasting plasma glucose test is used to measureplasma glucose levels after a 12-hour fast. This test iscommonly used to screen for diabetes mellitus.

306ENDOCRINE SYSTEM

Ack!

Polydipsia is

excessive

thirst.

845513.qxd 8/19/08 6:23 PM Page 306

• Glycosylated hemoglobin monitoring provides infor-mation about the average blood glucose level during thepreceding 2 to 3 months. This test requires one venipunc-ture every 3 to 6 months to evaluate long-term effective-ness of diabetes therapy. This test is also known as he-moglobin A1C, or HbA1C.• The oral glucose tolerance test measures plasma andurine glucose levels hourly for 3 hours after ingestion ofglucose. This test assesses insulin secretion and thebody’s ability to metabolize glucose.• Quantitative analysis of plasma catecholamines isused to test for adrenal dysfunction.• Quantitative analysis of plasma cortisol levels is used totest for pheochromocytoma or adrenal medullary tumors.• The plasma LH test, typically ordered for anovulationand infertility studies in women, is a quantitative analysisof plasma LH.• Provocative testing stimulates an underactive glandor suppresses an overactive gland, depending on the pa-tient’s suspected disorder. A hormone level that doesn’tincrease despite stimulation confirms primary hypofunc-tion. Hormone secretion that continues after suppressionconfirms hyperfunction.• Radioimmunoassay (RIA) is the technique used todetermine most hormone levels. In this test, blood orurine (or a urine extract) is incubated with the hormone’santibody and a radiolabeled hormone tracer (antigen).Antibody-tracer complexes can then be measured. (SeeDissecting radioimmunoassay.)• Serum calcium analysis measures blood levels of cal-cium to detect bone and parathyroid disorders.• Serum FSH analysis measures gonadal function, espe-cially in women.

307DIAGNOSTIC TESTS

Indirect tests

measure the

substance a

particular

hormone controls,

rather than the

hormone itself.

The word radioimmunoassay can be broken down into threereadily understandable units: radio- refers to the radioactivetracer, -immuno- refers to the hormone’s antibody (which cre-ates an immunologic response), and assay means test.


Dissecting radioimmunoassay

845513.qxd 8/19/08 6:23 PM Page 307

• The serum human growth hormone (hGH) test is aquantitative analysis of plasma hGH levels that detectshyposecretion or hypersecretion of this hormone.• Serum phosphate analysis measures serum levels ofphosphate, the primary anion in intracellular fluid.• Serum PTH measurement evaluates parathyroid hor-mone function.• Serum TSH levels are measured by RIA, which can de-tect primary hypothyroidism and determine whether thehypothyroidism results from thyroid gland failure or frompituitary or hypothalamic dysfunction.• T3 measurement determines total serum content of T3to investigate thyroid dysfunction.• T4 measurement determines the total circulating T4 lev-el, which helps diagnose thyroid disorders.

Urine studiesThese tests are used to analyze urine samples for evi-dence of endocrine dysfunction:• Catecholamine analysis utilizes a 24-hour urine speci-men to measure levels of the major catecholamines—epi-nephrine, norepinephrine, and dopamine—to assessadrenal medulla function.• 17-hydroxycorticosteroid (17-OHCS) tests measureurine levels of 17-OHCS—metabolites of the hormonesthat regulate glyconeogenesis.• 17-ketosteroid (17-KS) assays determine urine lev-els of 17-KS. This test is used to diagnose adrenal dys-function.

Radiologic and other imaging testsThese tests are used to create images of body structureand assess function:• Computed tomography (CT) scanning provideshigh-resolution, three-dimensional images of a gland’sstructure by registering radiation levels absorbed by tis-sues.• Magnetic resonance imaging (MRI) uses magneticand radiofrequency waves. The deflection of the waves isinterpreted by computer to provide detailed, three-dimen-sional images of soft tissues.

308ENDOCRINE SYSTEM

Get this man

some water.

He’s scheduled

for a

catecholamine

analysis.

845513.qxd 8/19/08 6:23 PM Page 308

• A radioactive iodine uptake test evaluates thyroidfunction by measuring the amount of orally ingested io-dine isotope that accumulates in the thyroid.• In radionuclide thyroid imaging, the thyroid is stud-ied with a gamma camera after the patient receives a ra-dioisotope.• Thyroid ultrasonography is a noninvasive procedureused to detect cysts and tumors of the thyroid by direct-ing ultrasonic waves at the gland.

Disorders

Endocrine problems are caused by hyperfunction, re-sulting in excess hormone effects, or hypofunction, re-sulting in hormone deficiency. Primary dysfunction iscaused by disease within an endocrine gland. Secondarydysfunction occurs when endocrine tissue is affected bydysfunction of a nonendocrine organ. Functional hyper-function or functional hypofunction results from dis-ease in a nonendocrine tissue or organ.

Pituitary disordersHere are some of the terms used to describe pituitarydysfunction:• Adiposogenital dystrophy is marked by increasedbody fat and underdevelopment of secondary sex charac-teristics in males. This disorder is caused by damage tothe hypothalamus, which causes decreased secretion ofgonadotropic hormones from the anterior pituitary gland.• Diabetes insipidus is caused by deficiency of circulat-ing ADH, or vasopressin. ADH deficiency leads to ex-treme polyuria. Patients can urinate up to 30 L of diluteurine per day because the kidneys can’t concentrateurine.• Hypopituitarism may cause dwarfism as a result ofdecreased levels of GH when it begins in childhood. It’s acomplex syndrome that leads to metabolic problems,sexual immaturity, and growth retardation. These compli-cations are caused by a deficiency of hormones secretedby the anterior pituitary gland.• Panhypopituitarism refers to a generalized conditioncaused by partial or total failure of all six of the pituitary

309DISORDERS

845513.qxd 8/19/08 6:23 PM Page 309

gland’s vital hormones: corticotropin, TSH, LH, FSH, GH,and PRL.

Gonadotrophic hormone excessGonadotrophic hormone excess is a chronic, progres-sive disease marked by excess GH, tissue overgrowth,and hyperpituitarism. It appears in two forms:• Gigantism begins while the bones are still growingand causes proportional overgrowth of all body tissues.• Acromegaly occurs after bone growth is complete,causing bones and organs to thicken. Bones of the face,jaw, and extremities gradually enlarge in a patient withthis condition.

Thyroid disordersTwo types of thyroid dysfunction, hyperthyroidism andhypothyroidism, are described here.

HyperthyroidismHyperthyroidism results from excess thyroid hormone.The most common cause is Graves’ disease, which in-creases T4 production, enlarges the thyroid gland (goi-ter), and causes metabolic changes.

Stormy forecastForms of hyperthyroidism include:• functioning metastatic thyroid carcinoma, a raredisease that causes excess production of thyroid hormone• silent thyroiditis, a self-limiting form of hyperthy-roidism with no inflammatory symptoms• subacute thyroiditis, a viral inflammation of the thy-roid gland, which produces short-term hyperthyroidismassociated with flulike symptoms• thyroid storm, an acute exacerbation of hyperthy-roidism that’s a medical emergency and may lead to car-diac failure• thyrotoxicosis factitia, which results from chronicingestion of thyroid hormone, sometimes by a personwho’s trying to lose weight• toxic adenoma, a small, benign nodule in the thyroidgland that secretes thyroid hormone

310ENDOCRINE SYSTEM

Here’s the long

and short of it—a

malfunctioning

pituitary gland can

lead to dwarfism or

gigantism.

845513.qxd 8/19/08 6:23 PM Page 310

• TSH-secreting pituitary tumor, which causes over-production of thyroid hormone.

HypothyroidismHypothyroidism results from low serum thyroid hor-mone or cellular resistance to thyroid hormone. It’scaused by insufficiency of the hypothalamus, pituitarygland, or thyroid gland. Here are two related terms:• Hashimoto’s thyroiditis is an inflammation of thethyroid gland caused by antibodies to thyroid antigens inthe blood. It causes inflammation and lymphocytic infil-tration of the thyroid, leading to thyroid tissue destruc-tion and hypothyroidism.• Myxedema coma is a life-threatening complication ofhypothyroidism marked by depressed respirations, de-creased cardiac output, and hypotension.

Parathyroid disordersHere’s a list of parathyroid disorders:• Hypoparathyroidism is caused by PTH deficiency ordecreased effectiveness of PTH on target tissues. Be-cause PTH regulates calcium balance, PTH deficiencycauses hypocalcemia (low blood levels of calcium),which leads to neuromuscular symptoms, such as pares-thesia (tingling of the extremities) and tetany (musclerigidity).• Hyperparathyroidism, overactivity of one or more ofthe parathyroid glands and production of excess PTH,promotes bone resorption, which leads to hypercal-cemia. Hypophosphatemia results from increased kid-ney excretion of phosphate. With primary hyperpara-thyroidism, the glands enlarge. In secondary hyper-parathyroidism, the glands produce excessive PTH tocompensate for low calcium levels in the blood caused bysome other abnormality.

Pancreatic disordersThese diseases are associated with the pancreas:• Diabetes mellitus is a chronic insulin deficiency orresistance to insulin by the cells. This form of diabetescauses problems with carbohydrate, protein, and fat me-

311DISORDERS

I think I may be

in trouble.

Hyperparathyroidism

promotes bone

resorption, which

leads to

hypercalcemia.

845513.qxd 8/19/08 6:23 PM Page 311

tabolism. Diabetes mellitus is classified as type 1 (insulin-dependent) or type 2 (non-insulin-dependent). Type 2 dia-betes is the more prevalent form. (See Distinguishingmellitus from insipidus.)• Gestational diabetes is a form of diabetes mellitusthat occurs during pregnancy. Usually, the patient’s con-dition returns to normal after delivery, but she may havean increased risk of developing type 2 diabetes later inlife.

When diabetes gets complicatedA number of complications can occur with diabetes:• Diabetic ketoacidosis is a life-threatening form ofmetabolic acidosis that can arise as a complication of un-controlled diabetes mellitus. Due to a lack of available in-sulin, accumulation of ketone bodies leads to urinary lossof water, potassium, ammonium, and sodium, resulting inhypovolemia, electrolyte imbalances, an extremely highblood glucose level and, commonly, coma.• Hyperosmolar hyperglycemic nonketotic syn-drome (HHNS) is a complication of diabetes mellitus inwhich the level of blood glucose is increased but, be-cause some insulin is present, ketosis doesn’t occur.Coma results when the high concentration of blood glu-cose causes dehydration of brain tissues.• Hypoglycemia is characterized by an abnormally lowblood glucose level. This condition occurs when glucoseis utilized too rapidly, when the rate of glucose release

312ENDOCRINE SYSTEM

Gestational

diabetes is a

form of diabetes

mellitus that

occurs during

pregnancy.

Diabetes mellitus and diabetes insipidus are two distinct dis-eases with similar symptoms, including especially profuse urineexcretion. The word mellitus derives from the Latin word forhoney — diabetes mellitus refers to the sweet smell of a pa-tient’s urine due to excess amounts of glucose. Diabetes in-sipidus produces no such sweetness and is therefore called in-

sipidus, meaning bland.


Distinguishing mellitus frominsipidus

845513.qxd 8/19/08 6:23 PM Page 312

falls behind demand, or when excess insulin enters thebloodstream.

Adrenal disordersHere are names of important adrenal gland disorders:• Addisonian crisis, an acute adrenal crisis, occurswhen the body’s stores of glucocorticoids and mineralo-corticoids are exhausted, leading to hypotension, hypo-glycemia, electrolyte imbalances, cardiac arrhythmiasand, ultimately, death.• Adrenal hyperfunction, also called Cushing’s syn-drome, results from excessive levels of adrenocorticalhormones, especially cortisol. This condition can becaused by hypersecretion of corticotropin by the pitu-itary gland, an corticotropin-secreting tumor of anotherorgan, or the use of glucocorticoid medications.• Adrenal hypofunction, also called Addison’s dis-ease, is the most common sign of adrenal insufficiency,seen when 90% of the gland is destroyed. In this autoim-mune process, circulating antibodies react against adren-al tissue, leading to decreased secretion of androgens,glucocorticoids, and mineralocorticoids. (See Addisonand Cushing.)• Hyperaldosteronism results when the adrenal cortexsecretes excess amounts of aldosterone. It can be a pri-mary disease of the adrenal cortex or a response to otherdisorders. Excessive aldosterone in the bloodstreamprompts the kidneys to reabsorb too much sodium andwater, excreting too much potassium. The fluid retention

313DISORDERS

Addison’s disease is named after the British doctor Thomas Ad-dison (1793–1860), who described this form of adrenal insuffi-ciency in 1849. Harvey Cushing (1869–1939), an American physi-ologist, was the first to note the changes in body appearance—development of fat deposits on the face, neck, and trunk andpurple striae (streaks) on the skin—associated with pituitary tu-mors (Cushing’s syndrome).


Addison and Cushing

845513.qxd 8/19/08 6:23 PM Page 313

and hypokalemia caused by this disorder lead to hyper-tension, decreased hematocrit, muscle weakness, tetany,excess thirst, and many other symptoms.• Pheochromocytoma refers to a vascular tumor of thechromaffin tissue found in the adrenal medulla. This condi-tion is characterized by secretion of epinephrine and nor-epinephrine, causing hypertension associated with attacksof palpitations, nausea, headache, dyspnea, anxiety, pallor,and profuse sweating. (See Focus on pheochromocytoma.)

Treatments

Treatments for endocrine disorders include surgery, radi-ation therapy, and drug therapy.

SurgerySurgeries to correct diseases affecting the endocrine sys-tems are described here:• Adrenalectomy is a resection or removal of one orboth adrenal glands.• Hypophysectomy is the surgical removal of the pitu-itary gland. In a procedure called transsphenoidal hy-pophysectomy, the gland is removed by entering the in-ner aspect of the upper lip through the sphenoid sinus.

314ENDOCRINE SYSTEM

Pheochromocytoma is a vascular tumor of the chromaffin tissuefound in the adrenal medulla. To better understand pheochromo-cytoma, break down the word: • pheo- means dusky• -chromo- means color• -cyt- refers to cell• -oma is a suffix that means tumor.

Thus, pheochromocytoma is a tumor of the dusky-coloredcells of the adrenal glands.


Focus on pheochromocytoma

845513.qxd 8/19/08 6:23 PM Page 314

• Pancreatectomy is removal of the pancreas. This pro-cedure is performed only after more conservative treat-ment measures have failed.• Parathyroidectomy is the surgical removal of one ormore of the four parathyroid glands. It’s used to treat hy-perparathyroidism. The number of glands removed de-pends on the underlying cause of the excessive hormonesecretion.• A subtotal thyroidectomy is surgical removal of aportion of the thyroid gland.• Total bilateral adrenalectomy, excision of bothadrenal glands, eliminates the body’s reserve ofcorticosteroids (which are synthesized in the adrenalcortex). Adrenalectomy is performed only when treat-ment of the pituitary gland is impossible.• Total parathyroidectomy is removal of all of theparathyroid glands. In such cases, the patient requireslifelong treatment for hypoparathyroidism.• In total thyroidectomy, the entire thyroid gland is re-moved.

Radiation therapyThere are two types of radiation treatment for endocrinedisorders:• 131I administration uses an isotope of iodine to treathyperthyroidism or thyroid cancer. It shrinks functioningthyroid tissue, decreases levels of thyroid hormone in thebody, and destroys malignant cells.• Pituitary radiation controls the growth of a pituitarytumor or relieves its signs and symptoms.

Drug therapyHere are some common drug therapies for en-docrine disorders:• Corticosteroids and hormone replace-ments are administered to combat hormone de-ficiencies.• Insulin or oral antidiabetic agents may beadministered to control glucose levels.

315TREATMENTS

Out I go.

Pancreatectomy isremoval of the

pancreas, which is

done only after

more conservative

measures have

failed.

Get ready for

some fun and

games!

845513.qxd 8/19/08 6:23 PM Page 315

316ENDOCRINE SYSTEM

Vocabulary builders

Across

2. Enlarged spleen6. Also known as the pituitary

gland

7. Inner portion of the adrenalgland10. Stimulates the adrenal cortex

13. Stimulates the ejection ofbreast milk into the mammaryducts15. Excessive hunger16. Proportional overgrowth ofbody tissues

Down

1. Condition characterized by ab-normally low blood glucose level2. Promotes the growth of bonyand soft tissues3. Hormone that decreases bloodglucose levels4. Hormones produced by theadrenal cortex5. Influences secretion of thyroidhormone

8. Excessive thirst (a sign of dia-betes mellitus)9. Organ that lies along the posteri-or surface of the abdominal wallbehind the stomach11. Hormone that increases bloodglucose levels12. Abbreviation for radioim-

munoassay

14. Gland located below the ster-num


1 2

3

4 5

6

7

8 9

10 11

12

13

14

15

16

At a crossroadsCompleting this crossword puzzle will help stimulate yourexcretion of correct endocrine system terms. Good luck!

845513.qxd 8/19/08 6:23 PM Page 316


Match gameAs with many medical terms, some endocrine terms go by more than one name. Matcheach hormone or organ below with its alternate name.

Clues

1. Pituitary gland ____

2. Growth hormone ____

3. Antidiuretic hormone ____

4. Mammotropin ____

Choices

A. Somatotropin

B. Prolactin

C. Hypophysis

D. Vasopressin

Finish lineFill in the blanks below with the appropriate treatment or surgical intervention.

1. Removal of the entire thyroid gland is known as ______ ______.

2. ______ is a surgery that’s used to remove the pancreas after more conservativetreatment measures have failed.

3. The resection or removal of one or both adrenal glands is known as ______.

4. ______ ______ controls the growth of a pituitary tumor or relieves its signs andsymptoms.

5. When only a portion of the thyroid gland is surgically removed it’s called a ____________.

6. The surgical removal of the pituitary gland is known as ______.

I’m frazzled. Is

it my hormones

or these

questions?


845513.qxd 8/19/08 6:23 PM Page 317

318ENDOCRINE SYSTEM

1. C; 2. A; 3. D; 4. B

Match game

1. Total thyroidectomy; 2. Pancreatectomy; 3. Adrenalectomy;4. Pituitary radiation; 5. Subtotal thyroidectomy; 6. Hypophysectomy

Finish line

At a crossroads

Answers

1H

2S P L E N O M E G A L Y

Y O3

I

P M4C

5T N

O A O6H Y P O P H Y S I S

G T R Y U

L O T R7M E D U L L A

Y T I O8P I

9P

10C O R T I C O T R O P I N N

11G A

E O O R L12R L N

M P I13O X Y T O C I N U C

I I D P D A C R

A N S I I14T A E

N15P O L Y P H A G I A

S Y O S16G I G A N T I S M M N

A U

S

I’ve heard

the next

chapter is a

real eye

opener.

845513.qxd 8/19/08 6:23 PM Page 318

Blood and lymphatic structure andfunction

The circulatory system consists of blood, which ispumped through blood vessels by the heart, and lymphat-ic fluid, which moves through lymph channels and tissuespassively. Blood and the lymphatic system are intercon-nected. Lymph fluid passes into the veins through thelymphatic and thoracic ducts. (See Pronouncing keyblood and lymphatic system terms, page 320.)

Fancy fluidsThe liquid portion of blood is called plasma. In the lym-phatic system, the liquid portion is called lymph fluid.Both fluid types are high in water content, but they differin their distribution of fats and proteins.

14

Health assessmentBlood and the lymphatic system

Just the facts


♦ terminology related to the structure and function ofthe blood and the lymphatic system

♦ terminology needed for physical examination of theblood and lympathic system

♦ tests that help diagnose blood and lymphatic sys-tem disorders

♦ common blood and lymphatic system disorders andtheir treatments.

Did you know that

the average person

has 5 to 6 L of

circulating blood,

which makes up about

5% to 7% of the

body’s weight?

845514.qxd 8/19/08 6:30 PM Page 319

Shared traitsBlood and the lymphatic system share some similar func-tions. For example, both collect and transport vital sub-stances and both are involved in protecting and healingthe body.

They're special, so specialBlood and the lymphatic system each contain specializedcells suspended in fluid. Most of these cells are producedby the bone marrow. The specialized cells help the bodyprotect itself, working as part of the immune system.

CellsCells specific to the blood and lymphatic system includeerythrocytes (also known as red blood cells [RBCs]),leukocytes (also known as white blood cells [WBCs]),thrombocytes (also known as platelets), and pluripo-tential stem cells.

320BLOOD AND THE LYMPHATIC SYSTEM

Here’s a list of key terms related to blood and the lymphatic sys-tem, along with the correct ways to pronounce them.


Pronouncing key blood andlymphatic system terms

Hemolysis

Hemorrhage

Immunoelectrophoresis

Lymphadenopathy

Phagocytosis

Splenomegaly

Thymus

Trabeculae

HEE-MAHL-EH-SIS

HEM-EH-REHJ

IM-YOU-NOH-EE-LEK-TROH-FOH-REE-SIS

LIM-FAD-UH-NOP-UH-THEE

FAG-OH-SEYE-TOH-SIS

SPLEE-NO-MEG-UH-LEE

THEYE-MUHS

TRAH-BEK-YOU-LEE

845514.qxd 8/19/08 6:30 PM Page 320

Seeing redRBCs account for 99% of the circulating elements inblood and transport oxygen and carbon dioxide. The av-erage RBC lives about 120 days and then is phagocy-tized (destroyed and digested) by cells in the spleen andliver. Iron from the hemoglobin on the RBCs is recoveredand recycled.

The ABCs of WBCsWBCs are active in the immune system. The varioustypes of WBCs are classified into two categories accord-ing to how they appear when stained and viewed under amicroscope:• granular leukocytes (having a grainlike appearance)• nongranular leukocytes (having few or no granularparticles).

Although some WBCs constantly circulate, others re-main in the tissues of the lymph system, bone marrow,spleen, and other organs.

First respondersPlatelets are small cell fragments that circulate in bloodand respond to injuries by starting the clotting processand providing hemostasis (stoppage of bleeding).

To stem cells and beyond!Pluripotential stem cells are located in the bone marrow.They develop into immune system and blood cellsthrough a process called hematopoiesis. (See Breakingdown blood formation.)

Some stem cells destined to produce immune sys-tem cells serve as sources of lymphocytes (a type ofWBC), whereas others develop into phagocytes (cellsthat engulf and digest microorganisms and cellular de-bris). Those that become lymphocytes are differentiat-ed to become either B cells (which mature in the bonemarrow) or T cells (which travel to the thymus andmature there).

B cells and T cells are distributed throughout thelymphoid organs, especially the lymph nodes andspleen.

321BLOOD AND LYMPHATIC STRUCTURE AND FUNCTION

Breaking downblood formation

Hematopoiesis mayseem like a difficult wordat first glance, but breakit down and the difficultydisappears.

In Greek, hematos isthe word for blood andpoiesis means form-ation. Together they formthe word for bloodformation—hemato-

poiesis.


I’m a pluripotential

stem cell. That means

I have the potential to

take many (pluri-)

forms.

845514.qxd 8/19/08 6:30 PM Page 321

Basic T-cell trainingIn the thymus (a lymph structure located inthe mediastinum), T cells undergo a processcalled T-cell education, in which the cells are“trained” to recognize other cells from thesame body (self cells) and distinguish themfrom all other cells (nonself cells).

Organs and tissues of blood and the lymphatic system

Bone marrowBone marrow is found in the cranial bones, vertebrae,ribs, pelvis, sternum, and femurs. It's the site of aprocess called erythropoiesis, in which erythropoi-etin (a potent hormone secreted by the kidneys) stimu-lates the bone marrow to produce RBCs. Platelets alsooriginate from stem cells in the bone marrow.

The term lymphoid is used to refer to organs and tis-sues of the lymphatic system because they’re all involvedin some way in the growth, development, and dissemina-tion of lymphocytes. (See How nymph became lymph.)

Lymph nodesThe small, kidney-shaped lymph nodes contain lymphat-ic tissue and are located along a network of lymphaticchannels. They release lymphocytes, the primary cells ofthe immune system, and help remove and destroy antigenscirculating in the blood and lymphatic vessels. Each lymphnode is surrounded by a fibrous capsule that extends tra-beculae (bands of connective tissue) into the node.

Function is an emphatic issue for lymphatic tissueWhen lymph fluid enters the node, it’s filtered through si-nuses before draining into the single exit vessel. The fil-tration process removes bacteria and other foreign bod-ies or particles, including malignant cells.

Another function of lymph nodes is phagocytosis,the destruction of invading cells or particles. Lymphatictissue is also the site of final maturation for lymphocytesthat migrate from the bone marrow.


How nymphbecame lymph

Lymph fluid is a clear,transparent liquid that’sfound in the lymphatic

vessels, which take theirname from this sub-stance. In Greek, nymph

was the name for a god-dess of lower rank usu-ally associated with ariver or lake. In turn, theGreeks applied the termto young women, “pureas a virgin river,” of mar-riageable age. Latin bor-rowed the term, but then mutated to an l and itbecame applied to a fluidthought to be as pureand clear as the nymphsof long ago.


I’m a T cell and

this is my friend,

a B cell. We’re

both lymphocytes,

but I grew up in

the thymus…

…and I grew

up in the bone

marrow—

that’s how we

got our names.

845514.qxd 8/19/08 6:30 PM Page 322

Location, location, locationLymph nodes are classified according to their locations,including:• axillary—underarm and upper chest• cervical—neck• inguinal—groin area• popliteal—behind the knee• submandibular— floor of the mouth and lower jaw.

Lymphatic fluidLymphatic fluid (also lymph fluid or lymph) is a trans-parent, usually slightly yellow liquid found within the lym-phatic vessels. It’s collected from all parts of the body andreturned to the blood after filtration in the lymph nodes.

Lymphatic vesselsLymphatic vessels intertwine with blood vessels anddistribute lymphatic fluid throughout the body. They re-move proteins and water from the interstitial spaces andreturn them to the bloodstream.

Lymphatic vessels located in the small intestine arecalled lacteals. They absorb fats and other nutrients,producing a milky lymph fluid called chyle (from theGreek word chylos, or juice).

SpleenThe spleen is a lymphoid organ located in the left upperquadrant of the abdomen beneath the diaphragm. Thelargest structure of the lymphatic system, the spleen initi-ates an immune response, filters and removes bacteriaand other foreign substances from the bloodstream, de-stroys worn-out blood cells (hemolysis), and serves as ablood reservoir. (See History of spleen, page 324.)

Accessory lymphoid organs and tissuesThe tonsils, adenoids, appendix, thymus, and Peyer’s patch-es remove foreign debris in much the same way lymphnodes do. They’re located in food and air passages—areaswhere microbial access is more likely to occur.


The word

lacteal probably

reminds you of

the word lactate,which means to

produce milk.

Lacteals produce

a “milky” lymph

fluid.

845514.qxd 8/19/08 6:30 PM Page 323

ImmunityImmunity is the body’s capacity to resist invading organ-isms and toxins, thereby preventing tissue and organdamage. The immune system’s cells and organs are de-signed to recognize, respond to, and eliminate foreignsubstances, including bacteria, viruses, and parasites.The immune system also preserves the body’s internal en-vironment by scavenging dead or damaged cells and bypatrolling antigens.

Getting specificAll foreign substances elicit the same response in generalhost defenses. In contrast, particular microorganisms ormolecules activate specific immune responses and initial-ly can involve specialized sets of immune cells. Such spe-cific responses, classified as either humoral immunity orcell-mediated immunity, are produced by lymphocytes (Bcells and T cells).

Humoral immunityIn humoral immunity, an invading antigen causes Bcells to divide and differentiate into plasma cells. Eachplasma cell, in turn, produces and secretes large amountsof antibodies (immunoglobulin molecules that interactwith a specific antigen) into the bloodstream. Antibodiesdestroy bacteria and viruses, thereby preventing themfrom entering host cells.

Five major classes of immunoglobulin exist:• Immunoglobulin (Ig) G makes up 80% of plasma anti-bodies. It appears in all body fluids and is the major an-tibacterial and antiviral antibody.• IgM is the first immunoglobulin produced during animmune response. It’s too large to easily cross membranebarriers and is usually present only in the vascular sys-tem.• IgA is found mainly in body secretions, such as saliva,sweat, tears, mucus, bile, and colostrum. It defendsagainst pathogens on body surfaces, especially those thatenter the respiratory and GI tracts.• IgD is present in plasma and is easily broken down. It’sthe predominant antibody on the surface of B cells and ismainly an antigen receptor.


History ofspleen

Since ancient times, theword spleen has beenused to designate thelargest lymphatic organ.The word probably firstappeared in its modernform between 1250 and1300, having been de-rived from the Latin wordsplen. The origins of theword go back even fur-ther, to the ancient San-skrit plihan.

Spleen: Cheerful or

gloomy?

The spleen was consid-ered to be the seat ofvarious emotions or at-tributes. Some were pos-itive, linking the spleenwith cheerfulness,courage, and spirit. Atother times, the spleenwas thought to be thesite of negative attribut-es, such as a bad temperand a spiteful or gloomynature.


845514.qxd 8/19/08 6:30 PM Page 324

• IgE is the antibody involved in immediate hypersensi-tivity reactions (or allergic reactions) that develop withinminutes of exposure to an antigen. IgE stimulates the re-lease of mast cell granules, which contain histamine andheparin.

Another part of humoral immunity, the complementsystem, is a major mediator of the inflammatory re-sponse. It consists of 20 proteins circulating as functional-ly inactive molecules. In most cases, an antigen-antibodyreaction is necessary for the complement system to acti-vate to destroy invading cells.

Cell-mediated immunityIn cell-mediated immunity, T cells respond directly toantigens (foreign substances such as bacteria or toxinsthat induce antibody formation). This response involvesdestruction of target cells—such as virus-infected cellsand cancer cells—through the secretion of lymphokines(lymph proteins). Organ rejection is an example of cell-mediated immunity.

Acquired immunityThe body readily develops long-term immunity to specificantigens, including pollen, dust, mold, and invading or-ganisms. There are four types of acquired immunity:

Natural, active immunity occurs when the immunesystem responds to a harmful agent and develops long-term immunity. This type of immunity is the most effec-tive and longest lasting. For example, people develop im-munity to measles after having the disease once.

Natural, passive immunity is the transfer of anti-bodies from a mother to a fetus (through the placenta) orto a breast-fed infant. This type of transmission providestemporary, partial immunity.

Artificial, active immunity is obtained by vaccina-tion with weakened or dead infectious agents introducedinto the body to alert the immune system.

Artificial, passive immunity is provided by sub-stances that offer immediate but temporary immunity,such as antibiotics, gamma globulin, and interferon.


I’m a natural,

thanks to

passive

immunity!

845514.qxd 8/19/08 6:30 PM Page 325


The following conditions may be encountered when per-forming a physical examination of blood and the lym-phatic system:• Angioedema is a subcutaneous and dermal eruptionthat produces deep, large, raised sections of skin (usuallyon the hands, feet, lips, genitals, and eyelids) and diffuseswelling of the subcutaneous tissue.• Butterfly rash is a classic sign of systemic lupus ery-thematosus. Lesions appear on the cheeks and bridge ofthe nose, creating a characteristic butterfly-shaped pattern.• Chills (also called rigors) are extreme, involuntarymuscle contractions with characteristic paroxysms of vi-olent shivering and tooth chattering.• Cyanosis is a blue to purple color of the skin, nail bed,and lips due to a lack of oxygen.• Ecchymosis is another name for a bruise.• Epistaxis is a profuse nosebleed.• Hematochezia is the passing of bloody stools.• Hemoptysis is bleeding from the lungs or bronchialtubes.• Hemorrhage refers to uncontrolled bleeding.• Lymphadenopathy is enlarged lymph nodes.• Lymphangioma is a benign tumor caused by congeni-tal malformation of the lymphatic system.• Pruritus is also known as itching.• Splenomegaly is an enlarged spleen.• Thrombosis is the formation of a blood clot inside ablood vessel.• Urticaria is a skin condition that’s more commonlyknown as hives.

Diagnostic tests

Most tests use a combination of techniques to evaluatethe body’s immune response and break down the individ-ual components of blood and the lymphatic system.


Thrombosisis the formation

of a blood clot

inside a blood

vessel.

845514.qxd 8/19/08 6:30 PM Page 326

Laboratory testsHere are some common laboratory tests:• ABO blood typing classifies blood according to thepresence of major antigens A and B on RBC surfaces andaccording to serum antibodies anti-A and anti-B. ABOblood typing is required before transfusion to prevent alethal reaction.• Complete blood count (CBC) measures the numberof blood elements in a blood sample.• Crossmatching is an antibody detection test that es-tablishes the compatibility of a donor’s and recipient’sblood.• A direct antiglobulin test (direct Coombs’ test)demonstrates the presence of antibodies (such as anti-bodies to the Rh factor) or complement on circulatingRBCs.• Enzyme-linked immunosorbent assay (ELISA)identifies antibodies to bacteria, viruses, deoxyribonu-cleic acid, allergens, and substances such as immuno-globulins.• Erythrocyte sedimentation rate (ESR) is the de-gree of erythrocyte settling in a blood sample during aspecified period.• Hematocrit measures the percentage of RBCs in ablood sample.• Hemoglobin (Hb) is the measure of the amount of he-moglobin in a volume of blood.• Human leukocyte antigen test (HLA) identifies agroup of antigens that are present on the surfaces of allnucleated cells but most easily detected on lymphocytes.These antigens are essential to immunity and determinethe degree of histocompatibility between transplant re-cipients and donors.• Immunoelectrophoresis identifies immunoglobulinsin a serum sample. It evaluates the effectiveness of radia-tion therapy or chemotherapy and detects hypogamma-globulinemias (abnormally low levels of gamma globu-lins causing increased susceptibility to infection).• The platelet count indicates the number of plateletsin a microliter of blood.• Prothrombin time (PT) is commonly used to evalu-ate clotting in patients receiving oral anticoagulanttherapy.

327DIAGNOSTIC TESTS

845514.qxd 8/19/08 6:30 PM Page 327

• Rh typing classifies blood by the presence or absenceof the Rho(D) antigen on the surface of RBCs. In this test,a patient’s RBCs are mixed with serum containing anti-Rho(D) antibodies and are observed for clamping to-gether of antigen-bearing particles of similar size in aso-lution.• Shilling test determines a patient’s ability to absorbvitamin B12, which is necessary for erythropoiesis.• WBC count, also called a leukocyte count, is part of acomplete blood count. It indicates the number of WBCsin a microliter of whole blood.• The WBC differential evaluates the type, number, andcondition of WBCs present in the blood. WBCs are classi-fied as one of five major types of leukocytes—neutro-phils, eosinophils, basophils, lymphocytes, and mono-cytes—and the percentage of each type is determined inthis test.• Western blot test detects the presence of specific vi-ral proteins.

Patch and scratch allergy testsPatch and scratch allergy tests evaluate the immune sys-tem’s ability to respond to known allergens, which are ap-plied to hairless areas of the patient’s body.

Patch workIn patch testing, a dilute solution of each allergen isplaced directly on the skin and covered with gauze. In 48to 72 hours, the appearance of redness, vesicles, itching,or swelling shows a positive reaction.

Scratching the surfaceScratch tests introduce allergens into a scratched areaon the patient’s skin with a special tool or needle. Testsites are examined 30 to 40 minutes later and comparedwith a control site; redness, itching, or swelling are con-sidered positive reactions.

Under your skinIntradermal skin tests evaluate the patient’s immunesystem by injecting recall antigens (antigens to whichthe patient may have been previously sensitized) into the


A patch test

shows results in 2 to

3 days. A scratch

test works more

quickly; results show

in 30 to 40 minutes.

845514.qxd 8/19/08 6:30 PM Page 328

superficial skin layer with a needle and syringe or a ster-ile four-pronged lancet.

Bone marrow aspirationIn a bone marrow aspiration or biopsy, a small amountof bone marrow is removed and the blood elements andtheir precursors are evaluated. The specimen is alsochecked for the presence of abnormal or malignant cells.

Disorders

Bone marrow cells reproduce rapidly and are vulnerableto genetic or environmental conditions that influence cellfunction or the body’s ability to make cells. For example,heredity may cause genetic defects in the type or amountof cells or the ability of cells to function. Environmentalfactors, such as nutrition, medications, radiation, andtoxins, may affect bone marrow's ability to make normalcells. Additionally, the complex processes involved inhost defense and immune response may malfunction.When the body’s defenses are exaggerated, misdirected,absent, or depressed, a hypersensitivity disorder, autoim-munity, or immunodeficiency may result.

This section provides terminology associated withblood and lymphatic system disorders.

Blood disordersBlood disorders may be quantitative or qualitative. Quan-titative blood disorders involve abnormalities in the num-ber of cells. These disorders may result from the bonemarrow producing too few or too many cells or fromprocesses that destroy cells. Quantitative blood disordersinclude certain types of anemias, such as these:• Aplastic anemia results from injury to the stem cellsin the bone marrow, which causes decreased productionof RBCs, WBCs, and platelets.• Pernicious anemia is caused by a deficiency in the ab-sorption of vitamin B12 (folic acid) due to a lack of hydro-chloric acid in the stomach. (Vitamin B12 is essential forthe production of RBCs.)

329DISORDERS

845514.qxd 8/19/08 6:30 PM Page 329

• Myeloproliferative disorders occur when the bonemarrow produces too many cells, although an excess ofRBCs is rare.• Erythroblastosis fetalis, also known as Rh factorincompatibility between a mother and her fetus, occurswhen antibodies in the mother’s blood destroy the fetus’sRBCs, resulting in fetal anemia. Intrauterine transfusionscan save about 40% of the fetuses affected.• Posthemorrhagic anemia is the result of acute orchronic blood loss.

Quality countsQualitative blood disorders involve abnormalitieswithin the cells or plasma components. Here are someexamples:• Sickle cell anemia is a hereditary disease in whichRBCs are abnormally “sickle” shaped and can’t easilytravel through the blood vessels.• Thalassemia is a hereditary type of anemia in whichHb isn’t produced properly.

Blood-clotting disordersBlood-clotting, or hemorrhagic disorders result fromcellular abnormalities in the clotting cycle or problemswith clotting factors in the plasma. They may be heredi-tary or acquired.

Here's a list of some blood-clotting disorders:• Disseminated intravascular coagulation (DIC) is alife-threatening disease in which the patient may suffersevere hemorrhage. It occurs when other conditionscause the circulating clotting factors and platelets to de-plete, leaving the patient prone to bleeding.• Factor V Leiden mutation is a relatively common in-herited mutation in the factor V gene that may cause thedevelopment of inappropriate blood clots and, in youngpeople, an increased risk of stroke.• Hemophilias are a group of hereditary bleeding disor-ders in which there are deficiencies in the clotting factorsnecessary for coagulation.• Inherited thrombophilias are diseases in which ab-normal clotting factor traits are inherited, causing clotsto form in the blood vessels inappropriately.• Idiopathic thrombocytopenic purpura is caused byan abnormal immune response that destroys platelets. It


Blood

disorders may

result from

abnormalities in

the quantity or

quality of cells.

845514.qxd 8/19/08 6:30 PM Page 330

may be acute and follow a viral infection. Patients usuallyrecover without treatment.• Thrombocytopenias are the most common of theblood-clotting disorders and result from deficiencies inthe number of circulating platelets.

Hypersensitivity disordersAn exaggerated or inappropriate immune response maylead to various hypersensitivity disorders, such as asth-ma, allergic rhinitis, anaphylaxis, atopic dermatitis, latexallergy, and blood transfusion reactions.

AsthmaAsthma is a chronic, reactive airway disorder leading toepisodes of airway obstruction with bronchospasms, in-creased mucus secretion, and mucosal swelling. (SeeHow do I [pant] say asthma?)

Take a deep breathHere are a few types of asthma:• Acute asthma is an attack that can begin either dra-matically with severe symptoms or slowly with gradualsymptoms.• Extrinsic asthma results from sensitivity to pollen,animal dander, mold, or other sensitizing substances.• Intrinsic asthma is diagnosed when no extrinsic aller-gen can be identified.• Status asthmaticus is a persistent, intractable asthmaattack that can lead to acute respiratory failure.

Allergic rhinitisAllergic rhinitis is a reaction to airborne (inhaled) aller-gens. The resulting runny nose, itching, nasal obstruction,and congestion can be seasonal, as in hay fever, or year-round, as in perennial allergic rhinitis.

AnaphylaxisAnaphylaxis is a dramatic, acute reaction marked by thesudden onset of rapidly progressive hives and respiratorydistress. It can be a life-threatening situation if treatmentisn’t initiated immediately.

331DISORDERS

Hyperreactivityand hypersensitivityshare a prefix. Hyper-

comes from Greek

and means in excess

of. These are

disorders that cause

an excessive reaction

or sensitivity in the

immune system.

How do I (pant)say asthma?

Asthma derives fromGreek and means gasp-ing or panting. Thegrouping of consonantsin its middle makes itlook more difficult to pro-nounce than it actuallyis. The th is silent, mak-ing the word easily pro-nounceable: AZ-MAH.


845514.qxd 8/19/08 6:31 PM Page 331

Atopic dermatitisAtopic dermatitis is a chronic skin disorder character-ized by superficial skin inflammation and intense itching.

Latex allergyLatex allergy is a hypersensitivity reaction to productsthat contain natural latex, which is derived from the sapof a rubber tree. Hypersensitivity reactions to latex rangefrom local dermatitis to life-threatening anaphylactic re-action.

Blood transfusion reactionsMediated by immune or nonimmune factors, a transfusionreaction happens during or after the administration ofblood components. Symptoms can be mild (fever andchills) or severe (acute renal failure or complete vascularcollapse and death), depending on the amount of bloodtransfused, the type of reaction, and the patient’s generalhealth.

Poorly made matchesHemolytic reactions follow transfusions of mismatchedblood. When this occurs, RBCs clump together and breakdown, leading to kidney damage.

Less worrisomeAllergic reactions to transfused blood are fairly com-mon and only occasionally serious. Patients may experi-ence transient hives, itching, chills, and fever. Symptomsresolve quickly when the transfusion is stopped.

More commonFebrile nonhemolytic reactions, the most commontype of reaction, apparently develop when antibodies inthe patient’s plasma attack antigens on lymphocytes,granulocytes, or plasma cells of the transfused blood.

Autoimmune disordersAutoimmune disorders occur when a misdirected immuneresponse causes the body’s defenses to become self-destructive. Here are some types of autoimmune disorders:• Ankylosing spondylitis is a chronic, usually progres-sive, inflammatory disease that primarily affects the


Hypersensitivity

reactions to latex

range from local

dermatitis to life-

threatening

anaphylactic

reaction.

845514.qxd 8/19/08 6:31 PM Page 332

sacroiliac, apophyseal, and costovertebral joints and ad-jacent soft tissue.• Rheumatoid arthritis is a chronic, systemic inflam-matory disease that primarily attacks peripheral jointsand surrounding muscles, tendons, ligaments, and bloodvessels.• Scleroderma is a diffuse connective tissue diseasecharacterized by fibrotic, degenerative, and occasionallyinflammatory changes in the skin, blood vessels, synovialmembranes, skeletal muscles, and internal organs.• Sjögren’s syndrome, the second most commonrheumatoid disorder, is marked by decreased secretionsfrom the lacrimal and salivary glands.• Systemic lupus erythematosus (SLE) is a chronicinflammatory disorder of the connective tissue. It affectsmultiple organ systems, is characterized by remissionsand exacerbations, and can be fatal.• Vasculitis includes a broad spectrum of disorders char-acterized by inflammation and necrosis of blood vessels.

Immunodeficiency disordersIn immunodeficiency, the immune system is absent or de-pressed, resulting in increased susceptibility to infection.

Opportunity knocksAlso known as AIDS, acquired immunodeficiencysyndrome causes progressive damage to the body’s im-mune response and gradual destruction of cells—includ-ing T cells. The retrovirus human immunodeficiencyvirus (HIV) causes AIDS.

Major immunity missingDiGeorge syndrome is a congenital aplasia or hypopla-sia of the thymus that’s caused by a missing gene on chro-mosome 22. This abnormality leads to a deficiency of Tlymphocytes and compromises cell-mediated immunity.

Chemo complicationIatrogenic immunodeficiency is a deficiency in the im-mune response that occurs as a complication ofchemotherapy and other medical treatment.

333DISORDERS

Lupus is Latin for

wolf. It was first used

as a medical term

because disorders

such as systemiclupus erythematosuswere thought to devour

the body like a

hungry wolf.

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Treatments

Various methods are used to combat disorders of bloodand the lymphatic system, including drug therapy, radia-tion therapy, surgery, and bone marrow transplantation.

Drug therapyHere’s a list of drugs commonly used to treat blood andlymphatic system disorders:• Anticoagulants are drugs given to inhibit blood clot-ting.• Antilymphocyte serum, or antithymocyte globulin,is an anti-T-cell antibody that reduces the number andfunction of T cells. This suppresses cell-mediated immu-nity. The drug is used to prevent rejection of tissue graftsor transplants.• Corticosteroids are adrenocortical hormones widelyused to treat immune disorders because of their anti-inflammatory and immunosuppressant effects. Thesedrugs stabilize the vascular membrane, blocking tissueinfiltration by neutrophils and monocytes and thus in-hibiting inflammation.• Cytotoxic drugs kill cells while they’re replicating.However, most cytotoxic drugs aren’t selective and,therefore, interfere with all rapidly growing cells. As a re-sult, they reduce the number of lymphocytes as well asphagocytes.• Cyclosporine is an immunosuppressant drug that se-lectively suppresses T-helper cells, resulting in depressedimmunity. It’s used to prevent organ rejection in kidney,liver, bone marrow, and heart transplants.• Thrombolytic drugs are given to break apart bloodclots.• Iron supplements may be given to patients with ane-mia after the cause of the anemia is determined.

Radiation therapyRadiation therapy is the use of a radioactive substanceto treat a disease. Radiation therapy of all major lymphnode areas—known as total nodal radiation—is usedto treat certain disorders, such as Hodgkin’s disease.


Drugs are

one way to treat

blood and

lymphatic system

disorders.

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SurgerySurgeries for lymphatic and immune system disorders in-clude the removal of a lymph node, a lymph vessel, thespleen, or the thymus:• Lymphadenectomy is surgical removal of a lymph node.• Lymphangiectomy is surgical removal of a lymph vessel.• Splenectomy, or removal of the spleen, causes an in-creased risk of infection, especially from such bacteria asStreptococcus pneumoniae.• Thymectomy is surgical removal of the thymus.

Bone marrow transplantationBone marrow transplantation begins with the collec-tion of marrow cells from a donor. The cells are thentransferred to an immunosuppressed patient. There arefour types of bone marrow transplant:• Allogeneic transplant uses bone marrow from acompatible donor, usually a sibling.• Autologous transplant uses marrow tissue that’s har-vested from the patient before he receives chemotherapyand radiation therapy, or while he’s in remission, and isfrozen for later use.• Stem cell transplant involves the transfusion of stemcells, which can develop into RBCs, WBCs, and platelets.Stem cells are typically donated by the patient beforechemotherapy.• Syngeneic transplant refers to the transplantation ofmarrow between identical twins.

Blood transfusionsA blood transfusion is a procedure in which blood orblood products are introduced into the patient’s blood-stream. Here are two types of blood transfusions:• Autologous transfusion involves a patient donatingblood so it can be stored for his own later use.• Homologous transfusion is when blood is voluntarilydonated by one person and given to a compatible recipi-ent.

335TREATMENTS

Memoryjogger

To rememberthe differ-

ence between an “al-logeneic” transplantand “autologous”transplant, visualizethe “gene” in allo-geneic and think “thegene pool that’s yourfamily.” For autolo-gous, remember that“auto” = self, meaningyou can donate bloodto yourself.

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Across

3. The largest structure of the lym-phatic system4. Term indicating location behindthe knee6. Term used to refer to immunesystem organs and tissues10. Eponym for the second mostcommon autoimmune rheumatoiddisorder11. Process by which stem cellsdevelop into blood cells or immunesystem cells

12. Immunodeficiency introducedby a medical treatment13. Response activated by mi-croorganisms15. The type of transplant of mar-row between identical twins17. Tests that introduce allergensto the skin using a special tool,with results examined 30 to 40 min-utes later18. A chronic, reactive airway dis-order

Down

1. The “S” in ESR

2. A group of 20 protein com-pounds that activate to destroy in-vading cells5. Exaggerated systemic reactionof the immune system7. Masses of lymphatic tissue lo-cated at the back of the mouth andthroat8. Bands of connective tissue9. Reactions that follow transfusionof mismatched blood

12. The body’s capacity to resist in-vading organisms and toxins14. Lymphatic vessel located in thesmall intestine16. Acronym for test that identifiesantibodies to bacteria, among oth-ers


1 2

3 4

5 6 7

8

9 10

11

12

13 14

15 16

17

18

Vocabulary builders

At a crossroadsCompleting this crossword puzzle will help you ward off anattack by incorrect blood and lymphatic system terms. Goodluck!

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1. ____ ____ ____ ____ ____ ____ ____ ____

2. ____ ____ ____ ____ ____ ____ ____ ____

3. ____ ____ ____ ____ ____ ____ ____ ____ ____

____ ____ ____ ____

4. ____ ____ ____ ____ ____

5. ____ ____ ____ ____ ____ ____ ____ ____ ____ ____


Talking in circlesUse the clues below to fill in the blanks with the appropriate word. Then unscramblethe circled letters to find the answer to the question posed at left.


Match gameThe long-term immunity the body develops to specific antigens is called acquiredimmunity. Match the following types of acquired immunity to their definitions.

Clues

1. Natural, passive ____

2. Artificial, active ____

3. Natural, active ____

4. Artificial, passive ____

Choices

A. When the immune system responds to aharmful agent and develops long-term resis-tance

B. The transfer of antibodies from a mother toher fetus or breast-fed infant, providing tempo-rary, partial resistance

C. Obtained by vaccination with weakened ordead infectious agents

D. Provided by substances that give immediatebut temporary immunity, such as antibiotics,gamma globulin, and interferon

Which

specialized cell

originates as a

stem cell in the

bone marrow and

helps provide the

body with

immunity?

1. A protein produced in response to specific antigens2. A lymph node found in the underarm or upper chest 3. The classic sign of SLE 4. A milky lymph fluid produced by lacteals 5. A type of transplant that uses bone marrow from a compatible donor

845514.qxd 8/19/08 6:31 PM Page 337


At a crossroads

Answers

I sense the

next chapter will

be of great

interest!

1S

2C

3S P L E E N

4P O P L I T E A L

D M5A I

6L Y M P H O I D

7T

N M L8T O

A9H E E

10S J O G R E N

P E N M A S11H E M A T O P O I E S I S B I

Y O A N E L

L L T12

I A T R O G E N I C S

A Y I M U

X T O13

I M M U N E L14

L

I I N U A A

S C N15S Y N G

16E N E I C

I L T17S C R A T C H I E

Y18A S T H M A

A L

1. B; 2. C; 3. A; 4. D

Match game

1. Antibody; 2. Axillary; 3. Butterfly rash; 4. Chyle; 5. AllogeneicSolution to puzzle—B cell

Talking in circles

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Sensory structure and function

Sensory stimulation allows the body to interact with theenvironment. The brain receives stimulation from thesense organs—the eyes, the ears, and the gustatory(taste) and olfactory (smell) organs located in the noseand mouth. (See Pronouncing key sensory systemterms, page 340.)

VisionThe eye is the sensory organ of sight and transmits visualimages to the brain for interpretation. The eyeball occu-pies the bony orbit, a skull cavity formed by bones ofthe face. The term optic, as well as the prefixes oculo-and ophthalmo-, refers to the eye. (See Eye terms, page340.)

15

Health assessmentSensory system

Just the facts


♦ terminology related to the structure and function ofthe sensory system

♦ terminology needed for physical examination of thesensory system

♦ tests that help diagnose common sensory systemdisorders

♦ common sensory system disorders and their treat-ments.

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The outer eyeSix cranial nerves serve the eye, the ocular muscles, andthe lacrimal apparatus. The coordinated action of sixmuscles controls eye movement. Extraocular structures—the eyelids, conjunctivae, and lacrimal apparatus—pro-tect and lubricate the eye.

Eye protectorsThe eyelids, also called palpebrae, are loose folds ofskin covering the front of the eye. They provide protec-tion from foreign bodies, regulate the entrance of light,and distribute tears over the eye by blinking. The lid mar-gins contain hair follicles, which in turn contain eyelash-es (cilia) and sebaceous glands.

Conjunctivae are transparent mucous membranesthat protect the eye from foreign bodies. The palpebralconjunctiva lines the eyelids and appears shiny andpinkish red. The bulbar conjunctiva joins the palpebralportion and covers the sclera up to the limbus. A small,fleshy elevation called the caruncle sits at the nasal as-pect of the conjunctivae.

These crying eyesThe lacrimal apparatus lubricates and protects the eyewith tears produced by lacrimal glands. After washing

340SENSORY SYSTEM

Here’s a list of key terms related to the sensory system, alongwith the correct ways to pronounce them.


Pronouncing key sensory systemterms

Eye terms

Many eye terms are de-rived from Greek or Latinroots. Recognizing theseroots will help you quick-ly understand many eyeterms.

Eye know Greek

The term optic meanspertaining to the eye orsight and derives fromthe Greek word of thesame meaning, optikos.

The optic disk, therefore,is a round area withinthe eye. The opt- of “op-tic” is used as a prefix toform other terms pertain-ing to the eye, such asoptometry, the scienceof treating the humaneye.

Ophthalmo-, from theGreek word for eye, oph-

thalmos, also forms “eyewords” such as ophthal-

moscope, an instrumentused for examining theinner eye.

Eye know Latin

The root oculo-, from theLatin word for eye, ocu-

lus, is also used to formmany terms that refer tothe eye; for example, in-

traocular, which meanswithin the eyeball—as inintraocular structures.


Auricle

Choanae

Cilia

Eustachian

Optesthesia

Tinnitus

AW-RIH-KUHL

KOH-AY-NEE

SILL-EE-AH

YOU-STAY-SHEE-UHN

AHP-TEHS-THEE-ZYUH

TIHN-IH-TEHS or TIH-NEYE-TEHS

845515.qxd 8/19/08 7:19 PM Page 340

across the eyeball, tears drain through the punctum, atiny opening at the junction of the upper and lower eye-lids. From there, tears flow through lacrimal canals intothe lacrimal sac. They then drain through the naso-lacrimal duct and into the nose.

The inner eyeThe sclera is the white part of the eyeball. Composed offibrous tissue and fine elastic fibers, it’s covered by theconjunctiva and bathed by tears from the lacrimal glands.

The light of the eyeThe cornea is a smooth, transparent portion of the eye-ball through which light enters the eye. It bulges slightlywith a domelike protrusion and lacks blood vessels. Thecornea is very sensitive to touch.

Looking straight in the eyeThe iris is a circular disk in the center of the eye with theability to contract. The anterior and posterior chambersof the iris are filled with a clear watery fluid called aque-ous humor. This fluid drains through the trabecular mesh-work into Schlemm’s canal (a sinus at the junction of thecornea and the iris). Intraocular pressure (IOP) is thebalance of pressure between secretion and removal offluid.

Focus on thisThe pupil, or central opening of the iris, is black in color.By expanding and contracting, it regulates the amount oflight admitted to the lens. Enclosed in an elastic capsuledirectly behind the iris, the lens acts like a camera lens,refracting and focusing light onto the retina.

The reception areaThe retina receives visual stimuli and sends them to thebrain.

Optical equipmentThe optic disk is a well-defined, round, yellow to pinkdisk within the nasal portion of the retina. It allows theoptic nerve to enter the retina at the nerve head.

Photoreceptors called rods and cones, named fortheir shape, are the visual receptors of the retina and areresponsible for vision. The rods, located toward the out-

341SENSORY STRUCTURE AND FUNCTION

Lacrimal comes

from the Latin

word for a

teardrop, lacrima.

The lens of a

camera takes its

name from the lens in

our eyes. They

perform the same

function: refracting

and focusing light.

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side of the retina, respond to low-intensity light andshades of gray. The cones are concentrated in the centerand respond to bright light and color.

It’s all clear hereLocated to the side of the optic disk is the macula, whichis slightly darker than the rest of the retina. A region inthe macula called the fovea centralis is the site of clear-est vision, where cones are most concentrated and norods are found. Because the fovea centralis contains theheaviest concentration of cones, it’s a main receiver of vi-sion and color.

Focusing on convergenceThe process called accommodation allows the eyes tofocus on light rays that are close or far away. The eye-balls are converged (move together) by muscles at-tached to the eyeball and the bones of the orbit.

HearingThe ear is a sensory organ that enables hearing andmaintains equilibrium. It’s conveniently divided into theexternal, middle, and inner ear.

The external earThe auricle, or pinna (pinna means wing), is the carti-lage-based outer part of the ear. The external auditorymeatus (opening) is the short passage leading into theear. Earwax, also called cerumen, lines this canal, whichends at the tympanic membrane.

Drum roll, please…The tympanic membrane separates the external earfrom the middle ear. Also called the eardrum, it picks upsound waves and transmits them to the auditory nerve inthe brain.

The middle earThe middle ear is located in a small, air-filled cavity inthe temporal bone called the tympanic cavity. It lies be-tween the tympanic membrane and the inner ear andcommunicates with the throat by way of the eustachiantube, which keeps air pressure equal on both sides of the

342SENSORY SYSTEM

Why is the

tympanic membranecalled the eardrum?

For starters, the

term comes from the

Greek word for kettle

drum, tympanon, and

most importantly, it

acts like a drum when

struck by sound

vibrations.

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eardrum. The tympanic membrane is so sensitive to airpressure that rapid changes in altitude can produce pain,feelings of pressure, and ringing in the ears (tinnitus).

A hammer, anvil, and stirrupThe middle ear contains three small bones named fortheir shapes—the malleus (hammer), incus (anvil), andstapes (stirrup). Connected by joints, their mechanicalactivity transmits sound waves to the inner ear. The threebones together are called the auditory ossicles (bones).The stapes sits in an opening called the oval window(fenestra ovalis), through which sound vibrationstravel to the inner ear.

The inner earA bony labyrinth and a membrane-covered labyrinthcombine to form the inner ear. It consists of thevestibule, a small space at the beginning of a canal,and two systems of canals, the cochlea and the semi-circular.

Ear-y canalsSensory tissue in the semicircular canals maintains thebody’s sense of position and equilibrium. The cochlea(which means spiral or shell-shaped) contains threecanals separated from one another by thin membranes:• The vestibular canal connects with the oval windowthat leads to the middle ear.• The tympanic canal is connected to the round win-dow, which also leads to the middle ear. Both of thesecanals are bony and contain perilymph fluid.• The cochlear canal is membranous and filled with en-dolymph fluid.

Located in the cochlear canal is the organ of Corti,a spiral-shaped membrane made up of cells with pro-jecting hairs that transmit sound to the cochlear branchof the acoustic nerve.

Listen upFor hearing to occur, sound waves travel through theear by two pathways:

Air conduction occurs when sound waves travelin the air through the external and middle ear to the in-ner ear.

343SENSORY STRUCTURE AND FUNCTION

For me to hear

what Polly is saying,

the sound of her voice

has to travel to my

inner ear through airconduction, bone

conduction, or both!

Otoliths are made up

of tiny particles of

calcium carbonate and

a gelatinous mixture

found in the vestibule of

the inner ear. They help

with maintaining

balance and equilibrium.

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Bone conduction occurs when sound waves travelthrough bone to the inner ear.

SmellThe sensory organ for smell, the nose, also warms, fil-ters, and humidifies inhaled air. The word elementsnaso- and rhino- and the term olfactory refer to thenose, including the external parts and internal cavities.

The nose knowsThe olfactory epithelium within the nose is the actualorgan of smell, perceiving odors when its cells are stimu-lated. Olfactory receptors are located in a narrow shelfformed by the superior nasal concha, the upper part ofthe septum, and—bordering the nostrils on the lowerpart of each side—the winglike alae. Smells received bythe olfactory epithelium are transmitted to the olfactorybulb and continue from there to olfactory centers in thebrain. (See Not that kind of factory.)

Nosing around the inside of the noseThe upper third of the nose consists of bone, and the low-er two-thirds is made of cartilage. Cilia, tiny hairs thatfilter inhaled air, line the vestibule, the area inside thenostrils. The nasal septum separates the nostrils.Grooves called meatuses separate the three curved,bony structures called turbinates (superior, middle,and inferior), which aid breathing by warming, filtering,and humidifying inhaled air. Posterior air passagesknown as choanae lead to the oropharynx (throat).

And right out in front of your noseThe upper, narrow end of the nose is called the root. Thebridge extends from the root to the tip. The externalnares are the two outer openings, separated by the nasalseptum. The alae flare out from either side of the nares.

TouchThe skin is the organ of touch, able to receive sensationsof pressure, heat, cold, and pain. Touch, or light pressureperception, occurs when dendrites (free sensory nerveendings in the skin) are stimulated.

344SENSORY SYSTEM

The nose can

identify about 10,000

odors—but all result

from combinations of

the six basic odors:

flowery, fruity, spicy,

resinous, burned, and

putrid. Phew!

Not that kind offactory

When studying thesense of smell and thenose, the term olfactory

comes up often, as in ol-

factory epithelium, theactual organ of smell. Al-though the term olfacto-

ry suggests a smell fac-tory, the term actuallyderives from the Latinword for smell, olfactus.


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A light touchMerkel’s disks are tactile corpuscles in the epidermisthat relay light touch and superficial pressure. Meissner’scorpuscles (in the corium below the epidermis), receivelight pressure sensation. Heavy pressure is transmitted byPacini’s corpuscles, layered sensory nerve tissues in theskin’s subcutaneous layer.

Touchy to temperature changesThe skin reacts to temperature changes of even a few de-grees. Although the mechanism is unknown, skin capillar-ies, free nerve endings, and Ruffini’s corpuscles (in thecorium) help send temperature information to the brain.

TasteThe taste buds are the receptors for the taste nervefibers located in the papillae (small projections on thetongue). A few taste buds are found in the mucous mem-branes of the soft palate, the opening from the mouth tothe throat, and the epiglottis. (See A tasteful history.)


This section will provide terms you may need to know forphysical examination of the sensory system.

Examining visionAn ophthalmoscope, which contains a light, a mirrorwith a single hole, and several lenses, is used for examin-ing the interior structures of the eye. This instrument isalso called a funduscope. These terms are used in physi-cal examination of the sense of vision:• anisopia—unequal vision in two eyes• astigmatism—impairment in vision due to an irregu-larity in the curvature of the cornea or lens• blepharospasm—spasms or constant blinking of theeyelid• diplopia—double vision• exophthalmos—unilateral or bilateral bulging or pro-trusion of the eyeballs• floaters—tiny clumps of vitreous gel appearing tofloat in the visual field (see Keeping it simple, page 346.)


A tastefulhistory

The term gustatory per-tains to the sense oftaste and derives fromthe Latin word gustare,

to taste. Another “taste-ful” English word, orrather “distasteful,” thatis derived from thatsame Latin root is dis-

gust, which literallymeans to cause nausea.


In the term

blepharospasm,blepharo comes from

the Greek word

blepharon, which

means eyelid.

845515.qxd 8/19/08 7:19 PM Page 345

• monochromatism—total color blindness• myopia—nearsightedness• nyctalopia—night blindness• optic neuritis—inflammation of the optic nerve• presbyopia—inability to focus on small print due toloss of elasticity of the lens (a normal sign of aging)• ptosis—drooping of the eyelid• strabismus—absence of coordinated eye movement,leading to misalignment of the eyes• uveitis—inflammation of the uvea, including the iris,ciliary body, and choroid.

Examining hearingAn otoscope is a device for examining the ear, includingthe external ear, eardrum, and ossicles. This instrumentincludes a device for insufflation (blowing vapor orpowder into a cavity), a light, and a magnifying glass. Hereare terms involved with physical examination of the ear:• otorrhagia—bleeding from the ear• otorrhea—discharge from the ear• ototoxic—a substance toxic to the eighth cranialnerve or the organs of balance and hearing• tinnitus—ringing in one or both ears• vertigo—a sensation of movement in which the pa-tient feels himself revolving in space or surroundings re-volving about him (may result from inner ear disease).

Examining sense of smellThe following terms are used in the physical examinationof the sense of smell:• anosmia—absence of the sense of smell• dysosmia—a defect in or impairment of the sense ofsmell• hyperosmia—abnormal sensitivity to odors• osmesthesia—inability to perceive and distinguishodors• osmodysphoria—abnormal dislike of certain odors.

Examining sense of tasteThe following terms are used in the physical examinationof the sense of taste:• ageusia—an impaired or absent sense of taste

346SENSORY SYSTEM

Keeping itsimple

Not all medical terms arederived from Greek andLatin and contain manysyllables. Sometimes asimple word best de-scribes a medical phe-nomenon. Take, for ex-ample, the term floaters,

a coined term for the tinyclumps of vitreous gelthat appear to “float” inthe eyes.

The realworld

Memoryjogger

Here’s thenear and far,

so to speak, of twovision examinationterms:

• myopia (nearsight-edness), vision is bet-ter for near ratherthan far objects.

• hyperopia (far-sightedness), visionis better for farrather then near ob-jects.

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• dysgeusia—abnormal or distorted sense of taste• hypergeusia—unusual acuteness of taste• hypogeusia—impaired sense of taste.

Diagnostic tests

Many methods are used to diagnose the origins of sensorydiseases or conditions. Some tests measure an individualcomponent’s level of function in the sensory system, whileothers examine each component for injury. This sectionreviews diagnostic test terms for the sensory system.

Eye testsEye tests can be conducted either under direct evaluationor with radiologic and imaging equipment.

Direct evaluationIn direct evaluation, tests are applied directly to the eyeby the examiner with the aid of various pieces of equip-ment.

Look into the lightRefraction is an examination to determine and correctrefractive eye errors. The ophthalmologist usually per-forms a refraction with a retinoscope. In this test, theexaminer uses the retinoscope to shine a light into thepatient’s eye. The examiner then notes the reflexivemovements of the fundus.

In the spotlightSlit-lamp examination gets its name from the piece ofequipment used, an instrument equipped with a speciallighting system and a binocular microscope that allowsthe examiner to view details of the eye, including the eye-lids, eyelashes, conjunctiva, and cornea.

Eye know IOPTonometry permits indirect measurement of IOP.

Radiologic and imaging studiesRadiologic and imaging equipment can make the innereye visible for closer study.

347DIAGNOSTIC TESTS

Most enlightening!

In refraction, the

examiner uses the

retinoscope to shine a

light into the

patient’s eye. The

examiner then notes

the reflexive

movements of the

fundus.

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Shutter bugFluorescein angiography records the appearance ofblood vessels inside the eye through rapid-sequencephotographs of the fundus. The photographs follow theI.V. injection of sodium fluorescein, a contrast medium.

Sounding it outOcular ultrasonography transmits high-frequencysound waves through the eye and measures their reflec-tion from ocular structures.

Eye of the stormOther eye examinations and terms include:• Orbital computed tomography (CT) reveals abnor-malities that can’t be seen with standard X-rays. The or-bital CT scan is a series of tomograms reconstructed by acomputer and displayed as anatomic slices on a screen.• Orbital radiography examines the orbit (the deep-setcavity housing the eye), lacrimal gland, blood vessels,nerves, muscles, and fat.• A scanning laser ophthalmoscope is a laser deviceused to detect abnormal retinal secretions.

Visual acuity testsA Snellen eye chart is the standard chart usedin eye examinations, containing block lettersof decreasing size read by the patient from adistance.

Visual field tests determine the extent ofthe retin-al area through which the patient canperceive visual stimuli.

Testing the earsWhen performing diagnostic tests on the sense of hear-ing, the examiner generally needs the participation of thepatient. After all, only the individual being tested can tellthe examiner whether he heard something.

First lookOtoscopy is the direct visualization of the external audi-tory canal and the tympanic membrane through an instru-ment called an otoscope.

348SENSORY SYSTEM

845515.qxd 8/19/08 7:19 PM Page 348

Tuning fork testsTuning fork tests such as Weber’s test and the Rinne testare quick screening tools for detecting hearing loss.

Good vibrationsWeber’s test evaluates bone conduction by placing a vi-brating tuning fork on top of the patient’s head at themidline or in the middle of the patient’s forehead. The pa-tient should perceive the sound equally in both ears.

The Rinne test compares bone conduction to airconduction in both ears by placing the base of a vibratingtuning fork on the mastoid process and noting how manyseconds pass before the patient can no longer hear it.

Audiometric testsAudiometric tests are performed by audiologists toconfirm hearing loss. Audiometry is the evaluation ofhearing using an audiometer, a device that measuresperception of tones at various frequencies. (See I hear.)

Reaching the thresholdPure-tone audiometry provides a record of the thresh-olds—the lowest intensity levels—at which a patient canhear a set of test tones through earphones or a bone con-duction (sound) vibrator. The test tones are concentrat-ed at certain frequencies labeled bone conduction thresh-olds and air conduction thresholds. In Békésy audiome-try, a patient pushes a button to indicate that a tone washeard.

Going with the flowAcoustic admittance tests evaluate middle ear func-tion by measuring sound energy’s flow into the ear (ad-mittance) and the opposition to that flow (impedance).Two tests are used to measure admittance:• Tympanometry measures middle ear admittance in re-sponse to air pressure changes in the ear canal.• The acoustic reflex test measures the change in ad-mittance produced by contraction of the stapedius mus-cle as it responds to an intense sound.

ElectrocochleographyElectrocochleography measures the electrical currentgenerated in the inner ear after sound stimulation. The

349DIAGNOSTIC TESTS

I hear

You’re probably familiarwith the word audio. Youown audio equipment(such as a radio) andmaybe even consideryourself an audiophile

(one devoted to high-quality sound equip-ment). But did you knowthat audio is the Latinword for I hear? There-fore, it makes sense thattests that examine yourability to hear are calledaudiometric.


845515.qxd 8/19/08 7:19 PM Page 349

current is measured by an electrode in the externalacoustic canal. (See Isn’t there an abbreviation?)

ElectronystagmographyIn electronystagmography, eye movements in responseto specific stimuli are recorded on graph paper and usedto evaluate the interactions of the vestibular system andthe muscles controlling eye movement in what is knownas the vestibulo-ocular reflex.

Tests for smellThe Proetz test measures the acuity of smell, using dif-ferent concentrations of substances with recognizableodors.

Do you smell something?The lowest concentration at which the patient recognizesan odor is called the olfactory coefficient, or minimalidentifiable odor.

Disorders

The sensory system is a complex system with even morecomplicated components. This section provides terminol-ogy related to disorders of the sensory system.

Eye disordersEye disorders can range from common irritation in andaround the eyes to impaired vision. Various types of eyedisorders are discussed here.

Common inflammations and infections• Blepharitis is a common inflammatory condition ofthe eyelids, lash follicles, and glands of the eyelids, char-acterized by swelling, redness, and crusts of dried mucuson the eyelids.• Conjunctivitis is an inflammation or infection of theconjunctiva, sometimes called pinkeye. (See Is pinkeyepink?)

350SENSORY SYSTEM

Isn’t there anabbreviation?

Generally, tests withlong, hard-to-pronouncenames like electro-

cochleography are re-ferred to by an abbrevia-tion. In this case, maybeECG would be appropri-ate; however, that abbre-viation is for the termelectrocardiogram.

What do you do then?Take a deep breath andsound it out: EH-LECK-TROH-KAWK-LEE-AWG-RAH-FEE.


The Proetz

(pronounced PRHOTS)

test measures the

acuity of smell, using

different

concentrations of

substances with

recognizable odors.

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• Dacryocystitis is a common infection of the lacrimalsac caused by an obstruction (dacryostenosis) of thenasolacrimal duct or by trauma.• Keratitis is an inflammation of the cornea, usuallyconfined to one eye, and it may be acute or chronic, su-perficial or deep.

Other eye disordersOne common cause of vision loss, a cataract is a gradu-ally developing opacity of the lens or lens capsule of theeye.

Here are some other eye disorders:• Corneal abrasion, a scratch on the surface epitheliumof the cornea, is often caused by a foreign body.• Macular degeneration, the atrophy or degenerationof the macular disk, is the most common cause of blind-ness in adults.• Nystagmus is recurring, involuntary eyeball movementthat produces blurred vision and difficulty in focusing.The movement may be horizontal, vertical, rotating, ormixed.

Too much pressureGlaucoma is a group of disorders characterized by anabnormally high IOP, which can damage the optic nerve.Left untreated, it can cause blindness. Glaucoma occursin several forms:• Chronic open-angle glaucoma results from overpro-duction of aqueous humor.• Acute angle-closure glaucoma results from obstruc-tion to the outflow of aqueous humor.• Secondary glaucoma can result from uveitis, trauma,or drugs such as steroids.

Looking to the retinaIn retinal detachment, the retinal layers split andcreate a subretinal space, which fills with fluid (calledsubretinal fluid).

A genetically transmitted disorder, retinitis pigmen-tosa causes progressive destruction of the retinal rodsand leads to eventual blindness.

Noninflammatory retinal disorders, called vascularretinopathies, result from disruption of the eye’s bloodsupply. The two types of this condition are:

351DISORDERS

Is pinkeye pink?

The inflammation causedby pinkeye may strikesome as pink in colorand therefore explain theorigin of its use, but theterm probably derivesfrom the Middle Englishword pinken, whichmeans to prick.

Pinkeye originallywas used to indicatehalf-shut, or what youreye would look like afterit was pricked or poked,and what it may look likeif you’re suffering frompinkeye.


845515.qxd 8/19/08 7:19 PM Page 351

• Hypertensive retinopathy results from prolongedhypertensive disease, which produces retinal vasospasmand consequently damages and narrows the arteriolaropening.• Diabetic retinopathy is retinopathy that results as acomplication of diabetes.

Ear disordersEar disorders can range from common irritation to seri-ous hearing loss.

Hearing lossHearing loss (deafness) results from a dysfunction inthe mechanical or nervous system that disrupts transmis-sion of sound waves. It’s classified as:• conductive loss—interrupted transmission of soundimpulses from the external ear to the junction of thestapes and oval window• mixed hearing loss—combined conductive and sen-sorineural dysfunctions• otosclerosis—slow growth of a spongy bone in theotic capsule, particularly at the oval window (the mostcommon cause of progressive conductive hearing loss)• sensorineural loss—impaired cochlear or acousticnerve function that prevents transmission of sound im-pulses within the inner ear or brain.

The older we getPresbycusis, an effect of aging, results from the loss ofhair cells in the organ of Corti. This disorder causes sen-sorineural hearing loss, usually of high-frequency tones.

Ear disorders without chronic hearinglossHere are some common disorders of the ear thatgenerally have no long-term effect on hearing:• Infectious myringitis is characterized by in-flammation, hemorrhage, and effusion of fluid intothe tissue and at the end of the external ear canaland tympanic membrane.• Labyrinthitis, an inflammation of the labyrinth of theinner ear, frequently causes severe vertigo.

352SENSORY SYSTEM

I said,

“Presbycusiscomes from the

Greek words

presbys, meaning

old man, and

akouein, which

means to hear.”

845515.qxd 8/19/08 7:19 PM Page 352

• Mastoiditis is a bacterial infection and inflammationof the mastoid antrum air cells and is commonly a com-plication of chronic or acute otitis media.• Ménière’s disease, also called endolymphatic hy-drops, is a labyrinthine dysfunction known to cause vio-lent attacks of severe vertigo lasting from 10 minutes toseveral hours.• Otitis externa is an inflammation of the external earcanal, which may be acute or chronic.• Otitis media is an inflammation of the middle ear.

Treatments

Treatment options for sensory system disorders includedrug therapy, surgery and, in some cases, a transplant re-placing a damaged component.

Eye treatmentsDrug therapy is a common treatment for eye disorders.

Drug therapyThe most frequently used drugs include:• Anti-infectives, such as bacitracin and erythromycin,are used to treat infection.• Anti-inflammatory agents, such a dexamethasone,are used to treat inflammatory conditions of the eye.• Artificial tears provide moisture for the eyes when in-sufficient tear production is a problem.• Miotics are agents that cause constriction of the pupil.• Mydriatics are agents that dilate the pupil of the eye.• Ophthalmic anesthetics prepare the eye for proce-dures, such as tonometry, suture removal from thecornea, or removal of foreign bodies.

Eye surgerySurgery may involve the repair, removal, or transplant ofa failing component of the eye. Surgeons often employlaser surgery, using a laser that generates focused, ormonochromatic, light waves; it then magnifies their pow-er by deflecting them off a series of mirrors. The result isa finely focused, high-energy beam.

353TREATMENTS

Ménière’sdisease can cause

violent attacks of

severe vertigo.

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• Cataracts are removed by one of two methods. In in-tracapsular cataract extraction, the entire lens is re-moved, most often with a cryoprobe, a surgical instru-ment that freezes and adheres to the lens, making thelens easier to remove. Extracapsular cataract extrac-tion removes the patient’s anterior capsule, cortex, andnucleus, leaving the posterior capsule intact. This tech-nique uses irrigation and aspiration or phacoemulsifica-tion. Phacoemulsification uses an ultrasonic probe tobreak the lens into minute particles and aspirate them.(See How do I say phacoemulsification?)• Performed by laser or standard surgery, an iridectomyreduces IOP by improving the drainage of aqueous hu-mor. The procedure makes a hole in the iris, creating anopening though which the aqueous humor can flow to by-pass the pupil.• Radial keratotomy is a treatment for myopia (near-sightedness) that involves the creation of small radial in-cisions in the cornea. These incisions flatten the corneaand help properly focus light on the retina.• Sclerectomy is excision of part of the sclera.• Scleral buckling is surgical repair of a detached reti-na, in which indentations of the sclera are made over theretinal tears to promote retinal adherence to the choroid.• Trabeculectomy is a surgical filtering procedure thatremoves part of the trabecular meshwork, allowing aque-ous humor to bypass blocked channels. This procedurecreates a filtering bleb or opening under the conjunctiva.• A microsurgical procedure, vitrectomy removes partor all of the vitreous humor—the transparent gelatinoussubstance that fills the cavity behind the lens. It’s alsoused for removal of foreign bodies and infection withinthe eye.

Restoring clarityIn a corneal transplant, healthy corneal tissue from ahuman donor replaces a damaged part of the cornea. Thetransplant can take one of two forms:

Full-thickness penetrating keratoplasty involvesexcision and replacement of the entire cornea.

Lamellar keratoplasty removes and replaces a su-perficial layer of corneal tissue.

354SENSORY SYSTEM

How do I sayphacoemulsifi-cation?

Phacoemulsification isthe process by whichan ultrasonic devicedisintegrates a cataract.Phakos is the Greek termfor lens, and emulsifica-

tion is the process bywhich something isemulsified or brokendown. This word be-comes easier to pro-nounce when you breakit down phonetically:FACK-OH-EE-MULL-SIH-FIH-KAY-SHUN.


In corneal

transplantation,

corneal tissue from a

human donor replaces

a damaged part of

the cornea.

845515.qxd 8/19/08 7:19 PM Page 354

Lasik surgery (laser-assisted in situ keratomileusis)uses a laser to reshape the cornea and correct vision.

Ear treatmentsTreatments for ear disorders range from drug therapy tosurgical intervention.

Drug therapyThe following drugs are used to treat otic disorders:• Acetic acid, or Domeboro’s Solution, treats earcanal infections (and prevents “swimmer’s ear”).• Anesthetics treat pain from otitis media and assistwith removal of cerumen.• Antibiotics treat external ear canal infection.• Cerumeolytics help remove impacted cerumen.• Corticosteroids, such as hydrocortisone, treat inflam-mation of the external ear canal.

Ear surgerySurgical procedures can either repair or remove a failingcomponent.

Drum repairMyringotomy is a surgical incision into the tympanicmembrane to relieve pain and drain pus or fluid from themiddle ear. Myringoplasty is performed to repair a rup-tured tympanic membrane. The surgeon approximatesthe edges of the membrane or applies a graft taken fromthe temporalis muscle.

Taking off the stirrupsStapedectomy removes all or part of the stapes. A totalstapedectomy involves removal of the entire bone, fol-lowed by insertion of a graft and prosthesis to bridge thegap between the incus and the inner ear.

In a partial stapedectomy, the surgeon removespart of the bone and rebuilds what’s left with a prosthe-sis. Laser stapedectomy, a relatively new technique, iseasier to perform but carries a risk of the laser beam pen-etrating the bone.

355TREATMENTS

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356SENSORY SYSTEM

Across

1. Another name for eyelids

3. Eponym for the spiral-shapedmembrane that transmits sound tothe cochlear branch5. Absence of the sense of smell8. Latin term for teardrop9. Term for earwax10. Number of basic odors11. Free sensory nerve endings

12. Particles of calcium carbonatein the small sacs of the vestibule14. Ringing in the ears15. Organ of touch18. Air passages from the nosethat lead to the throat19. This test evaluates bone con-duction20. The eyeball occupies thebony ___21. The white part of the eyeball

Down

2. Process that allows eyes to fo-cus on light rays that are close orfar away4. Eponym for corpuscles that areinvolved in sending temperatureinformation to the brain

6. Location of taste buds7. Unequal vision in the two eyes13. Name that lends itself to thestandard eye chart16. Test that measures the acuityof smell17. Part of the eye that receives vi-sual stimuli


1 2 3 4

5 6

7 8

9

10

11

12 13

14

15 16

17

18

19

20

21

Vocabulary builders

At a crossroadsCompleting this crossword puzzle will help you come to yoursenses about correct sensory system terms. Good luck!

845515.qxd 8/19/08 7:19 PM Page 356


Finish lineTears protect and lubricate the eye. Lacrimal pertains to tears and comes from theLatin word lacrima, which means tear. Fill in the blanks for the eye structures involvedin tear production.

1. The lacrimal _____ lubricates and protects the eye with tears.

2. The lacrimal _____ produce tears.

3. The lacrimal _____ are where tears flow after draining through the punctum.

4. The lacrimal _____ is where the tears then collect.

5. The ___-lacrimal ___ is where tears drain through into the nose.


Talking in circlesUse the clues below to fill in the blanks with the appropriate word. Then unscramble thecircled letters to find the answer to the question posed at left.

1. ____ ____ ____ ____ ____ ____ ____

2. ____ ____ ____ ____ ____ ____ ____

3. ____ ____ ____ ____ ____ ____ ____ ____

4. ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____

5. ____ ____ ____ ____ ____

6. ____ ____ ____ ____ ____ ____ ____ ____ ____

7. ____ ____ ____ ____ ____ ____ ____

1. Contains three canals within the ear and means shell-shaped2. The standard chart used in eye examinations3. A gradually developing opacity of the lens of the eye4. A surgical incision into the tympanic membrane to relieve pain5. The central opening of the iris, which is black in color6. Means pertaining to the sense of taste7. Disks in the epidermis that relay light touch and superficial pressure

I am one of

three small

bones in the

middle ear that

hammers away

at sound waves.

Which bone am I?

845515.qxd 8/19/08 7:19 PM Page 357

358SENSORY SYSTEM

At a crossroads

Answers

I can sense

without even

looking that

you’ve done a

great job with

this chapter.

1. Apparatus; 2. Glands; 3. Canals; 4. Sac; 5. Naso-, Duct

Finish line

1. Cochlea; 2. Snellen; 3. Cataract;4. Myringotomy; 5. Pupil; 6. Gustatory; 7. Merkel’s

Solution to puzzle—Malleus

Talking in circles

1P

2A L P E B R A E

3C O

4R T I

C U

C F5A N O S M I A

6P F

M7A

8L A C R I M A

9C E R U M E N N P N

O I10S I X I

11D E N D R I T E S L

A12O T O L I T H

13S

14T I N N I T U S P A N

I15S K I N E

16P E

O17R A R L

18C H O A N A E O L

T19W E B E R

20O R B I T T N

N Z21S C L E R A

845515.qxd 8/19/08 7:19 PM Page 358

Pharmacology basics

Pharmacology is the scientific study of the origin, nature,chemistry, effects, and uses of medications. The termpharmacology originated from the Greek root phar-mako, which means medicine. (See Pronouncing keypharmacology terms, page 360.)

Pharmacology contains three main branches:

Pharmacokinetics refers to the absorption, distrib-ution, metabolism, and excretion of a drug in a living or-ganism.

Pharmacodynamics is the study of the biochemicaland physical effects of drugs and the mechanisms of drugactions in living organisms.

Pharmacotherapeutics refers to the use of drugsto prevent and treat diseases.

PharmacokineticsThe term kinetics means movement; therefore, phar-macokinetics refers to a drug’s movement through thebody, including how the drug is:

16

Health assessmentClinical pharmacology

Just the facts


♦ terminology related to the fundamentals of clinicalpharmacology

♦ terminology associated with drug administration

♦ medications that affect each body system.

There’s a lot

to know when it

comes to

pharmacology.

845516.qxd 8/19/08 6:53 PM Page 359

• absorbed• distributed• metabolized• excreted.

AbsorptionThe process of drug absorption covers the progress of adrug from the time it’s administered, through the time itpasses to the tissues, until it becomes available for use bythe body. On a cellular level, drugs are primarily absorbedthrough passive or active transport.

No energy requiredPassive transport requires no cellular energy becausethe drug moves from an area of higher concentration toone of lower concentration. It occurs when small mole-cules diffuse across membranes. Diffusion (movement

360CLINICAL PHARMACOLOGY

Here’s a list of key pharmacology terms, along with the correctways to pronounce them.


Pronouncing key pharmacologyterms

Antiemetics

Bioavailability

Catecholamines

Iatrogenic effects

Lipodystrophy

Palliative therapy

Parasympathomimetic

Pharmacodynamics

Pharmacogenetics

Pharmacokinetics

Pharmacotherapeutics

AN-TEE-EH-MET-IKS

BEYE-OH-EH-VAYL-EH-BIHL-IH-TEE

KAT-UH-KOH-LAH-MEENZ

EYE-AT-ROH-JEN-IK EH-FEKS

LIHP-OH-DIHS-TROH-FEE

PAL-EE-AY-TIV THER-UH-PEE

PAR-UH-SIM-PUH-THOH-MI-MEH-TIK

FAR-MAH-KOH-DEYE-NAM-IKS

FAR-MAH-KOH-JEH-NEHT-IKS

FAR-MAH-KOH-KUH-NET-IKS

FAR-MAH-KOH-THER-UH-PYOU-TIKS

In passive

transport, a drug

moves from an area of

higher concentration

to one of lower

concentration.

845516.qxd 8/19/08 6:53 PM Page 360

from a higher concentration to a lower concentration)stops when drug concentration on both sides of the mem-brane equalizes.

Energy requiredActive transport requires cellular energy to move thedrug from an area of lower concentration to one of high-er concentration. Active transport is used to absorb elec-trolytes, such as sodium and potassium.

DistributionDrug distribution is the process by which a drug is de-livered to the tissues and fluids of the body. Distributionof an absorbed drug within the body depends on bloodflow, solubility, and protein binding.

Go with the flowAfter a drug reaches the bloodstream, its distribution inthe body depends on blood flow. The drug is quickly dis-tributed to organs with a large supply of blood, such asthe heart, liver, and kidneys.

Drug crossingThe ability of a drug to cross a cell membrane dependson whether the drug is water soluble or lipid soluble.Lipid-soluble drugs (those capable of dissolving in fat)easily cross through cell membranes, while water-soluble drugs (those capable of dissolving in water)can’t.

Ties that bindAs a drug travels through the body, it comes in contactwith proteins such as the plasma protein albumin. Thedrug can either remain free or bind to the protein. Theportion of a drug that’s protein bound is inactive andcan’t produce a therapeutic effect. Only the free (or un-bound) portion remains active.

MetabolismDrug metabolism, also known as biotransformation,refers to the body’s ability to change a drug from itsdosage form to a more water-soluble form that can laterbe excreted.

361PHARMACOLOGY BASICS

Active transport

requires energy.

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ExcretionDrug excretion refers to the elimination of a drug fromthe body. Most drugs are excreted by the kidneys andleave the body through urine. However, drugs can also beexcreted through the lungs, exocrine glands (sweat, sali-vary, or mammary glands), skin, and intestinal tract.

Half and halfThe half-life of a drug refers to the time it takes for halfof the drug to be eliminated by the body. Knowing howlong a drug remains in the body helps determine how fre-quently a drug should be administered.

Onset, peak, and durationIn addition to absorption, distribution, metabolism, andexcretion, three other factors play important roles in adrug’s pharmacokinetics:• onset of action• peak concentration• duration of action.

Lights, camera…action!Onset of action refers to the time interval that startswhen the drug is administered and ends when the thera-peutic effect actually begins. Rate of onset varies depend-ing on the route of administration and other pharmacoki-netic properties.

Peak performanceAs the body absorbs more of a drug, blood concentrationlevels of that drug rise. The peak concentration level isreached when the absorption rate equals the eliminationrate.

Total effectThe duration of action is the total length of time thedrug produces its therapeutic effect.

PharmacodynamicsPharmacodynamics is the study of drug mechanismsthat produce biochemical or physiologic changes in thebody. Interaction at the cellular level represents drug ac-


The half-life of a

drug refers to the

time it takes for

half of the drug to

be eliminated by

the body.

Pharmacodynamicsis the study of drug

mechanisms that

produce biochemical

or physiologic

changes in the body.

845516.qxd 8/19/08 6:53 PM Page 362

tion. The response resulting from this drug action is re-ferred to as the drug effect.

That’s stimulatingMany drugs work by stimulating or blocking drug recep-tors (a specialized location on a cell membrane or insidea cell). A drug that’s attracted to a receptor displays anaffinity—or attraction—for that receptor. When a drugdisplays an affinity for a receptor and stimulates it, thedrug acts as an agonist. The drug’s ability to initiate a re-sponse after binding with the receptor is referred to asintrinsic activity.

Response busterIf a drug has an affinity for a receptor but displays no in-trinsic activity (in other words, it doesn’t stimulate the re-ceptor), it’s called an antagonist. The antagonist pre-vents a response from occurring.

On-site competitionAntagonists can be competitive or noncompetitive. Acompetitive antagonist competes with the agonist forreceptor sites. Because this type of receptor binds re-versibly to the receptor site, increased doses of an ago-nist can overcome the antagonist’s effects. A noncom-petitive antagonist binds to receptor sites and blocksthe effects of the agonist.

Any one will doIf a drug acts on a variety of receptors, it’s said to be non-selective and can cause multiple and widespread effects.Some receptors are further classified by their specific ef-fects. For example, beta receptors typically produce in-creased heart rate and bronchial relaxation as well asother systemic effects.

It’s got the powerDrug potency refers to the relative amount of a drug re-quired to produce a desired response. Drug potency isalso used to compare two drugs.

Safety marginMost drugs produce a range of multiple effects. The rela-tionship between a drug’s desired therapeutic effect andits adverse effect is called the drug’s therapeutic index.

363PHARMACOLOGY BASICS

Memoryjogger

Here’s a tipfor remem-

bering the differencebetween agonist andantagonist: Think,“Agonists are a go,”meaning that theygive the go-ahead fora drug to stimulatea receptor.

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PharmacotherapeuticsPharmacotherapeutics is the use of drugs to treat dis-ease. When choosing a drug to treat a particular condi-tion, health care providers consider the drug’s effective-ness along with other factors, such as the type and dura-tion of therapy the patient will receive.

Therapy, not always the sameThe type of therapy a patient receives depends on theseverity, urgency, and prognosis of the patient’s condi-tion. A patient may receive:• acute therapy, which is used for those who are symp-tomatically ill and require therapy to correct an underly-ing condition• empiric therapy, which is based on practical experi-ence rather than on pure scientific data• maintenance therapy, which is used to treat chronicconditions that can’t be cured• supplemental or replacement therapy, in order toreplenish or substitute missing substances, such as en-zymes or hormones, in the body• supportive therapy, which doesn’t effec-tively treat the cause of the disease but main-tains other threatened body systems until apatient’s condition improves or resolves• palliative therapy, which is used to treatend-stage or terminal diseases to make thepatient as comfortable as possible.

Different reactionsCertain drugs have a tendency to create drug toleranceand drug dependence. Drug tolerance occurs when apatient shows a decreased response to a particular drugover time. The patient then requires larger doses of thatdrug to produce the same response.

Drug tolerance differs from drug dependence, inwhich a patient displays a physical or psychological needfor the drug. Physical dependence produces withdrawalsymptoms when the drug is stopped, while psychologi-cal dependence causes drug-seeking behaviors.


In drugdependence, a

patient displays

physical or

psychological

need for the

drug.

Drugtolerance

occurs when a

patient shows

a decreased

response to a

particular drug

over time.

845516.qxd 8/19/08 6:53 PM Page 364

Drug interactions

Drug interactions can occur between drugs or betweendrugs and foods. Interactions may impede the results of alaboratory test or produce physical or chemical incom-patibilities. The risk of drug interactions increases in rela-tion to the amount of drugs a patient receives. Potentialdrug interactions include:• additive effects• synergistic effects• antagonistic effects.

Two drugs are better than oneAn additive effect can occur when two drugs with simi-lar actions are administered to a patient. The effects areequivalent to the sum of the effects of either drug admin-istered alone in higher doses.

TeamworkA synergistic effect, also called potentiation, occurswhen two drugs that produce the same effect are giventogether and one drug potentiates (enhances the effectof) the other drug. The combined effect is greater than ei-ther drug can produce when taken alone—for example,the effect produced by taking fentanyl (Sublimaze) andmidazolam (Versed) concomitantly.

Duking it outAn antagonistic effect occurs when the combined re-sponse of two drugs is less than the response producedby either drug alone.

Adverse drug reactionsAn adverse drug reaction (also called a side effect oradverse effect) is a harmful, undesirable response to adrug. Adverse reactions can range from mild ones thatdisappear when the drug is discontinued to debilitatingdiseases that become chronic. Adverse drug reactions areclassified as dose-related or patient sensitivity–related.Dose-related reactions include:• secondary effects• hypersusceptibility• overdose• iatrogenic effects.

365DRUG INTERACTIONS

Drugs can

interact with

other drugs or

with food.

845516.qxd 8/19/08 6:53 PM Page 365

Special effectsIn addition to its major therapeutic effect, a drug typical-ly produces additional secondary effects that are eitherbeneficial or adverse. For example, morphine used to re-lieve pain may cause respiratory depression as an unde-sirable secondary effect. Diphenhydramine used as an an-tihistamine may produce the adverse effect of drowsi-ness; therefore, it’s sometimes prescribed as a sleep aid.

Hyped-up actionEven when the correct therapeutic dose is determined, apatient may experience an excessive therapeutic re-sponse called hypersusceptibility. Hypersusceptibilitytypically results from altered pharmacokinetics leadingto higher-than-expected blood concentration levels.

Over the topAn overdose occurs when an excessive dose of a drug istaken either intentionally or by accident. The result is anexaggerated response (or toxic reaction) to the drugthat causes transient changes or more serious reactions,such as cardiovascular collapse, respiratory depression,or death.

Simon saysSome adverse reactions, known as iatrogenic effects,can mimic pathologic disorders. For example, propra-nolol can induce asthma.

Too sensitivePatient sensitivity–related reactions aren’t as common asdose-related reactions. Sensitivity-related reactions resultfrom a patient’s unusual and extreme sensitivity to adrug. These adverse reactions arise from a unique tissueresponse rather than from an exaggerated pharmacologicaction. Extreme patient sensitivity can occur as a drug al-lergy.

A drug allergy occurs when a patient’s immune sys-tem identifies a drug, a drug metabolite, or a drug conta-minant as a dangerous foreign substance that must beneutralized or destroyed. Previous exposure to the drugor to one with a similar chemical characteristic sensitizesthe patient’s immune system, and subsequent exposurecauses an allergic reaction (hypersensitivity) to occur.


An overdoseoccurs when an

excessive dose of a

drug is taken

either intentionally

or by accident, So

don’t abuse me!

845516.qxd 8/19/08 6:53 PM Page 366

Silent but deadlyThe allergic reaction can vary in intensity from an imme-diate life-threatening anaphylactic reaction (a dramat-ic, acute reaction marked by sudden onset of rapidly pro-gressive hives and respiratory distress) to a mild rash anditching. (See What’s behind an anaphylactic reaction.)

Drug administration

Because prescribing and administering drugs is a criticalresponsibility for health care providers, it’s important tounderstand the terminology associated with drug admin-istration.

Drug ordersIn an outpatient setting, a doctor or health care providerwho’s licensed to prescribe drugs writes an order on aspecial pad and gives it directly to the patient. This isknown as a prescription.

Drug orders in the inpatient setting differ. The follow-ing drug orders are used in inpatient settings:• Standard written orders are written by the healthcare provider and apply indefinitely until another order iswritten to discontinue or alter the first one.• Single orders are orders written for a medicationthat’s given only once.• Stat orders are written for medications that must beadministered immediately to treat an urgent patient prob-lem.• Prescribers write p.r.n. orders for drugs that are to begiven as needed. (See As needed.)• Standing orders, also known as protocol orders, es-tablish guidelines for treating a particular disease or setof symptoms.• Verbal orders are medication orders that are givenorally in urgent situations.• Telephone orders are verbal orders prescribed overthe telephone. This type of drug order is usually only giv-en in urgent situations.

367DRUG ADMINISTRATION

What’s behindan anaphylacticreaction

An anaphylactic reactionis characterized by asudden onset of progres-sive hives and respirato-ry distress in response toa drug. Ana- comes fromthe Greek words an-,

meaning not, and phy-

laxis, meaning protec-tion.


As needed

The abbreviation p.r.n. isderived from the Latinphrase pro re nata,

meaning as the occa-sion arises. Prescriberswrite p.r.n. orders formedications that are tobe given when needed.


845516.qxd 8/19/08 6:53 PM Page 367

Drug formsDrugs are manufactured in many different forms, such assolids, liquids, suppositories, and inhalants. Other drugforms include sprays, which are used with several admin-istration routes; creams, lotions, and patches, which areadministered topically; and lozenges, which are used totreat local effects.

Solidifying solidsSolid drug forms include capsules and tablets. Capsulesare hard or soft gelatin shells that contain the drug in apowder, in sustained-release beads, or in a liquid form.

A tablet is a drug that’s been compressed toform a certain shape. Some tablets are uncoated,while others differ in composition:• Enteric-coated tablets have a thin coatingthat allows the tablet to pass through the stomachand disintegrate or dissolve in the small intestine,where the drug is absorbed.• Osmotic pump tablets release the drugthrough a single tiny hole in the tablet.• Wax matrix tablets distribute the drug through ahoneycomb-like material made of wax.

Liquefying liquidsLiquid medications are usually given orally or parenteral-ly. Orally administered liquids contain the drug mixedwith some type of fluid and are classified as:• syrups—drugs mixed in a sugar-water solution• suspensions—finely divided drug particles suspendedin a suitable liquid medium• tinctures—hydroalcoholic drug solutions• elixirs—hydroalcoholic solutions that contain glyc-erin, sorbitol, or other sweeteners.

Packaging parenteralsParenteral is a term that literally means outside the in-testines. Drugs given parenterally are administered out-side the GI tract and are available in three package styles:• vials—bottles sealed with a rubber diaphragm thatcontain a single dose or several doses• ampules—glass containers with a thin neck that’s typi-cally scored so it can be snapped off easily


A tablet is a

drug that’s been

compressed into a

certain shape.

Tablets come in

different forms.

845516.qxd 8/19/08 6:53 PM Page 368

• prefilled system—a single dose of a drug contained ina plastic bag or a prefilled syringe.

Supposing suppositoriesSuppositories deliver medications in a solid base thatwill melt at body temperature. They can be administeredrectally or vaginally.

Inhaling inhalantsInhalants are drugs that are administered in powderedor liquid form using the respiratory route. Inhalants areabsorbed by the rich supply of capillaries in the lungs.

Routes of administrationThe GI tract provides a fairly safe (but relatively slow-acting) site for drug absorption. When a drug is adminis-tered using the GI tract, it’s called enteral administra-tion. A drug administered by any other route is referredto as parenteral administration.

Enteral administrationOral, sublingual, buccal, and rectal preparations are ad-ministered by the GI tract:• Drugs administered by the oral route are placed in thepatient’s mouth and swallowed. Tablets, capsules, liquids,and lozenges are administered this way.• The sublingual route involves placing an uncoatedtablet under the tongue, where it disintegrates and dis-solves.• A drug administered by the buccal route is placed be-tween the cheek and gum, where it disintegrates and dis-solves.• Suppositories and enemas (a solution introduced intothe rectum or colon) are administered by the rectal route.This route is commonly used when the oral route is pro-hibited, such as in a patient with nausea or vomiting.

Parenteral administrationDrugs may be administered parenterally through fourtypes of direct injections:• intradermal—injected directly into the skin• subcutaneous—injected into the subcutaneous tissue


There are many

ways to take

drugs. Inhalants

are administered

via the respiratory

system.

845516.qxd 8/19/08 6:53 PM Page 369

• intramuscular—injected directly into a muscle• intravenous—injected into a vein.

Under my skin…Intradermal (I.D.) injections are used for skin testssuch as tuberculin. The ventral (anterior portion) fore-arm is the site of choice for I.D. injections.

Simplifying subcutaneousSubcutaneous injections provide a slow, sustained re-lease of medication and a longer duration of action. Sub-cutaneous injections are used when the total volume in-jected is less than 1 ml of liquid. Drugs commonly admin-istered by the subcutaneous route include insulin,heparin, and epinephrine. (See Sub cue injections.)

Subcutaneous injection sites include the area overthe scapula, the lateral aspects of the upper arm andthigh, and the abdomen.

Mr. MuscleIntramuscular (I.M.) injections are given when rapidabsorption of medication is desired. The onset of actionusually occurs within 10 to 15 minutes after the I.M. in-jection. A larger amount of fluid (between 2 ml and 5 ml,depending on the site) can be administered using I.M.rather than S.C. injections.

Commonly used I.M. injection sites include the dor-sogluteal muscle (in the back of the buttocks), ven-trogluteal muscle (in the anterior portion of the but-tocks), vastus lateralis muscle (in the lateral thigh),rectus femoris muscle (in the upper thigh), and deltoidmuscle (the upper arm muscle that covers the shoulderprominence).

I.V. introMedications are administered by the intravenous (I.V.)route to obtain an immediate onset of action, to attainthe highest possible blood concentration level of a drug,or to treat conditions that require constant titration (in-crease or decrease of dosage according to the patient’sresponse).

I.V. medications can be administered by severalmethods:• direct bolus—the medication is injected directly intothe I.V. catheter over a recommended time interval


Sub cueinjections

In practice, you mayhear a subcutaneous in-jection referred to as asub cue injection—forexample, “Administerthis dose of insulin sub

cue.”

The realworld

I.V. meds

pack a

punch!

845516.qxd 8/19/08 6:53 PM Page 370

• intermittent infusion—the medication is infusedthrough an I.V. catheter at various time intervals• continuous infusion—the medication is infusedthrough an I.V. catheter for a prolonged period.

Other routesOther routes that are used for medication administrationinclude the intrathecal, epidural, intra-articular, dermal,ophthalmic, otic, nasal, sinus, and respiratory routes.

Into the great intrathecal spaceIntrathecal administration involves introducing acatheter into the intrathecal space of the spinal canal fordrug administration. Drugs are delivered by bolus or con-tinuous infusion. Chemotherapeutic agents are some-times administered by this route.

Epidural space travelEpidural administration occurs when a catheter is in-troduced into the epidural space of the spinal column fordrug administration. Drugs are delivered by bolus or con-tinuous infusion. Pain medications are commonly admin-istered by this route.

Joint reliefIntra-articular administration is characterized by in-jecting a drug directly into a joint. Patients with severejoint inflammation sometimes receive intra-articular in-jections of steroids.

Over the topMedications given by dermal or topical administrationare applied directly to the skin. Medications administeredby this route include creams, lotions, ointments, pow-ders, and patches.

Eye it upOphthalmic administration involves instilling liquid orointment medications topically into the eye.

Friends, Romans…lend me your earMedications given by otic administration are adminis-tered topically into the ear.


845516.qxd 8/19/08 6:53 PM Page 371

Nosing aroundNasal or sinus administration refers to the administra-tion of liquid or powdered forms of the drug into the pa-tient’s nose and sinuses by instillation or by an atomizer(a device that changes a jet of liquid into a spray).

On the fast tractRespiratory administration refers to the delivery ofmedications directly into the respiratory tract. Almost allof the drugs administered by this route have a systemiceffect, which means that they affect the entire body be-cause of the rich blood supply in the lungs. The drugforms commonly administered by this route are gas andliquid.

Nebulization is one method commonly used to ad-minister drugs by the respiratory route. There are threetypes of nebulizers:• The ultrasonic nebulizer uses a small volume of med-ication combined with normal saline solution. Air forcedinto the nebulizer delivers the medication in a fine mist.• A metered-dose inhaler requires a nebulizer that’sprefilled by the manufacturer with several doses of thedrug.• A dry-powder inhaler is similar to a metered-dose in-haler. It’s activated by an inhaled breath, and a preciseamount of medication is then delivered.

Drug classifications

Drugs that share similar characteristics are grouped to-gether as a pharmacologic class or family. Terminologyassociated with drugs in each pharmacologic class is bro-ken down according to the body system that’s affected.

Nervous system drugsMany drugs affect the nervous system. They includecholinergic drugs, cholinergic blocking drugs, adrenergicdrugs, adrenergic blocking drugs, skeletal muscle relax-ants, neuromuscular blocking drugs, and anticonvulsantdrugs.


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Copy catsCholinergic drugs promote the action of acetylcholine(a neurotransmitter). These drugs are also calledparasympathomimetic drugs because they produce ef-fects that mimic parasympathetic nerve stimulation.

There are two major classes of cholinergic drugs:• Cholinergic agonists mimic the action of the neuro-transmitter acetylcholine.• Anticholinesterase drugs block the action of the en-zyme acetylcholinesterase (which breaks down acetyl-choline) at cholinergic receptor sites, preventing thebreakdown of acetylcholine.

Cholinergic bustersCholinergic blocking drugs interrupt parasympatheticnerve impulses in the central and autonomic nervous sys-tems. These drugs are also referred to as anticholiner-gic drugs because they prevent acetylcholine from stim-ulating cholinergic receptors.

Similar to the sympatheticAdrenergic drugs are also called sympathomimeticdrugs because they create effects similar to those pro-duced by the sympathetic nervous system. Adrenergicdrugs are classified into two groups based on their chem-ical structure: catecholamines (which stimu-late the nervous system, constrict peripheralblood vessels, increase heart rate, and dilatethe bronchi) and noncatecholamines (whichhave many effects on the body, including localor system constriction of blood vessels, nasaland eye decongestion, bronchiole dilation, andsmooth muscle relaxation).

Adrenergic drugs are also divided by theirmechanism of action:• Direct-acting adrenergics act directly on the organor tissue that’s innervated (supplied with nerves ornerve impulses) by the sympathetic nervous system.• Indirect-acting adrenergics trigger the release of aneurotransmitter, typically norepinephrine.• Dual-acting adrenergics have both direct and indi-rect actions.

373DRUG CLASSIFICATIONS

Adrenergic drugsare also called

sympathomimeticdrugs because they

create effects similar

to those produced by

the sympathetic

nervous system.

845516.qxd 8/19/08 6:53 PM Page 373

The road to disruptionAdrenergic blocking drugs (also called sympatholyticdrugs) are used to disrupt the function of the sympathet-ic nervous system. These drugs work by blocking impulsetransmission at adrenergic receptor sites.

Adrenergic blocking drugs are classified according totheir site of action:• Alpha-adrenergic blockers work by interrupting theactions of the catecholamines epinephrine and norepi-nephrine at alpha receptor sites.• Beta-adrenergic blockers prevent stimulation of thesympathetic nervous system by inhibiting the action ofcatecholamines at beta-adrenergic receptors. (See Tak-ing out the adrenergic.)

Muscle R and RSkeletal muscle relaxants are used to relax skeletalmuscles and treat acute pain or muscle spasticity associ-ated with multiple sclerosis.

Motor end plate stopperNeuromuscular blocking drugs relax skeletal musclesby disrupting the transmission of nerve impulses at themotor end plate (the branching terminals of a motornerve axon).

Seizure silencersAnticonvulsants, also known as antiseizure drugs, in-hibit neuromuscular transmission in order to preventseizure activity.

Pain medicationsDrugs used to control pain range from mild, over-the-counter preparations, such as acetaminophen, to potentgeneral anesthetics. Here’s a list of drugs commonly usedto treat pain:• Nonopioid analgesics are drugs that don’t containopioids but that still control pain. Some of these drugsalso exhibit an antipyretic action, which means theycontrol fever.• Nonsteroidal anti-inflammatory drugs (NSAIDs)control pain by combating inflammation.


Taking out theadrenergic

In practice, the mostwidely used adrenergicblockers are beta-adrenergic blockers,simply referred to asbeta blockers.

The realworld

845516.qxd 8/19/08 6:53 PM Page 374

• Opioid agonists are opium derivatives and syntheticdrugs with similar properties used to relieve or decreasepain without causing the person to lose consciousness.• Opioid antagonists block the effects produced byopioid agonists to reverse adverse drug reactions.• Anesthetic drugs depress the central nervous system(CNS) and produce loss of consciousness, loss of respon-siveness to sensory stimulation (including pain), andmuscle relaxation.

Cardiovascular system drugsTypes of drugs used to improve cardiovascular functioninclude cardiac glycosides and phosphodiesterase(PDE) inhibitors, antiarrhythmics, and antianginal drugs.

Cardiac glycosides and PDE inhibitorsCardiac glycosides and PDE inhibitors increase theforce of the heart’s contractions. This is known as a posi-tive inotropic effect (affecting the force or energy ofmuscular contractions).

Changing the rhythmAntiarrhythmic drugs are used to treat arrhythmias(disturbances in normal heart rhythm).

Stopping heart painAntianginal drugs are used to treat angina (chest pain)by reducing the amount of oxygen the heart needs to doits work, increasing the supply of oxygen to the heart, orboth.

There are three commonly used classes of antiangi-nal drugs:

Nitrates are the drugs of choice for relieving acuteanginal pain. Nitrates cause smooth muscles of the veinsand arteries to relax and dilate. When the vessels dilate,blood flow to the myocardium increases, which relievesthe pain.

Beta-adrenergic blockers are drugs used for long-term prevention of angina. Beta-adrenergic blockers de-crease blood pressure and block beta-adrenergic recep-tor sites in the heart muscle and conduction system. They


Antiarrhythmic

drugs help me

keep my rhythm.

845516.qxd 8/19/08 6:53 PM Page 375

work by decreasing heart rate and reducing the force ofthe heart’s contractions, which results in a lower demandfor oxygen.

Calcium channel blockers are used only for long-term prevention of angina. They prevent the passage ofcalcium ions across the myocardial cell membrane andvascular smooth muscle cells. This causes dilation of thecoronary and peripheral arteries, which decreases theforce of the heart’s contractions and reduces the work-load of the heart.

Pressure droppersAntihypertensive drugs act to reduce blood pressure.Three types of commonly used antihypertensive drugs in-clude:• sympatholytic drugs—which reduce blood pressureby inhibiting or blocking the sympathetic nervous system• vasodilating drugs—which relax peripheral vascularsmooth muscle, causing vessels to dilate, thereby lower-ing blood pressure• angiotensin-converting enzyme (ACE) inhibitors—which reduce blood pressure by interrupting the renin-angiotensin-aldosterone system.

Water worksDiuretics are used to promote the excretion of waterand electrolytes by the kidneys. Major diuretics includethiazide and thiazide-like diuretics, loop diuretics, andpotassium-sparing diuretics:• Thiazide and thiazide-like diuretics work by pre-venting sodium resorption in the kidneys.• Loop diuretics act primarily on the loop of Henle toincrease the secretion of sodium, chloride, and water.• Potassium-sparing diuretics conserve potassium andexert weaker diuretic and antihypertensive effects.

Lower lipid levelsAntilipemic drugs lower abnormally high blood levelsof lipids, such as cholesterol, triglycerides, and phospho-lipids.

Clot stoppersAnticoagulant drugs are used to reduce the ability ofthe blood to clot. Antiplatelet drugs are administered


Antihypertensive

drugs can help

bring a patient’s

blood pressure

down.

845516.qxd 8/19/08 6:53 PM Page 376

to prevent arterial thromboembolism, particularly in pa-tients at risk for myocardial infarction, stroke, and arte-riosclerosis (hardening of the arteries). Antithrombolyt-ic drugs are used to dissolve a preexisting clot or throm-bus, commonly in an acute or emergency situation.

Respiratory system drugsDrugs used to improve respiratory function includemethylxanthines, expectorants, antitussives, mucolytics,and decongestants.

Breathing gone awryMethylxanthines are used to treat breathing disorders.They work by decreasing airway reactivity and relievingbronchospasm by relaxing the bronchial smooth muscle.

Thinner and smootherExpectorants thin mucus so it can be cleared more easi-ly out of airways. They also soothe mucous membranesin the respiratory tract.

Suppress and inhibitAntitussive drugs suppress or inhibit coughing.

Mucus moversMucolytics act directly on mucus, breaking down sticky,thick secretions to make them easier to eliminate.

Oh, what a reliefDecongestants relieve the symptoms of swollen nasalmembranes resulting from hay fever, allergic rhinitis, si-nusitis, and the common cold.

GI system drugsSome classes of drugs that are used to improve GI func-tion include histamine-2 (H2)-receptor antagonists, pro-ton pump inhibitors, antiemetics, and emetics.

Histamine haltersH2-receptor antagonists are commonly prescribed asantiulcer drugs. They block histamine from stimulatingthe acid-secreting parietal cells of the stomach.


H2-receptor

antagonists block

histamine from

stimulating acid

secretion.

845516.qxd 8/19/08 6:53 PM Page 377

Chemical disruptionProtein pump inhibitors disrupt chemical binding instomach cells to reduce acid production, lessening irrita-tion and allowing peptic ulcers to heal.

Opposites don’t always attractAntiemetics and emetics represent two groups of drugswith opposing actions. Antiemetic drugs decrease nau-sea, reducing the urge to vomit. Emetic drugs do just theopposite—they produce vomiting.

Reproductive system drugsVarious drugs may be used to address sexual dysfunction,fertility, and contraception.

When ED comes to visitPhosphodiesterase type 5 inhibitors such as sildenafil(Viagra) are used to treat penile erectile dysfunction(ED). These drugs increase smooth-muscle relaxation,promoting the flow of blood into the corpus cavernosumof the penis.

A helping hand for womenHere are some examples of drugs that help women withfertility and its associated conditions:• Danazol (Danocrine), a synthetic steroid, is used totreat endometriosis, a condition that may decrease fertili-ty. The drug suppresses the hormonal cycle and decreas-es the inflammation associated with endometriosis.• Chlorotrianisene derivatives such as clomiphenecitrate (Clomid) are used to stimulate ovulation.• Progestins such as progesterone gel (Prochieve)improve fertility by supplementing progesterone andimproving the cervical mucus environment.

A helping hand for menFor men with hypogonadism secondary to pituitaryor hypothalamic failure, treatment to improve spermquality may include administering human menopausalgonadotropins (hMGs), human chorionic gonado-tropin (HCG), or pulsatile gonadotropin-releasinghormone (Gn-RH).


There's nothing

wrong with a little

improvement. Men

with hypogonadism

may need drugs such

as HCG to improve

sperm quality.

845516.qxd 8/19/08 6:53 PM Page 378

Preventive medicineContraceptives are hormonal drugs consisting of syn-thetic estrogen and progesterone that are used to preventconception or impregnation. The estrogen suppressesproduction of follicle-stimulating hormone and luteiniz-ing hormone, which then acts to suppress ovulation. Con-traceptives may be administered orally or I.M., or throughtransdermal patches, subdermal implants, and vaginalrings.

Spermicides are inserted into the vagina to kill thesperm before they enter the cervix. Spermicides are avail-able as gels, creams, films, and suppositories.

Maternal health drugsSeveral drugs may be used to treat complications of preg-nancy and labor. Drugs that are known to cause fetalanomalies are called teratogens. These drugs should beavoided unless the benefits of the drug outweigh therisks. (See Tackling teratogen.)

Here are some common maternal health drugs:• Folic acid is a B vitamin that is essential for RBC for-mation and DNA synthesis. Adequate intake of folic acidduring pregnancy has been shown to reduce the inci-dence of fetal neural tube defects.• Tocolytic drugs are used to manage labor or preventpreterm labor by decreasing uterine muscle contractions.• Uterotropic drugs improve uterine contractions bystimulating the smooth muscle of the uterus.

Anti-infective drugsAnti-infective drugs are chosen after the infective organ-ism is identified. Anti-infective agents are effective onlyagainst specific organisms. Anti-infective drugs include:• antibacterial drugs—used mainly to treat systemicbacterial infections• antiviral drugs—used to prevent or treat viral infec-tions• antitubercular drugs—used to treat tuberculosis• antimycotic drugs—used to treat fungal infections.


Tacklingteratogen

A teratogen is anything(such as a drug, an in-fection, or an environ-mental factor) that inter-feres with normal fetalgrowth, causing abnor-mal prenatal develop-ment. It comes from theGreek words teras,

which means monster,and genes, which meansborn or producing.


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Immune system drugsImmune and inflammatory responses protect the bodyfrom invasive foreign substances. These responses canbe modified by certain classes of drugs:• Antihistamines block the effects of histamine on tar-get tissues.• Corticosteroids suppress immune responses and re-duce inflammation.• Noncorticosteroid immunosuppressants preventrejection from transplanted organs and can be used totreat autoimmune disease.• Uricosurics prevent or control the frequency of goutyarthritis attacks.

Psychiatric drugsVarious drugs are used to treat sleep and other psy-chogenic disorders, such as anxiety, depression, andpsychotic disorders.

You’re getting sleepySedatives reduce anxiety or excitement. Some de-gree of drowsiness commonly accompanies sedativeuse. When given in large doses, sedatives are consid-ered hypnotics, which induce a state that resembles nat-ural sleep. The three main classes of synthetic drugs usedas sedatives and hypnotics are:

benzodiazepines, which work on receptors in thereticular activating system of the brain (the portion asso-ciated with wakefulness and attention)

barbiturates, which depress the sensory cortex ofthe brain, decrease motor activity, alter cerebral function,and produce drowsiness, sedation, and hypnosis

nonbenzodiazepine-nonbarbiturate drugs, whichact as hypnotics for short-term treatment of simple in-somnia.

Mood modifiersAntidepressants and antimanic drugs are used to treataffective disorders—such as mood disturbances—thatare typically characterized by intense episodes of depres-sion and elation.


Sedatives

can be used to

induce sleep.

845516.qxd 8/19/08 6:53 PM Page 380

Three drug classes are commonly used to treat affec-tive disorders:• Monoamine oxidase inhibitors (MAOIs) relieve thesymptoms of depression by inhibiting the enzymemonoamine oxidase.• Tricyclic antidepressants (TCAs) effectively treatepisodes of major depression by increasing the amountof chemicals in the brain.• Selective serotonin reuptake inhibitors (SSRIs)are used to treat major depressive episodes by inhibitingthe neuronal reuptake of the neurotransmitter serotonin.

Anxiety criticAnxiolytics, also called antianxiety drugs, are usedprimarily to treat anxiety disorders. Two of the maintypes are benzodiazepines and barbiturates.

Symptoms under wrapAntipsychotic drugs control psychotic symptoms—such as delusions, hallucinations, and thought disorders—that sometimes occur with schizophrenia, mania, andother psychoses.

Endocrine system drugsTogether with the CNS, the endocrine system regulatesand integrates the body’s metabolic activities and main-tains homeostasis.

Too little? Too much?Patients who produce too little thyroid hormone (as inhypothyroidism) may need supplements such as levothy-roxine. Patients who produce too much thyroid hormone(as in hyperthyroidism) may be given drugs such aspropylthiouracil (PTU) to suppress thyroid function.

Sugar up…sugar downInsulin, a pancreatic hormone, and oral antidiabeticdrugs are classified as hypoglycemic drugs becausethey lower blood glucose levels. Glucagon, another pan-creatic hormone, is classified as a hyperglycemic drugbecause it raises blood glucose levels.


Benzodiazepines

and barbiturates are

the two main types of

anxiolytics.

845516.qxd 8/19/08 6:53 PM Page 381



1

2 3

4

5

6 7

8

9

10

Across

5. A drug that’s compressed toform a shape6. Decreased response to a drugover time8. Type of drug that’s administereddirectly into the ear

9. Type of order that allows drugsto be given as needed10. Study of drugs

Down

1. Drug that promotes the action ofacetylcholine2. Drug administered via the respi-ratory route3. Drug interaction in which onedrug enhances the effect of theother drug

4. Increase or decrease of drugdosage according to the patient’sresponse7. process by which a drug is elimi-nated by the body9. Type of inhibitor that increasesthe force of the heart’s contrac-tions

Vocabulary builders

At a crossroadsDon’t get caught up in the conundrum of medication adminis-tration terms. Complete this puzzle to prove that you’vereceived the correct dose of clinical pharmacologyterminology.

845516.qxd 8/19/08 6:53 PM Page 382



Match gameFor some types of drug administration, the location of administration is self-explanatory;for example, intrathecal administration refers to drug administration into the intrathecalspace of the spinal canal. However, other terms used to describe administration routesaren’t so apparent. Match the drug administration route below with its correct definition.

Clues

1. Intra-articular ____

2. Dermal ____

3. Buccal ____

4. Ophthalmic ____

5. Intradermal ____

6. Otic ____

7. Sublingual ____

8. Intravenous ____

Choices

A. Into the skin

B. Under the tongue

C. Into a vein

D. In the ear

E. Between the cheek and gum

F. Into a joint

H. Onto the skin

I. Into the eye

Finish lineThe Greek root pharmaco indicates that a word has to do with drugs. Fill in the blanksbelow to complete the drug-related terms.

1. Pharmaco _____ is the use of drugs to prevent or treat diseases.

2. Pharmaco _____ is the study of the origin, nature, chemistry, effects, and uses ofdrugs.

3. Pharmaco _____ is the study of the biochemical and physical effects of drugs and themechanisms of drug actions in living organisms.

4. Pharmaco _____ is how drugs are absorbed, distributed, metabolized, and excretedin a living organism.

845516.qxd 8/19/08 6:53 PM Page 383


1. F; 2. H; 3. E; 4. I; 5. A; 6. D; 7. B; 8. C

Match game

1. Therapeutics; 2. Logy; 3. Dynamics; 4. Kinetics

At a crossroads

Answers

1C

2I

3P H

N O O4T

H T L I5T A B L E T I T

L N N R

A6T O L E R A N C

7E

N I R T X

T A G I C

T I O R8O T I C C N E

O T9P R N I

D10P H A R M A C O L O G Y

E N

Finish line

845516.qxd 8/19/08 6:53 PM Page 384

Mental health overview

From teenage depression and suicide to increased sub-stance abuse and elderly depression, the risk of mentaldisorders is on the rise. This chapter introduces terms as-sociated with the diagnosis and treatment of mentalhealth disorders. (See Pronouncing key mental healthterms, page 386.)

DSM-IV-TR. Say what?The American Psychiatric Association’s Diagnostic andStatistical Manual of Mental Disorders, FourthEdition, Text Revision (DSM-IV-TR) provides a unifiedsystem of classifying mental disorders. The system re-quires the health care provider to consider many aspectsof the patient’s behavior, mental performance, history,and culture and emphasizes using observable data ratherthan subjective and theoretical impressions. This ap-proach makes psychiatric diagnoses more reliable andhas lead to improvements in treating and managing men-tal health disorders.

17

Health assessmentMental health

Just the facts


♦ terminology related to the definition and assess-ment of mental health disorders

♦ terminology needed for examination of patientswith mental health disorders

♦ tests that help diagnose mental health disorders

♦ terminology related to the types of mental healthdisorders

♦ mental health disorders and their treatments.

The emphasis

in mental health

diagnoses is on

observable data

rather than

subjective and

theoretical

impressions.

845517.qxd 8/19/08 7:00 PM Page 385

Defining mental disordersThe DSM-IV-TR defines a mental disorder as a clinicallysignificant behavioral or psychological syndrome or pat-tern that’s associated with:• current distress (a painful symptom) or disability (im-pairment in one or more important areas of functioning)• significantly greater risk of suffering, death, pain, ordisability• an important loss of freedom.

This syndrome or pattern isn’t an expected, culturallysanctioned response, such as grieving over the death of aloved one. It’s considered a sign of a behavioral, psycho-logical, or biological dysfunction.

Five axesThe DSM-IV-TR uses a multiaxial approach to diagnosingmental disorders. This approach specifies that every pa-tient should be evaluated on each of five axes, as follows:• Axis I: clinical disorders—the diagnosis (or diag-noses) that best describes the presenting complaint and

386MENTAL HEALTH

Below is a list of key terms related to mental health, along withthe correct way to pronounce them.


Pronouncing key mental healthterms

Cyclothymia

Echolalia

Narcissism

Schizoid

Tardive dyskinesia

Tourette syndrome

Wernicke-Korsakoff syndrome

SIGH-KLOH-THIGH-MEE-UH

EK-OH-LAY-LEE-UH

NAR-SIH-SISM

SKIT-SOYD

TAR-DIV DIS-KIH-NEE-ZHUH

TOO-RET SIN-DROHM

VER-NIH-KUH KOR-SEH-KOFF

SIN-DROHM

The multiaxial

approach to

diagnosing mental

health disorders

specifies that every

patient should be

evaluated on each of

five axes.

845517.qxd 8/19/08 7:00 PM Page 386

that indicates the presence or absence of a major mentalhealth disorder• Axis II: personality disorders and mental retarda-tion—determining whether these factors are present• Axis III: general medical conditions—a descriptionof concurrent medical conditions or disorders• Axis IV: psychosocial and environmentalproblems—life events and problems that may affect thediagnosis, treatment, and prognosis of the mental healthdisorder• Axis V: global assessment of functioning (GAF)—based on a scale of 1 to 100, evaluates the patient’s over-all psychological, social, and occupational function.

And now, for the diagnosisA patient’s diagnosis after being evaluated on these fiveaxes may look like this:• Axis I: adjustment disorder with anxious mood• Axis II: obsessive-compulsive personality• Axis III: Crohn’s disease, acute bleeding episode• Axis IV: recent remarriage, death of father• Axis V: GAF = 83.

Psychological examination terms

Here are some important terms to understand when ex-amining a patient with mental health issues.

Assessment terms• Attention level refers to the ability to concentrate ona task for an appropriate length of time.• Behavior includes the patient’s demeanor and overallattitude, mannerisms (such as nail biting, fidgeting, orpacing), tics or tremors, and how he responds to the in-terviewer (for example, cooperative, friendly, hostile, orindifferent).• Chief complaint is the main reason the patient hassought help and includes when symptoms began,whether symptoms are abrupt or gradual, the severity ofsymptoms, how long symptoms last, and how symptomsaffect the patient’s level of functioning.

387PSYCHOLOGICAL EXAMINATION TERMS

845517.qxd 8/19/08 7:00 PM Page 387

• Cultural and religious beliefs include the patient’scultural background and values and how these factors af-fect the patient’s response to illness and adaptation tohospital care. Keep in mind that certain questions or be-haviors considered inappropriate in one culture may beacceptable in another.• Current symptoms are the subjective and objectivesymptoms that are currently affecting the patient, includ-ing their severity and persistence and whether they oc-curred abruptly or gradually.• Demographic data includes the patient’s age, sex, eth-nic origin, primary language, birthplace, religion, andmarital status.• General appearance of the patient helps determinethe patient’s emotional and mental status. When evaluat-ing a patient’s appearance, include information about hisdress, grooming, posture, gait, and facial expression.• Medication history includes information about whatdrugs (including over-the-counter and herbal supple-ments) the patient has taken in the past and what he’scurrently taking. This information is important to collectbecause certain drugs can cause symptoms of mental ill-ness. If the patient is taking an antipsychotic, antidepres-sant, anxiolytic, or antimanic drug, include informationabout whether symptoms have improved or adverse reac-tions have occurred.• Mood refers to the internal emotional state and physi-cal expressions of an individual’s current feelings (for ex-ample, depression, crying, sweating, breathing heavily, ortrembling).• Nonverbal communication (body language) consistsof eye contact, posture, facial expression, gestures, cloth-ing, affect, and silence (which can convey a powerfulmessage). In addition to observing the patient’s nonver-bal communication during the assessment process, you’llneed to be aware of your own.• Patient history helps establish a baseline for futureassessments. It includes the chief complaint, currentsymptoms, psychiatric history, demographic and socio-economic data, cultural and religious beliefs, medicationhistory, and history of physical illnesses that may causedisorientation, distorted thought processes, depression,or other symptoms of mental illness.

388MENTAL HEALTH

Gathering

demographic,

socioeconomic, and

cultural data is an

important part of

diagnosing mental

health problems.

During a mental

health assessment,

be aware of your

nonverbal

communication as

well as the patient’s.

845517.qxd 8/19/08 7:00 PM Page 388

• Psychiatric assessment is the process of identifying apatient’s psychosocial problems, strengths, and concerns.• Psychiatric history includes information about pastpsychiatric disturbances, such as episodes of delusions,hallucinations, violence, attempted suicide, drug or alco-hol abuse, or depression, and previous psychiatric treat-ment.• Socioeconomic data refers to the patient’s economicand personal situation and how it impacts his currentpsychological status. Information may include education-al level, housing conditions, income, and current employ-ment status.• Therapeutic relationship is a relationship betweenthe patient and the health care provider that’s basedon trust. The health care provider’s words and actionsmust communicate to the patient that his thoughts andbehaviors are important.• Thought processes and cognitive function areassessed based on orientation to time, place, and per-son and the presence of confusion or disorientation.Speech characteristics that may indicate alteredthought processes include minimal monosyllabic re-sponses, irrelevant or illogical replies to questions,convoluted or excessively detailed speech, repetitiousspeech patterns, a flight of ideas, and sudden silencewithout an obvious reason.

Signs and symptoms• Acting out involves repeating certain actions to wardoff anxiety without weighing the possible consequencesof those actions.• Compensation (also called substitution) refers to anindividual’s attempt to make up for feelings of inadequa-cy or frustration in one area by excelling or overindulgingin another area.• Compulsion is a ritualistic, repetitive, and involuntarydefensive behavior that’s performed to reduce anxiety,which increases the likelihood that the behavior will re-cur.• Coping mechanisms (also called defense mecha-nisms) are behaviors that operate on an unconscious lev-el to protect the ego.

389PSYCHOLOGICAL EXAMINATION TERMS

Acting out involves

repeating certain

actions to ward off

anxiety without

weighing the possible

consequences of

those actions.

Excessive hand

washing in a

ritualistic, involuntary

manner is an example

of a compulsion.

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• Delusions are false ideas or beliefs accepted as real bythe patient. Delusions of grandeur, persecution, and ref-erence are common in schizophrenia.• Denial is a way of protecting oneself from unpleasantaspects of life by refusing to perceive, acknowledge, ordeal with them.• Displacement refers to misdirecting pent-up feelingstoward something or someone that’s less threateningthan what triggered the response.• Fantasy is the creation of unrealistic or improbableimages to escape from daily pressures and responsibili-ties.• Hallucinations are false sensory perceptions with nobasis in reality. Usually visual or auditory, hallucinationsalso may be olfactory or tactile.• Identification involves unconsciously adopting thepersonality characteristics, attitudes, values, and behav-ior of someone else as a way to alleviate anxiety• Intellectualization (also called isolation) refers toan individual removing himself from emotional events.The patient may discuss painful events in a detached, im-personal way because describing true feelings is too diffi-cult.• Introjection refers to an individual adopting someoneelse’s values and standards without exploring whetherthey’re appropriate for him.• Obsession is an intrusive or inappropriate recurrentidea, thought, image, or impulse that causes marked anxi-ety or distress.• Projection is the displacement of negative feelingsonto another person.• Rationalization is substituting acceptable reasons forthe real or actual reasons that are motivating the patient’sbehavior• Reaction formation refers to the display of behaviorthat’s opposite of the individual’s true feelings.• Regression occurs when an individual returns toan earlier developmental stage.• Repression refers to unconsciously blocking outpainful or unacceptable thoughts and feelings, leav-ing the feelings to operate in the subconscious.• Self-destructive behavior is death-seeking be-havior, including suicidal tendencies.

390MENTAL HEALTH

Regressionoccurs when a

patient returns

to an earlier

developmental

stage.

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• Sublimation is transforming unacceptable needs intoacceptable ambitions and actions. For example, a personwith highly aggressive tendencies may study and excel inthe martial arts.• Undoing refers to an individual trying to undo theharm he feels he has done to others.• Withdrawal refers to growing emotionally uninvolvedby retreating and becoming passive.

Diagnostic tests

Various laboratory tests and psychological and mentalstatus tests provide information about the patient’smental status and possible physical causes of signs andsymptoms.

Laboratory tests• Toxicologic studies are blood and urine tests that candetect the presence of many drugs and quantify the bloodlevels of these drugs. Patients undergoing treatment withpsychotherapeutic drugs may need routine toxicologyscreening to ensure that they aren’t receiving a toxicdose.

Psychological and mental status testsHere are some examples of tests that evaluate the pa-tient’s mood, personality, and mental status:• Beck Depression Inventory helps diagnose depres-sion and determine its severity. This test may provide ob-jective evidence of the need for treatment. It’s also usedto monitor the patient’s response during treatment.• Cognitive Assessment Scale measures orientation,general knowledge, mental ability, and psychomotorfunction.• Cognitive Capacity Screening Examination mea-sures orientation, memory, calculation, and language.• Eating Attitudes Test detects patterns that suggestan eating disorder.• Functional Dementia Scale measures orientation, af-fect, and the ability to perform activities of daily living.

391DIAGNOSTIC TESTS

Toxicologicstudies are blood

and urine tests

that can detect

the presence of

many drugs.

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• Global Deterioration Scale assesses and stages pri-mary degenerative dementia based on orientation, memo-ry, and neurologic function.• Minnesota Multiphasic Personality Inventoryhelps assess personality traits and ego function in adoles-cents and adults. Test results provide information on cop-ing strategies, defenses, strengths, gender identification,and self-esteem. The test pattern may strongly suggest adiagnostic category, point to a suicide risk, or indicatethe potential for violence.• Mini–Mental Status Examination measures orienta-tion, registration (the ability of a patient to name threeobjects previously mentioned to him by the examiner),recall, calculation, language, and graphomotor (the move-ments required in writing) function.

Disorders

This section provides terminology related to mentalhealth disorders, which can affect any age-group.

Disorders of infancy, childhood, and adolescenceHere are some examples of disorders of infancy, child-hood, and adolescence:• Anorexia nervosa is self-imposed starvation resultingfrom a distorted body image and an intense and irrationalfear of gaining weight, even when obviously emaciated. Itmainly affects adolescents.• Attention deficit hyperactivity disorder is a disor-der in which the child has difficulty focusing his atten-tion, engaging in quiet passive activities, or both. Thiscondition is usually diagnosed after age 4 or 5.• Autistic disorder is a severe, pervasive developmen-tal disorder marked by unresponsiveness to social con-tact, gross deficits in cognitive and language develop-ment, ritualistic and compulsive behaviors, restricted ca-pacity for developmentally appropriate activities andinterests, and bizarre responses to the environment.Autistic disorder usually becomes apparent before age 3.• Bulimia nervosa is a disorder marked by eatingbinges followed by feelings of guilt, humiliation, and self-deprecation. These feelings precipitate self-induced vom-

392MENTAL HEALTH

The MinnesotaMultiphasic

Personality Inventoryhelps assess

personality traits and

ego function in

adolescents and

adults.

Anorexia nervosais self-imposed

starvation resulting

from a distorted

body image and an

intense and

irrational fear of

gaining weight.

845517.qxd 8/19/08 7:00 PM Page 392

iting, use of laxatives or diuretics, or strict dieting or fast-ing to overcome the effects of the binges. As with anorex-ia nervosa, this condition usually affects adolescents.• Conduct disorder is characterized by aggressive be-havior. A child with this disorder fights, bullies, intimi-dates, and assaults others physically or sexually, and istruant from school at an early age.• Down syndrome (also known as mongolism and tri-somy 21 syndrome), is a disorder attributed to a chro-mosomal aberration, and characteristically producesmental retardation, abnormal facial features, and otherdistinctive physical abnormalities.• Mental retardation, as defined by the American As-sociation on Mental Retardation, is “significantly subaver-age general intellectual function existing concurrentlywith deficits in adaptive behavior manifesting itself dur-ing the developmental period” (before age 18). This disor-der is transmitted genetically.• Tic disorders are a group of three disorders that in-clude Tourette syndrome, chronic motor or vocal tic dis-order, and transient tic disorder. They involve involun-tary, spasmodic, recurrent, and purposeless motor move-ments or vocalizations. These disorders tend to appearbefore age 21.

Substance-related disordersSubstance-related disorders include alcoholism and drugabuse and dependence, which affect the central nervoussystem, causing physical and mental harm.• Alcoholism is a chronic disorder most commonly de-scribed as the uncontrolled intake of alcoholic beveragesthat interferes with physical and mental health, socialand familial relationships, and occupational responsibili-ties.• Drug abuse is defined by The National Institute onDrug Abuse as the use of a legal or an illegal drug thatcauses physical, mental, emotional, or social harm.

Psychotic disordersCharacterized by disordered thinking, psychotic disor-ders include delusional disorders and schizophrenia.

393DISORDERS

845517.qxd 8/19/08 7:00 PM Page 393

• According to the DSM-IV-TR, delusional disorders(formerly called paranoid disorders) are characterizedby false beliefs despite contradictory information. Delu-sional disorders are known to involve erotomanic,grandiose, jealous, or somatic themes as well as persecu-tory delusions. For example, an individual may believe asexual partner is being unfaithful without any factual in-formation to support the belief.• Schizophrenia is characterized by disturbances inthought content and form, perception, affect, language,social activity, sense of self, volition, interpersonal rela-tionships, and psychomotor behavior. The DSM-IV-TRrecognizes catatonic, paranoid, disorganized, residual,and undifferentiated schizophrenia.

Mood disordersA mood disorder involves disturbances in the regulationof a person’s mood, behavior, and affect. With these dis-orders, a person’s mood becomes so intense and persis-tent that it interferes with his social and psychologicalfunction.• Bipolar disorder is an affective disorder marked bysevere pathologic mood swings from hyperactivity andeuphoria to sadness and depression. Some patients sufferfrom acute attacks of mania only.• Cyclothymia is a variant of bipolar disorder in whichnumerous episodes of hypomania and depressive symp-toms are too mild to meet the criteria for major depres-sion or bipolar illness. (See How do I say cyclothymia?)• Major depression is defined as a depressed mood ona daily basis for 2 weeks or longer. It’s a syndrome of per-sistent sad, dysphoric mood accompanied by distur-bances in sleep and appetite, lethargy, and an inability toexperience pleasure (anhedonia).

Anxiety disordersAnxiety disorders are characterized by apprehension,feelings of tension, and avoidant behavior. Here’s a list ofmajor anxiety disorders:• Generalized anxiety disorder is characterized by afeeling of apprehension caused by a threat to a person orhis values.

394MENTAL HEALTH

How do I saycyclothymia?

Cyclothymia—a mildform of bipolar disor-der—is pronouncedSIGH-KLOH-THIGH-MEE-UH.It’s a combination of twoGreek words, kyklos,

meaning circle or recur-ring, and thymos, mean-ing mind. A patient withthis disorder alternatesbetween episodes of hy-pomania and depression.


Major depressionis defined as a

depressed mood on a

daily basis for 2

weeks or longer.

845517.qxd 8/19/08 7:00 PM Page 394

• Obsessive-compulsive disorder is characterized byobsessive thoughts and compulsive behaviors that repre-sent recurring efforts to control overwhelming anxiety,guilt, or unacceptable impulses that persistently enter theconsciousness.• Panic disorder is characterized by recurrent and un-predictable episodes of intense apprehension, terror, andimpending doom. Panic disorder involves anxiety in itsmost severe form.• A phobia is a persistent and irrational fear of a specificobject, activity, or situation that results in anxiety. A pho-bia causes a compelling desire to avoid the perceivedhazard. Panic attacks can be triggered by the phobia. Ex-amples of phobias include:

– agoraphobia (fear of leaving familiar settings or ofopen space)– social phobia (fear of embarrassing oneself in pub-lic)– pharmacophobia (fear of drugs)– triskaidekaphobia (fear of the number 13). (SeeTaking apart triskaidekaphobia.)

• Posttraumatic stress disorder refers to a persistentpsychological disturbance that occurs following a trau-matic event.

Somatoform disordersThe patient with a somatoform disorder complains ofphysical signs and symptoms and typically travels fromdoctor to doctor in search of treatment. Physical exami-nations and laboratory tests fail to uncover an organic ba-sis for the patient’s signs and symptoms and the somaticsymptoms aren’t due to the effects of alcohol or recre-ational or prescription drugs. Here’s a list of major so-matoform disorders:• Body dysmorphic disorder involves a preoccupationwith an imagined (or, if present, slight) defect in physicalappearance.• Conversion disorder (previously called hystericalneurosis, conversion type) allows a patient to resolve apsychological conflict through the loss of a specific phys-ical function; for example, through paralysis, blindness,or the inability to swallow.

395DISORDERS

Taking aparttriskaideka-phobia

Triskaidekaphobia is anillogical or irrational fearof the number thirteen.Its roots are from theGreek words treis,

meaning three; deka,

meaning ten; and pho-

bos, meaning fear orhaving an aversion to.


845517.qxd 8/19/08 7:00 PM Page 395

• Hypochondriasis (previously referred to ashypochondriacal neurosis) is an unrealistic misinter-pretation of the severity and significance of physicalsigns or sensations. This condition leads to a preoccupa-tion with having a serious disease. This fear persists de-spite medical reassurance to the contrary. (See Feelingill?)• Pain disorder is a persistent complaint of pain. Thepain is severe enough to warrant clinical attention, andsignificantly impairs social, occupational, or other impor-tant areas of functioning.• In somatization disorder, which primarily affects fe-males, the patient has multiple unintentional physicalcomplaints from different systems. The patient’s com-plaints are typically dramatic but inconsistent. Moodchanges and anxiety are common and may be the resultof drug interactions.

Dissociative disordersDissociation refers to an unconscious defense mecha-nism that keeps troubling thoughts out of a person’sawareness. The patient with a dissociative disorder ex-periences temporary changes in consciousness, identity,and motor function.• Depersonalization disorder is characterized by per-sistent or recurrent episodes of detachment. During theseepisodes, self-awareness is temporarily altered or lost;the patient typically perceives this alteration in con-sciousness as a barrier between himself and the outsideworld.• Dissociative amnesia is a sudden inability to recallimportant personal information that can’t be explainedby ordinary forgetfulness.• Dissociative identity disorder is a complex distur-bance of identity and memory characterized by the exis-tence of two or more distinct, fully integrated personali-ties in the same person.

Personality disordersThe patient with a personality disorder possesseschronic, inflexible, and maladaptive patterns of behaviorthat cause social discomfort and impair social and occu-

396MENTAL HEALTH

The patient with

dissociative disorderexperiences

temporary changes in

consciousness,

identity, and motor

function.

Feeling ill?

Hypochondriasis is achronic and abnormalanxiety about imaginarysymptoms and ailments.The ancients thoughtthat this condition wascaused by the disturbedfunction of the hypo-chondria, another namefor the upper abdominalregions.


845517.qxd 8/19/08 7:00 PM Page 396

pational functioning. Here’s a list of major personalitydisorders:• Histrionic disorder applies to an individual who’s ex-cessively emotional and constantly seeking attention.• Schizoid disorder is characterized by emotional de-tachment from other people. The patient is emotionallycold and distant, and he has a limited range of emotionalexpressions.• Antisocial disorder is marked by the disregard for so-cial norms. Patients commonly display deceitful behaviorand don’t show remorse or take responsibility for theiractions.

Sexual disordersThese disorders affect a person’s sexual ability or re-sponse, gender identity, or sexual behavior:• Arousal disorder is the inability to experience sexualpleasure. It’s one of the most severe forms of female sex-ual dysfunction.• Exhibitionism is marked by sexual fantasies, urges, orbehaviors involving surprise exposure of the genitals tostrangers.• Fetishism is characterized by sexual fantasies, urges,or behaviors that involve the use of a fetish—a nonhu-man object or a nonsexual part of the body—to produceor enhance sexual arousal.• Frotteurism is sexual arousal from touching or rub-bing against a nonconsenting person.• Gender identity disorder produces persistent feel-ings of gender discomfort and dissatisfaction.• Orgasmic disorder, the most common type of femalesexual dysfunction, is an inability to achieve orgasm. Thepatient may desire sexual activity and become arousedbut feels inhibited as she approaches orgasm.• Paraphilias are complex psychosexual disorders andare characterized by a dependence on unusual behaviorsor fantasies to achieve sexual excitement. The imagery oracts may involve the use of inanimate objects (especiallyclothing), repetitive sexual activity that includes sufferingor humiliation, or sexual behavior with nonconsentingpartners.• Pedophilia is marked by sexual fantasies, urges, or ac-tivity involving a child, usually age 13 or younger.

397DISORDERS

Other possible sexual

disorders include

dyspareunia, or

painful intercourse,

and vaginismus, the

involuntary spastic

constriction of the

lower vaginal muscles.

Both can lead to a

woman’s lack of

interest in intercourse.

845517.qxd 8/19/08 7:00 PM Page 397

• Sexual masochism is sexual gratification from beingphysically or sexually abused.• Sexual sadism is achieving sexual gratification by in-flicting pain, cruelty, or emotional abuse on others.• Transvestic fetishism involves a heterosexual maledressing in female clothes to produce or enhance sexualarousal.• Voyeurism involves deriving sexual pleasure fromlooking at sexual objects or sexually arousing situationssuch as an unsuspecting couple engaged in sex.

Treatments

Here’s a list of common psychiatric treatments:• Assertiveness training uses positive reinforcement,shaping (modifying existing behavior into desired behav-ior), and modeling (demonstrating desired behavior) toreduce anxiety. It teaches the patient ways to expressfeeling, ideas, and wishes without feeling guilty ordemeaning others.• Aversion therapy uses a painful stimulus to cre-ate an aversion to the obsession underlying the pa-tient’s undesirable behavior.• Behavior therapy assumes that problematic be-haviors are learned and through special training,these behaviors can be unlearned and replaced byacceptable behaviors. Behavior therapy may be usedwith an individual or with a group and may includetreatments such as assertiveness training, aversiontherapy, desensitization, flooding, positive conditions, re-sponse prevention, thought stopping, thought switching,and token economy.• According to cognitive theory, depression stems fromlow self-esteem and belief that the future is hopeless.Cognitive therapy helps identify and change the pa-tient’s negative generalizations and expectations andthereby reduces depression, distress, and other emotion-al problems.• Crisis intervention seeks to help the patient developadequate coping skills to resolve an immediate problem.Therapy focuses on helping the patient resume their pre-crisis functional level. Therapy may include family mem-bers.

398MENTAL HEALTH

Assertivenesstraining uses

positive

reinforcement,

shaping, and

modeling to

reduce anxiety.

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• Desensitization slowly exposes the patient to some-thing he fears.• Detoxification programs offer a relatively safe alter-native to self-withdrawal after prolonged dependence onalcohol or drugs. They provide symptomatic treatment aswell as counseling or psychotherapy on an individual,group, or family basis.• Drug therapy includes the use of antidepressants, an-tianxiety agents, and antipsychotics. This therapy re-quires careful monitoring and possible dosage changes.• Electroconvulsive therapy (ECT) is used for majordepression. After the patient is anesthetized, a tiny elec-tric current is sent to the brain for 1 second through elec-trodes placed above the temples. The current produces aseizure, which lasts 30 seconds to 1 minute. The prevail-ing theory is that ECT temporarily alters some of thebrain’s electrochemical processes.• Family therapy aims to alter relationships within afamily and change the problematic behavior of one ormore of its members.• Flooding (also called implosion therapy) involves di-rect exposure to an anxiety-producing situation. It alsouses the idea that confrontation helps the patient over-come fear.• Group therapy, guided by a psychotherapist, involvesa group of people (ideally 4 to 10) who are experiencingsimilar emotional problems meeting to discuss their con-cerns.• Individual therapy involves a series of therapy ses-sions that promote personality growth and development.It may be short- or long-term.• Milieu therapy uses the patient’s environment as atool for treating mental and emotional disorders. The pa-tient’s surroundings become a therapeutic community,and the patient shares responsibility for establishinggroup rules and policies.• Positive conditioning attempts to gradually instill apositive or neutral attitude toward a phobia. A pleasur-able stimulus is introduced along with the phobic stimu-lus.• Psychotherapy involves a range of approaches—fromin-depth psychoanalysis to 1-day crisis counseling—thataims to change a patient’s attitudes, feeling, or behavior.Types of psychotherapy include individual therapy, group

399TREATMENTS

Drugs used to

treat mental health

disorders include

antidepressants,

antianxiety agents,

and antipsychotics.

845517.qxd 8/19/08 7:00 PM Page 399

therapy, cognitive therapy, family therapy, and crisis in-tervention.• Response prevention seeks to prevent compulsivebehavior through distraction, persuasion, or redirectionof activity.• Thought stopping helps break the habit of fear-inducing anticipatory thoughts by focusing attention oncalmness and muscle relaxation.• Thought switching teaches the patient to replacefear-inducing self-instructions with competent self-instructions.• In token economy, the therapist rewards acceptablebehavior by giving out tokens, which the patient uses to“buy” a privilege or object.

400MENTAL HEALTH

In thoughtswitching, the

patient learns to

replace fear-inducing

self-instructions with

competent self-

instructions.

845517.qxd 8/19/08 7:00 PM Page 400


Across

2. A persistent and irrational fearof a specific object, activity or situ-ation7. An involuntary spastic constric-tion of the lower vaginal muscles9. An unconscious defense mech-anism that keeps troublingthoughts out of an individual’sawareness

11. A dependence on unusual be-haviors or fantasies to achievesexual excitement13. The process of slowly exposingthe patient to something he fears14. Uncontrolled intake of alcohol

Down

1. Growing emotionally uninvolvedby pulling back and being passive3. An intense preoccupation thatinterferes with daily living4. Returning to an earlier develop-mental stage5. Transforming unacceptableneeds into acceptable ambitionsand actions

6. Displacement of negative feel-ings onto another person8. A false sensory perception withno basis in reality10. Pain associated with inter-course12. A false idea or belief that’s ac-cepted as real


Vocabulary builders

1 2 3

4

5

6

7

8

9

10

11

12

13

14

At a crossroadsCompleting this crossword puzzle will help you wrap your headaround mental health terms.

845517.qxd 8/19/08 7:00 PM Page 401

402MENTAL HEALTH

Match gameMatch each description of a disorder to its name.

Clues

1. Characterized by disturbances in thoughtcontent and form, perception, affect, language,social activity, sense of self, volition, interper-sonal relationships, and psychomotor behavior___

2. An uncontrolled intake of alcoholic bever-ages that interferes with physical and mentalhealth, social and familial relationships, andoccupational responsibilities ____

3. Self-imposed starvation resulting from a dis-torted body image and an intense and irra-tional fear of gaining weight ___

4. Involuntary, spasmodic, recurrent, and pur-poseless motor movements or vocalizations___

5. Characteristically produces mental retarda-tion, abnormal facial features, and other dis-tinctive physical abnormalities ___

6. Characterized by recurrent and unpre-dictable episodes of intense apprehension,terror, and impending doom ___

7. Characterized by aggressive behavior ___

8. Allows a patient to resolve a psychologicalconflict through the loss of a specific physicalfunction ___

Choices

A. Anorexia nervosa

B. Conduct disorder

C. Tic disorders

D. Schizophrenia

E. Panic disorder

F. Conversion disorder

G. Alcoholism

H. Down syndrome


I’m thinking.

I’m thinking.

845517.qxd 8/19/08 7:00 PM Page 402



1. ________ includes emotional and physical expressions of current feelings, such asdepression, crying, sweating, breathing heavily, or trembling.

2. Repeating certain actions to ward off anxiety without weighing the possibleconsequences of those actions is called ________ __________.

3. An ______________ is an intense preoccupation that interferes with daily living.

4. Transforming unacceptable needs into acceptable ambitions and actions is called________________.

5. ___________ is returning to an earlier developmental stage.


Done! Done! Done!

I’m really in the mood

to celebrate!

845517.qxd 8/19/08 7:00 PM Page 403

404MENTAL HEALTH

1. D; 2. G; 3. A; 4. C; 5. H; 6. E; 7. B; 8. F

Match game

1. Mood; 2. Acting out; 3. Obsession; 4. Sublimation; 5. Regression

Finish line

At a crossroads

Answers

1W

2P H

3O B I A

I B4R

T5S S E

H U E6P G

D B S R R

R L S O E7V A G I N I S M U S J S

W M O E S

A A N C I

L T8H T O

9D I S S O C I A T I O N

10D O L O

Y N L N

S U

P C

A11P A R A P H I L I A S

R12D N

13D E S E N S I T I Z A T I O N

U L T

N U I

I S14A L C O H O L I S M

A I N

O

N

Great

job!

845517.qxd 8/19/08 7:00 PM Page 404

American Psychiatric Association Diagnostic andStatistical Manual of Mental Disorders, 4th ed.,Text Revision. Arlington, VA: American PsychiatricPublishing, Inc., 2000.

Anatomy and Physiology Made Incredibly Easy, 3rded. Philadelphia: Lippincott Williams & Wilkins,2008.

Bickley, L. Bates’ Guide to Physical Examination andHistory Taking, 9th ed. Philadelphia: LippincottWilliams & Wilkins, 2007.

Cohen, B. Memmler’s The Human Body in Health andDisease, 10th ed. Philadelphia: Lippincott Williams& Wilkins, 2005.

Craven, R.F. Fundamentals of Nursing: HumanHealth and Function, 5th ed. Philadelphia: Lippin-cott Williams & Wilkins, 2007.

Fox, F.I. A Laboratory Guide to Human Physiology:Concepts and Clinical Applications, 12th ed.Boston: McGraw-Hill Higher Education, 2008.

Guide to Clinical Preventative Services. Recommen-dations of the US Preventative Task Force.Rockville, MD: Agency for Healthcare Research andQuality, 2006.

JNC Express. The Seventh Report of the Joint NationalCommittee on Prevention, Detection, Evaluationand Treatment of High Blood Pressure. NIH Publi-cation Number 03-5233, 2003.

Lippincott Manual of Nursing Practice Series: Diag-nostic Tests. Philadelphia: Lippincott Williams &Wilkins, 2007.

Lynn-McHale Wiegand, D.J., and Carlson, K.K., eds.AACN Procedure Manual for Critical Care, 5th ed.St. Louis: Saunders, 2005.

Maternal-Neonatal Nursing Made Incredibly Easy,2nd ed. Philadelphia: Lippincott Williams & Wilkins,2008.

Nursing Procedures, 4th ed. Philadelphia: LippincottWilliams & Wilkins, 2004.

Nursing 2007 Drug Handbook, 27th ed. Philadelphia:Lippincott Williams & Wilkins, 2007.

Orshan, S. Maternity, Newborn, & Women’s HealthNursing: Comprehensive Care Across the Lifespan.Philadelphia: Lippincott Williams & Wilkins, 2008.

Professional Guide to Diagnostic Tests. Philadelphia:Lippincott Williams & Wilkins, 2005.

Professional Guide to Pathophysiology, 2nd ed.Philadelphia: Lippincott Williams & Wilkins, 2007.

Sadock, B.J., and Sadock, V.A., eds. Kaplan andSadock’s Comprehensive Textbook of Psychiatry,8th ed. Philadelphia: Lippincott Williams & Wilkins,2005.

Smeltzer, S.C., and Bare, B.G., eds. Brunner & Sud-darth’s Textbook of Medical-Surgical Nursing, 11thed. Philadelphia: Lippincott Williams & Wilkins,2008.

Stedman’s Medical Dictionary, 28th ed. Philadelphia:Lippincott Williams & Wilkins, 2005.

Stuart, G., and Laraia, M. Principles and Practice ofPsychiatric Nursing, 8th ed. St. Louis: Mosby, 2005.

Taylor, C., et al., eds. Fundamentals of Nursing: TheArt and Science of Nursing Care, 6th ed. Philadel-phia: Lippincott Williams & Wilkins, 2008.

Selected references

405

845518BM.qxd 8/19/08 7:01 PM Page 405

i refers to an illustration; t refers to a table; boldface refers to color pages.

Index

A Abdominal muscles, 76-77Abdominal regions, 32-33, 34iAbdominal surgery, 191Absorption, 360-361Achilles tendon contracture, 85Acids, 151Acne, 108Acquired immunity, 325Activated partial thromboplastin time, 127Acute renal failure, 209Acute respiratory failure, 158Adipose tissue, 27Adolescence, disorders of, 392-393Adrenal glands, 301i, 303-304

disorders of, 313-314Albinism, 108Alimentary canal, 172-176, 173iAllergy testing, 99-100Alopecia, 108Alveoli, 145i, 148, 148i, C7, C8Amenorrhea, 231Amniocentesis, 258Amniotic fluid, 252Amniotic sac, 250Anaphase, 23i, 24Aneurysm, 133-134, 291Angina, 126Angiocardiography, 127, 128Angioedema, 106Angiography, 128Ankylosing spondylitis, 62Anti-infective drugs, 379Anus, disorders of, 188Anxiety disorders, 394-395Aorta, 119, C2Aphthous stomatitis, 108Appendectomy, 193Arm muscles, 77Arrhythmias, 130-131Arterial blood gas analysis, 157, 158Arterial occlusive disease, 133Arteries, 123-124Arteriovenous malformation, 291

treatment for, 294Arthrocentesis, 59Aspiration tests for skeletal disorders, 59-60Asthma, 160Atelectasis, 158-159Atherosclerosis, 132Atria, 118, 120i, C2Atrioventricular valves, 119, 120, 120i, C3Atrophy, 83Audiometric tests, 349Autoimmune disorders, 332-333

Autonomic nervous system, 282

B Bacterial infections of the skin, 101-102Ballottement, 255Balneotherapy, 112Barbiturate coma, 294-295Bartholin’s glands, 224, 225iBases, 152Bile ducts, 173i, 177Biopsy, types of, for skin disorders, 101Birth

disorders associated with, 260-262treatments and procedures associated with,

262-263Bladder, 203, 204iBladder tests, 205-206Blood, 27

disorders of, 329-330diagnostic tests for, 326-329treatments for, 334-335

key terms related to, 320tphysical examination terms related to, 326structure and function of, 319-325

Blood-clotting disorders, 330-331Blood pressure, 124-125Blood tests

for cardiovascular disorders, 127for endocrine disorders, 306-308for gastrointestinal disorders, 181-182maternal and fetal health and, 258-259for muscular disorders, 82for neurologic disorders, 288for skeletal disorders, 59for urinary disorders, 206-207

Blood transfusions, 335Body cavities, 30-31, 32iBody planes, 30, 31iBody sections, 30Body structure, 19-35Body tissues, 25-28Bone marrow, 322Bone marrow aspiration, 329Bone marrow transplantation, 335Bones, 27, 43i, 45i, 50i. See also Skeleton.

anatomy of, 52-54, 54igrowth and resorption of, 54-55movement of, 56-57

Bone tumors, 63Bowel surgery, 191-192Brain, 271, 272i, 273, C13-C16

disorders of, 288-289, 290-291treatments and monitoring tools for,293-294

pathways in, 275-277

Brain stem, 273-274, 275iBreasts, 229, 230iBreath sounds, 154Bronchi, 145i, 147-148, 148i, C5, C7Bronchitis, 158, 159Bronchoscopy, 157, 158iBruit, 126Bunions, 62Burns, 107-108Bursa, 57

C Calluses, 62Candidiasis, 104Capillary, 124Cardiac catheterization, 127Cardiac cycle, 121-123, 122iCardiac enzyme test, 127Cardiac muscle tissue, 27Cardiac output, 123Cardiac troponin test, 127Cardiomyopathy, 132, 133Cardiovascular system, 117-137. See also Heart.


drugs used for, 375-377key terms of, 118tphysical examination terms related to,

124-126Cardioversion, synchronized, 137Carpal tunnel syndrome, 85Cartilage, 27, 55-56Catheters, urinary, 211-212Cavities, body, 30-31, 32iCell-mediated immunity, 325Cells, 19-25

of blood and lymphatic system, 320-322division and reproduction of, 22-24, 23ifluid movement and, 24-25key terms related to, 20tstructures of, 19-21, 21i

Cellulitis, 102Central nervous system

cells of, 267-270, 269iinfections of, 289protective structures of, 278-280, 279i

Cerebrospinal fluid, 280Cerebrospinal fluid analysis, 287, 288Cerebrovascular accident, 291Cervix, 226i, 227Chest tube, 161Chigger, 109Chilblain, 109

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Childhood, disorders of, 392, 393Chronic obstructive pulmonary disease, 159Clitoris, 224, 225iCold injury, 108Colostomy, 192Compression test, 81Computed tomography scanning, 82Conception, 243-245Congenital heart defects, 131-132Connective tissue, 26-27Contractures, 83Coronary artery bypass graft, 136Coronary artery disease, 132Coronary circulation, 119-120, 120i, C4Coronary insufficiency, 134-135Cranial nerves, 280, 281i, C16

disorders of, 290Cryosurgery, 110Cultures, 100Cutaneous ulcers, 107Cyanosis, 126Cystic fibrosis, 159Cystocele, 210Cystoscope, 208iCystostomy, 214iCystourethrography, 208

D Debridement, 111-112Decidua, 250, 251iDegenerative disorders

of the brain, 290-291of the heart, 132-133

Dermabrasion, 110Dermatitis, 105-106Dermatomes, 282Dermatophytosis, 104-105Diabetes insipidus, 312Diabetes mellitus, 311-312Dialysis, 212Diaphoresis, 126Diaphragm, 150Diastole, 121-122Diencephalon, 274Dilatation and curettage, 238Directions, anatomical, 29-30Dislocation, 61Dissociative disorders, 396Distribution, 361Dorsal cavity, 31, 32iDrug administration, 367-372

orders for, 367routes of, 369-372

Drug classifications, 372-381Drug forms, 368-369Drug interactions, 365-367Drug therapy

for blood and lymphatic disorders, 334for cardiovascular disorders, 135for ear disorders, 355

Drug therapy (continued)for endocrine disorders, 315for eye disorders, 353for neurologic disorders, 295for respiratory disorders, 164-165for skin disorders, 109

Dupuytren’s contracture, 85, 86Dysmenorrhea, 231

E Ear

disorders of, 352-353diagnostic tests for, 348-350treatments for, 355

physical examination terms related to, 346structure and function of, 342-344

Echocardiography, 129Edema, 126Ejaculatory ducts, 222i, 223Electrocardiogram, 129Electrocochleography, 349-350Electromyogram, 83Electronystagmography, 350Electrophysiologic studies

for cardiovascular disorders, 128for neurologic disorders, 287

Endocrine system, 299-315disorders of, 309-314

diagnostic tests for, 306-309treatments for, 314-315

drugs used for, 381key terms of, 300tphysical examination terms related to, 306structure and function of, 299-305, 301i

Endoscopic retrograde cholangiopancreatogra-phy, 182-183

Endothelium, 26Endotracheal tube, 161Epidermal appendages, 94-96Epididymides, 222i, 223Epidural space, 279, C15Epithelial tissue, 26Eponyms, 4-5Erectile dysfunction, 236Esophageal surgeries, 190-191Esophagus, 173i, 174

disorders of, 184-185Excretion, 362Excretory urography, 207Extremities

lower, 51-52upper, 49-51, 50i

Eyedisorders of, 350-352


key terms related to, 340physical examination terms related to,

345-346structure and function of, 339-342

F Facial bones, 46Facial muscles, 75Fallopian tubes, 226i, 227Female reproductive system, 224-229, 225i, 226i,

230i. See also Reproductive system.disorders of, 235

Fertilization, 246iFetus

development of, 247, 248i, 249i, 250diagnostic tests for, 258-260engagement and station of, 257iphysical examination terms for, 256-258

Fibromyalgia syndrome, 85Fibrous tissue, 27Fluid movement, cells and, 24-25Fluid tests, maternal and fetal health and,

258-259Folliculitis, 102Footdrop, 83Foot muscles, 79-80Fractures, 61Frontal plane, 30, 31iFungal infections of the skin, 104-105

G Gallbladder, 173i, 177-178Gallbladder surgery, 193Gastric surgery, 191Gastrointestinal system, 171-193

accessory organs of, 173i, 176-178disorders of, 188-189



178-181structure and function of, 171-178, 173i

Gastrointestinal tubes, 190Gestation, 245Gonadotrophic hormone excess, 310Guillain-Barré syndrome, 292Gustatory, 345

H Hair, 94-95Hand, bones of, 50i, 51Hand muscles, 77Haversian systems, 53Head trauma, 291Hearing. See Ear.Hearing loss, 352Heart. See also Cardiovascular system.

miniguide to, C1-C4rhythm of, 121structure and function of, 117-120, 120i

Heart failure, 132

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Hematopoiesis, 41, 321Herniated disk, 62Herpes infections, 102-103Hormones

adrenal, 304pancreatic, 305parathyroid, 303pineal body, 305pituitary, 301-302sex, 223-224thymus and, 305thyroid, 303

Humoral immunity, 324-325Hydrocephalus, 288Hydrophobia, 289Hypersensitivity disorders, 331-332Hypertension, 132Hyperthyroidism, 310-311Hyperventilation, 152, 153iHypothalamus, 274Hypothyroidism, 311Hysterectomy, 239Hysterosalpingography, 233, 234

I Imaging tests

for endocrine disorders, 308-309for eye disorders, 347-348for gastrointestinal disorders, 182-183maternal and fetal health and, 259-260for neurologic disorders, 286-287for urinary disorders, 207-208

Immune system, drugs used for, 380Immunity, 324-325Immunodeficiency disorders, 333Immunoglobulins, 324-325Impetigo, 101-102Impotence, 236Infancy, disorders of, 393Infections

central nervous system, 289eye, 350-351herpes, 102-103muscular, 84skin, 101-105

Inflammationeye, 350, 351muscular, 84

Inflammatory heart disease, 133Integumentary system, 91-112. See also Skin.


function of, 96-97key terms of, 92tphysical examination terms related to, 97-99

Intestines, 173i, 174-176disorders of, 186-187

Intra-aortic balloon counterpulsation, 136

Intracranial pressure monitoring, 293-294Intradermal skin tests, 328-329Intravenous pyelography, 207

J Joints, classifying, 56-57

K Kidneys, 198-203, 200i, 201i, 204i, C9-C12Korotkoff sounds, 125-126

L Labia, 224, 225iLabor

cardinal movements of, 254disorders of, 260-262stages of, 253treatments and procedures for, 263

Laboratory testsfor blood and lymphatic disorders, 327-328for psychotherapeutic drug levels, 391

Larynx, 145-146, 145iLaser surgery for skin disorders, 109-110Leg muscles, 77, 78-79Ligaments, 72Limbic system, 274, 275iLithotripsy, 211Liver, 173i, 176Liver surgery, 193Lochia, 254-255Long bones, 53, 54iLungs, 149, C5-C8Lymph, 322, 323Lymphatic system

accessory organs and tissues of, 323disorders of, 331-333


key terms related to, 320tphysical examination terms related to, 326structure and function of, 319-325

Lymphatic vessels, 323Lymph nodes, 322-323Lysosome, 22

M Magnetic resonance imaging, 83Male reproductive system, 219-224, 222i. See

also Reproductive system.disorders of, 235-236

Maternal health, 243-263. See also Birth, Labor,and Pregnancy.

diagnostic tests associated with, 258-260drugs used for, 379key terms of, 244tphysical examination and, 255-258, 257i

Medical termsdissecting, 1-3pronouncing, 3-4

Meiosis, 24Meninges, 278-279, 279iMenopause, 229Menorrhagia, 231Menostasis, 231Menstrual cycle, 228-229Mental health, 385-400

disorders of, 392-398defining, 386-387diagnostic tests for, 391-392treatments for, 398-400

key terms related to, 386tpsychological examination terms related

to, 387-391Mental status tests, 391-392Mesothelium, 26Metabolism, 361Metaphase, 23, 23iMitosis, 22-24, 23iMohs’ micrograph surgery, 110Mons pubis, 224, 225iMood disorders, 394Mouth, 172-173, 173i

disorders of, 184-185Murmur, 126Muscle biopsy, 82Muscle lesions, 84Muscles

abdominal, 76-77arm and hand, 77facial, 75foot, 79-80leg, 77, 78-79neck and shoulder, 75-76pelvic floor, 77scalp, 74-75structure and function of, 69-70, 71i,

72-73, 74ithigh, 77-78thorax, 76types of, 70, 71i, 72

Muscle tissue, 27-28Muscle tumors, 84Muscular dystrophy, 85Muscular system, 69-86

common complaints of, 80disorders of, 83-85

diagnostic tests for, 81-83treatments of, 86

key terms of, 70tphysical examination terms related to, 80-81

Myasthenia gravis, 85Myocardial infarction, 132Myokinesimeter, 83

N Nails, 95Neck muscles, 75-76Nephron, 199, 201i, C11

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Nephrostomy, 214iNerve surgery, 294Nervous tissue, 28Neural tube defects, 289Neurofibromatosis, 292Neuroglia, 270Neurologic system, 267-295


drugs that affect, 372-374key terms of, 268tphysical examination terms related to,

282-285structure and function of, 267-271, 269i, 272i,

273-282, 275i, 277i, 79i, 281iNeurons, 267-270, 269iNevus, 109Nose, 143-144, 145i, 344. See also Smell, physi-

cal examination terms related to.

O Olfactory, 344Oligomenorrhea, 231Onset, peak, duration, 362Organs, 28-29Osteoarthritis, 62Osteomalacia, 62Osteomyelitis, 62Osteoporosis, 62Ovarian cycle, 228-229Ovaries, 224, 226i, 227-228Oxygen delivery devices, 161, 161i, 162, 162i

PQ Pain medications, 374-375Pancreas, 173i, 178, 301i, 305

disorders of, 311-313Parasitic infections of the skin, 103-104Parathyroid glands, 303

disorders of, 311Patch allergy tests, 328Patellar reflex arc, 277iPediculosis, 103Pelvic floor muscles, 77Penis, 220-221, 222iPercutaneous transluminal coronary angio-

plasty, 136-137Pericardiocentesis, 129Perineum, 224, 225iPeripheral nervous system, 280-282Personality disorders, 396-397pH, 152Phacoemulsification, 354Phalen’s maneuver, 81Pharmacodynamics, 362-363Pharmacokinetics, 359-362Pharmacology, 359-381

key terms of, 360t

Pharmacotherapeutics, 364Pharynx, 144, 145i, 173i, 174Pheochromocytoma, 314Phototherapy, 112Pineal body, 301i, 305Pinkeye, 350, 351Pituitary gland, 300-302, 301i

disorders of, 309-310Placenta, 252-253Planes, body, 30, 31iPlasmapheresis, 295Plural words, forming, 3Pneumoencephalography, 286Pneumothorax, 160Positions, 33, 35iPostpartum period, 254-255Prefixes, 14

common, 6-7tPregnancy

disorders of, 260-261structural changes related to, 250, 251i,

252-2553structures and functions related to, 243-245,

246i, 247, 248i, 249i, 250treatments and procedures for, 262-263

Procedures for skeletal disorders, 60Proetz test, 350Prophase, 22, 23iProstate gland, 222i, 223Psoriasis, 106Psychiatric drugs, 380-381Psychological tests, 391-392Psychotic disorders, 393-394Pudendum, 224, 225iPulmonary artery, 119, 120i Pulmonary edema, 160Pulmonary embolism, 160Pulmonary function tests, 155-156Pulmonary veins, 119, 120i, C2Pulse, 124Pulse oximetry, 157

R Radiation therapy

for endocrine disorders, 315for lymphatic disorders, 334

Radioimmunoassay, 307Radiologic studies

for cardiovascular disorders, 127-128for endocrine disorders, 309for eye disorders, 347-348for gastrointestinal disorders, 182-183for neurologic disorders, 286-287for respiratory disorders, 156-157for skeletal disorders, 60for urinary disorders, 207-208

Radionuclide scan, 128Range of motion, 58Raynaud’s disease, 133

Rectum, disorders of, 188Reflex responses, 277, 285Refraction, 347Reproductive system, 219-239

disorders of, 234-238diagnostic tests for, 232-234treatments and procedures for, 238-239


231-232structure and function of, 219-229, 222i, 225i,

226i, 230iRespiration, 150-152, 153iRespiratory distress syndrome, 160Respiratory patterns, 155Respiratory system, 143-165

disorders of, 158-161diagnostic tests for, 155-157, 158itreatments for, 161-165, 161i, 162i

drugs used for, 377key terms of, 144tphysical examination terms related to,

153-155structure and function of, 143-152, 145i,

148i, 153iRespiratory tract

lower, 145i, 146-149, 148iupper, 143-146, 145i

Reticular activating system, 273Reye’s syndrome, 292Rheumatoid arthritis, 62Ribs, 43i, 49Rickets, 62Roots, 5, 14

common, 8-12tRosacea, 109

S Sagittal plane, 30, 31iSarcoidosis, 160Scabies, 103-104Scalp muscles, 74-75Scratch allergy tests, 328Scrotum, 221, 222iScurvy, 62Sections, body, 30Semilunar valves, 119, 120i, C3Sensory system, 339-355


physical examination terms related to,345-347

structure and function of, 339-345Sexual disorders, 397-398Sexually transmitted diseases, 237-238Shin splint, 83Shoulder muscles, 75-76

409INDEX


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Skeletal system, 41-64common complaints concerning, 58-59disorders of, 61-63


key terms of, 42tphysical examination terms related to, 57-59

Skeleton. See also Bones.anatomy of, 41-42, 43i, 44-47, 48i, 49-52, 50iappendicular, 49-52, 50iaxial, 44-47, 45i, 48i, 49

Skene’s glands, 224, 225iSkin. See also Integumentary system.

epidermal appendages and, 94-96infections of, 101-105layers of, 91-94, 93itouch and, 344-345

Skin color, 97-98Skin grafts, 110-111Skin lesions, 98-99Skin tumors, 106-107Skin turgor, 98Skull, 44-46, 45i, 278, 279iSlit-lamp examination, 347Smear tests, 101Smell, physical examination terms related to,

346. See also Nose.Smooth muscle tissue, 27-28Somatoform disorders, 395-396Spastic paralysis, 83Sphygmomanometer, 125Spinal column, 43i, 46-47, 48i, 278Spinal cord, 274-275

disorders of, 288-289Spinal nerves, 281-282Spinal surgery, 294Spleen, 323, 324Sprain, 83Stenosis, 134Stereotaxic neuroradiography, 287Sternum, 43i, 49Stethoscope, 125Stomach, 173i, 174

disorders of, 186-187Strain, 83Striated muscle tissue, 27Stroke, 291Stye, 102Subarachnoid space, 279i, 280, C15Subdural space, 279-280, C15Subluxation, 61-62Substance-related disorders, 393Sudden infant death syndrome, 161Suffixes, 14

common, 13tSuperior vena cava, 119, C2

Surgeryfor cardiovascular disorders, 135-136for ear disorders, 355for endocrine disorders, 314-315for eye disorders, 353-355for gastrointestinal disorders, 190-193for lymphatic and immune disorders, 335for respiratory disorders, 163for urinary disorders, 212-214, 214i

Sweat glands, 95-96Systole, 121, 122

T Taste, 345

physical examination terms related to,346-347

Telophase, 23i, 24Tendons, 72Teratogen, 379Testes, 221, 222iTesticular torsion, 236Tetanus, 292Tetany, 292Thalamus, 274Thallium stress test, 128Therapeutic baths, 112Thigh muscles, 77-78Thoracentesis, 157Thoracic cage, 149-150Thorax muscles, 76Thrombophlebitis, 133Thrush, 104-105Thymus, 301i, 305Thyroid gland, 301i, 302-303

disorders of, 310-311Tinea infections, 104Tinel’s sign, 81Tissues, 25-28Tonometry, 347Torticollis, 85Touch, 344-345Tourette syndrome, 292Trachea, 145i, 146, C5Tracheostomy tube, 162, 162iTransverse plane, 30, 31iTuberculosis, 161Tuning fork tests, 349Tzanck test, 100

U Urethra, 203Urethral meatus, 224, 225iUrinary diversion, types of, 214, 214iUrinary system, 197-214

disorders of, 209-211diagnostic tests for, 205-208, 208itreatments for, 211-214, 214i

key terms of, 198t

Urinary system (continued)physical examination terms related to,

204-205structure and function of, 197-203, 200i,

201i, 204iUrine tests

for endocrine disorders, 308for muscular disorders, 82for urinary disorders, 205-206

Uterus, 226-227, 226i

V Vagina, 225, 226iVascular disorders

cardiovascular, 133-134neurologic, 291-292

Vascular system, 123-124Vas deferens, 222i, 223Veins, 124Ventilation and perfusion, 150, 151Ventilation tests, 155-156Ventilation therapies, 163-164Ventral cavity, 30-31, 32iVentricles, 118, 120i, C2Ventricular assist device, 137Vertebral column. See Spinal column.Viral infections of the skin, 102-103Vision. See Eye.Visual acuity tests, 348Vital signs, 124-125Vitiligo, 109

WX Warts, 103Wood’s light, 101Words, components of, 5, 6-13t, 14

YZ Yolk sac, 252

410INDEX


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