Laboratory Manual for

BSC 2093CHuman Anatomy and Physiology I

Laboratory Manual for

BSC 2093C

Human Anatomy and Physiology I

Compiled by the Faculty of Lake-Sumter Community College

Fall 2011

Table of ContentsLaboratory Rules

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Exercise One The Human Skull 5

Exercise Two The Human Skeleton 11

Exercise Three Human Muscles 19

Exercise Four Special Senses 29

Exercise Five The Human Brain 37

LABORATORY RULES

A science laboratory js not a risk-free environment. All students must take responsibility for knowing and following a few simple rules and guidelines to maintain their own safety, and the safety of others working in the lab.

1. Please do not bring food or beverages into the laboratoty.

When working in a science or medical laboratory it is best to assume that every surface - every table, chair, or piece of equipment - is a potential source of contamination. Even surfaces that look clean may have dried chemical or biological residue on them, which will transfer easily to hands and clothing. Anything you put in your mouth, nose or eyes while in the laboratory may contain noxious or dangerous substances, so eating, drinking and the application of cosmetics should not occur in the lab.(Sneaking while the teacher isn't looking doesn't make it safer!)

2. Appropriate clothing must be worn while working in a science laboratory.Students are required to wear closed-toe shoes before being allowed entrance into the laboratory. Students wearing sandals, flip-flops, peeptoes, sling-backs, slides, clogs, crocs or other footwear with openings in the sides will be denied access to the lab. Students should avoid wearing to lab short shorts, tube and tank tops, short skirts or other clothing that leaves a lot of skin exposed. Long hair should be tied back off the face. Dangling jewelry should be removed.

3. Students are expected to behave in a mature and self-controlled manner.•mere is no running, jumping, shouting, or throwing things allowed in the laboratory. Students should keep their hands to themselves; even 'playful" hitting, slapping or punching is strictly forbidden. Laboratory materials are for laboratory study and use only. Hazardous mis-use of laboratory materials is cause for immediate ejection from the room.

4. Report any injuries or other health problems immediately.

A small first-aid kit is supplied to each laboratory. Simple injuries such as cuts or small burns can be treated on-site. Each lab room meets or exceeds federal standards for ventilation. Students with allergies or chemical sensitivities should report such problems to their instructor before entering the lab. Student should familiarize themselves with the location of the safety shower, eyewash stations, and emergency exits.

5. Keep the laboratory room clean and tidy.

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Please store personal possessions out of the way of foot traffic. Care should be taken with the wheeled laboratory chaiß to avoid slipping and falling (for example, do not attempt to sit with one leg curled up on the seat cushion). Return laboratory materials to their place. Dispose of trash in the trash container. Wipe up any spilled liquids immediately. If necessaty your instructor will provide additional instruction on clean-up or decontamination procedures.

6. Wash your hands with soap and water before leaving the laboratory.

Hand sanitizers do not remove dirt, oils, dyes, biological fluids or other potential contaminants. In fact, the alcohol in most sanitizers may drive some chemicals deeper into the skin, making later removal more difficult and increasing their potential damage.

7. PAY ATTENTION!

Your instructor is more knowledgeable and better informed on potential safety hazards in the laboratory than you. Listen carefully to instructions on the proper use and handling of all laboratory equipment, solutions, materials and supplies. In the event of an accident or other emergency, follow your instructor's directions immediately and without argument.

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EXERCISE ONE: The Human SkullObjective: Students will learn to identify and correctly name the bones and various features of the human skull.

Materials: Life-size medical-quality skulls or skull models, blunt probes, textbook and/or human anatomy atlases.

Students may work individually or in groups

Before you begin

Most parts of the human body visible to the naked eye were identified and named thousands of years ago by ancient Greek and Roman physicians. So most anatomical names are either in Greek or Latin, or are latinized. You will find it useful to familiarize yourself with the more common Latin and Greek roots of the names, and with the modern language meanings of words that appear frequently in anatomical studies. Below is a short list of words you will encounter in your study of the skull and, later, the skeleton. Take a few minutes to look them up in your text, or other sources, and write their meanings next to them:

condyle -

epicondyle -

facet -

foramen -

fossa -

lamina -

meatus -

ramus -

suture -

trochanter —

tubercle -

tuber si

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Structures to identify:

The following list is organized by position or viewing aspect. It is important that students be able to identify a bone or structure regardless of the skull's position or orientation. Therefore, the list tends to be redundant, listing the same bones, structures and features several times.

Frontal or Anterior View(skull is looking back at you)

bones: structures or features:

frontal perpendicular plate of the ethmoidlacrimal infraorbital foramenethmoid mental foramennasal supraorbital foramensphenoid middle nasal conchazygomatic optic foramen (also called optic canals)maxilla zygomatic archvomer orbital forameninferior nasal concha

Warning — watch yourspe///ng! Foramen are NOT the same as "foremen.Superior View

(looking down on the top of the skull)bones: structures or features:

frontal coronal sutureparietal sagittal suturetemporal lambdojdal sutureoccipital nasal

zygomatic arch

Lateral View(side)

bones: structures or features:

frontal coronal suture

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temporal lambdoidal suturezygomatic squamousal sutureparietal external auditory (acoustic) meatussphenoid mastoid processnasal styloid processlacrimal zygomatic process of the temporal boneethmoid temporal process of the zygomatic bonemaxilla zygomatic archmandible mandibular condyleoccipital coronoid process

Inferior View(looking at the bottom)

For some features you may find it useful to temporarily remove (if possible) the

mandible.bones: structures or features;

occipital mastoid processtemporal styloid processzygomatic external auditory meatussphenoid foramen magnumvomer foramen ovatepalatine foramen lacerummaxilla palatine process of the maxillamandible horizontal plate of the palatine bone

hard palate occipital condyles medial pterygoid lamina of the sphenoid lateral pterygoid lamina of the sphenoid zygomatic arch mandibular fossa incisive foramen jugular foramen

Posterior View(back of the head)

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bones: stuctures or features:

parietal sagittal sutureoccipital lambdoidal suturemandible squamousal suturetemporal mandibular

foramen mastoid process styloid process mandibular condyle

Cranial Cavity(remove the top of the skull and look inside)

bones: structures and features:

frontal foramen magnumethmoid Crista galli in Latin, a rooster's comb

sphenoid cribiform platetemporal olfactory foraminaoccipital sella turcica in Latin, a Turkish saddle

parietal petrous portion or petrous ridge of the temporal bone internal auditory (acoustic) meatus foramen rotundum foramen ovale foramen lacerum

Your instructor will explain the specifics of your exam on the skull. In general the exam is "practical" in nature, meaning that skulls will be tagged with stickers and you will be asked to correctly identify the bones or structures indicated; your instructor may prefer to point to the features and prompt you orally.

Spelling coun&! Many anatomical names are very similar in spelling, and even small mistakes can alter the meaning of the words. Sloppy spelling can lead to serious misunderstandings, so do not expect your instructor to "know what you mean." They won't, and you w///lose points!

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EXERCISE TWO: The Human SkeletonObjectives: Students will learn the names and locations of the bones of the human skeleton and various identifying structures and features.

Materials: Disarticulated human skeletons or skeleton models, textbooks and skeleton atlases, blunt probes. Students will work in groups.

Before you begin

Your instructor will allow several weeks for the study of the skeleton and preparation for the laboratory practical exam. It is impottant that you use this time wisely and not wait until the last moment to try to learn all of the bones and structures. One way of organizing your time is:

First week — work to identify just the bones. Set the skeleton out on the lab bench in approximate anatomical position. Identify superior and inferior positions, left and right bones (where possible) and numbers of bones.

Second week - review the names and positions of the entire skeleton, then focus on the bones of the axial skeleton. Identify and be able to name the specific bones and their characteristic structures and features.

Third week — review material from the first two weeks, then focus on the bones of the appendicular skeleton. Be able to name the specific bones and their identifying features and structures.

-me Learning Center has a skeleton for additional review at times the lab is not available to you.

Your instructor will give you more information on the laboratory exam on the skeleton. In general it is a "practical" exam with the bones tagged with numbered stickers at stations around the room; you will move from station to station and identify the tagged features. Spelling counG Many of the bones and structures have similar names and even minor spelling errors can make a word unrecognizable. Your instructor will notknow what you mean and will not give you the benefit of the doubt.

Be able to identi&:

Axial Skeleton

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Vertebrae

Atlas (Cl) From the Greek myth of the god who carried the globe of the world on his shoulders vertebral foramen transverse foramen transverse process fovea dentis

Axis (Q) vertebral foramen dens (also called the odontoid process) Greek for "tooth" spinous process transverse process transverse foramen

Typical cervical vertebrae (C3-C7) vertebral foramen body spinous process Notice that the spinous pmcess is often "bifid," or forked transverse process laminaC7 on/yvertebra prominens

Typical thoracic vertebrae (Tl-T12) vertebral foramen body spinous process transverse process superior articular process inferior articular process pedicle Latin for "little foot" lamina Latin for "thin layer" articular facet for the ribs Latin for "little face.' This feature may be more visible on real bone vertebrae

Typical lumbar vertebrae (Ll-L5) vertebral foramen spinous process transverse process body superior articular process inferior articular process lamina pedicle

If you were shown just one vertebra, could you identify it as cervical, thoracic or lumbar? What features can you use to distinguish between the types?

How many of each type of vertebrae are found in the human skeleton?

Additional axial bones

Sacrum tubercles of medial sacral crest auricular surface Latin for "ear-like" sacral promontory superior articular process sacral foramen Many texts identify these holes as "anterior sacral foramen" and "posterior sacral foramen" depending on which side you are viewing. They are the same holes, passages for nerves and blood vessels.

Greek for "cuckoo;" similar in shape to bird's beak

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SternumThe sternum is formed by the fusion of three bones, the manubrium Latin for *'pot handle" body xiphoid process Greek for "sword" costal cartilages Watch the spelling - costal, not coastal

Ribs head neck shaft sternal (anterior) end tubercle Latin for "small swelling"

How many pairs of ribs are typically found in the human body?

What is the definition of a true rib?

What is the definition of a false rib?

How do you tell the difference between a floating rib and other types of ribs?

How many pairs of true ribs, false ribs and floating ribs are in a human body?

You will not be asked to identify individual ribs by position or number. However, you may be asked to differentiate between attached and floating ribs, or explain the difference bewveen true and false ribs.

Appendicular Skeleton

Pectoral girdle

Clavicle Latin for "little key" sternal end acromia' end

Scapula axillary border vettebral bordersuperior border Be able to distinguish

betweenventral (costal) surface right and left scapula bonesdorsal surface acromion process coracoid process Greek for "crow's beak" glenoid cavity Greek for

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"shallow form" scapular notch (also called the suprascapular notch) spine

Arm and hand

Humerus headanatomical neck surgical neck greater tuberclelesser tubercle Be able to distinguish

betweenjntertubercular groove shaft

right and left humerus bones

deltoid tuberosity Named for the Greek letter delta A. Where the deltoid muscle attaches lateral epicondyle medial epicondyle trochlea Latin for "spool" or "pulley" capitulum Latin for "little head" coronoid fossa olecranon fossa nutrient foramen (more easily seen on real bones)

Note - nutrient foramen, the holes left by blood vessels and nerves, are seen on many bones, not just the humerus.

trochlear notch coronoid process olecranon process radial notch head styloid process A stylus is a pointed tool for marking clay or wax

Radius head radial tuberosity styloid process ulnar notch

Carpals Be able to identify the group or type of bones. The individual bones are sometimes used for extra credit questions. trapezium Greek for "small table" trapezoid capitate Latin for "head" scaphoid Greek for "boat-like" pisiform Greek for "pea-shaped"

triquetrum Latin for "three-cornered" hamate Latin, a hook lunate Latin, moon- or crescent-shaped

Metacarpals

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Phalanges

Pelvic girdle

Os coxae (pelvic bones) The coxal bones are formed from the fusion of three bones, the ilium, the ischium and the pubis. Be able to identify the regions of each of the three on the larger os coxa. You should also be able to distinguish between right and left pelvic bones. iliac crest obturator foramen Latin for "closed up." Same root as "obtuse." acetabulum In Roman times vinegar-based sauces were served in a cup called an acetabulum (acetic acid has the same root) spine of ischium ischial tuberosity greater sciatic notch superior ramus of the pubis inferior ramus of the pubis ramus of the ischium symphysis pubis

Leq and foot

Femur greater trochanter Greek for "runner" lesser trochanter intertrochanteric crest head Be able to distinguish between neck right and left femur bones lateral condyle medial condyle intercondylar fossa shaft linea aspera Latin for "rough line"

Patella

Tibia In Roman times a tibia was a flute-like musical instrument medial condyle lateral condyle Be able to distinguish between tibial tuberosity right and left tibia bones medial malleolus l.atin for "little hammer"

Fibula Latin for clasp or brooch head lateral malleolus

Watch your spelling - there is no such bone as a "fibia" or "tibula!'Tarsals Be able to identify the group or type of bones. The individual bones are sometimes used for extra credit questions. calcaneus talus cuboid navicular Latin for "boat-shaped;" the word "navy" has the same root lateral cuneiform Latin for "wedge-shaped" intermediate cuneiform medial cuneiform

Metatarsals

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PhalangesNotice that the big toe has only two phalanges, while the other toes have three. Was there a similar arrangement in the phalanges of the hand?

Review activities:

1. Close your eyes and have a lab partner place a bone in your hands. Try to identify the bone by touch alone. Don't peek!

2. Call out the name of a bone or structure and have your partner point to it. Point to a bone or structure and have your partner name it. Mix up the sequence so they can't use the order as a clue.

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EXERCISE 3: Human MusclesObjective: Students should learn the names, locations and functions of selected muscles and muscle groups of the human body.

Materials: Students will use anatomical models of arms, legs and torsos.

Before you begin: During the lab periods assigned for this exercise students may work individually or in groups. Additional study material is available at the Learning Center (Leesburg campus) and the college libraries (South Lake and Sumter campuses).

In general a skeletal muscle is attached to two individual bones. When the muscle contracts, one bone remains relatively stationary. The site of attachment of the muscle to the stationary bone is called the origin. When the muscle contracts the other bone is forced to move. The site of attachment to the moving bone is called the insertion.

You will not be asked to memorize the origins and insertions of the individual muscles, but knowing where and how muscles are attached to bones will help you understand their functions.

It is also useful to know the definitions of terms that are used to describe muscle and joint actions. Use your text or other information source to learn the definitions of the following terms (usually found in the chapter on joints and articulations): Flexion -

Extension -

Plantar flexion —

Dorsiflexion —

Abduction Adduction Elevation -

Depression —

Supination -

Pronation —

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Circumduction or rotation -

Procedure:

Be able to identify the following muscles by name (correct spelling) and function. Keep in mind that functions are described starting from the anatomical position. "T" means the muscle can be seen on the anatomical torsos. "A" means it is visible on the arm models, and 'N L" means it is visible on the leg models. Some muscles are displayed on more than one model, or at more than one location on the same model.

1. Frontalis (T) - raises eyebrows and wrinkles forehead

2. Temporalis (T) - elevates mandible

3. Orbicularis oculi CD — closes eyelids

4. Orbicularis oris CT) — closes lips, protrudes lips

5. Masseter CD - elevates mandible

6. Zygomaticus major and minor CT) — elevates corners of mouth and upper lip

7. Mentalis (T) — moves lower lip forward

8. Buccinator CD - tenses cheeks

9. Platysma (T) — draws lower lip and corner of mouth downward as when pouting, depresses mandible

10. Occipitalis (T) - retracts scalp, raises eyebrows

11. Sternocleidomastoid (T) - flexes and rotates neck; or elevates sternum

12. Trapezius CT) - rotates scapula, extends and rotates neck

13. Latissimus dorsi (T) - adducts, extends and medially rotates shoulder (pulls shoulder downward and back)

14. Infraspinatus (T) — rotates arm and shoulder laterally

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15. Pectoralis major (T) — adducts, flexes and medially rotates arm at shoulder

16. Pectoralis minor (T) - depresses scapula, elevates ribs

17. Serratus anterior (T) - rotates scapula, elevates ribs

18. External (abdominal) oblique (T) - flexes and rotates vertebral column, depresses ribs, compresses abdomen

19. Internal (abdominal) oblique (T) - flexes and rotates vertebral column, depresses ribs, compresses abdomen

20. Transverse abdominis (T) — compresses abdomen

21. Rectus abdominis (T) - compresses abdomen, depresses ribs, flexes vertebral column

22. Linea alba (T) — this structure, made of dense proper connective tissue, is an unusual type of tendon called an aponeurosis. Most tendons connect a muscle to a bone; an aponeurosis connects a muscle to another muscle. The linea alba (Latin for "white line") connects the right and left rectus abdominis muscles to each other and is a major surgical landmark.

23. Deltoid (T, A) - abducts, extends and flexes the arm at the shoulder

24. Subscapularis (T, A) — rotates arm medially

25. Biceps brachii (T, A) - flexes forearm at elbow and rotates hand laterally

26. Triceps brachii (T, A) — extends forearm at elbow

27. Teres major (T, A) - extends, adducts and rotates arm medially

28. Teres minor (T, A) - rotates arm laterally

29. Brachialis (A) - flexes forearm at elbow

30. Brachioradialis (A) — flexes forearm at elbow

31. Extensor carpi radialis longus (A) - extends hand at the wrist

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32. Extensor carpi radjalis brevis (A) — extends hand at the wrist

33. Flexor carpi ulnaris (A) - flexes hand at wrist

34. Extensor carpi ulnaris (A) — extends hand at the wrist

35. Extensor digitorum (A) — extends wrist and fingers, spreads fingers apart

36. Pronator teres (A) - rotates forearm medially

37. Flexor carpi radialis (A) — flexes hand at wrist anteriorly

38. Palmaris longus (A) - flexes hand at wrist

39. Gluteus maximus (T, L) — extends thigh at hip, abducts thigh, elevates trunk from stooping position

40. Gluteus medius (T, L) - abducts and medially rotates thigh

41. Tensor fascia latae (T, L) — flexes and medially rotates hip, stabilizes pelvis and thigh during standing

42. Sartorius (T, L) — flexes and laterally rotates hip

Quadriceps group

43. Rectus femoris (T, L) - extends leg at knee

44. Vastus medialis (L) - extends leg at knee

45. Vastus lateralis (L) — extends leg at knee

46. Vastus intermedius (L) - extends leg at knee

47. Adductor longus (T, L) — adducts, flexes and medially rotates leg at hip

48. Adductor magnus (L) - adducts, extends and rotates thigh laterally

49. Gracilis (L) - adducts thigh and flexes leg at the knee

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Hamstrings group

50. Semitendinosus (L) - flexes knee, extends and medially rotates leg at hip

51. Semimembranosus (L) - flexes knee, extends and medially rotates leg at hip

52. Biceps femoris (L) - flexes knee, extends and laterally rotates leg at hip

53. Tibialis anterior (L) - dotsiflexion and inversion of foot

54. Extensor digitorum longus (L) — dorsiflexion and eversion of foot, extends toes 2-5

55. Fibularis (previously Peroneus) longus (L) — plantar flexion and eversion of foot

56. Fibularis (Peroneus) brevis (L) - plantar flexion and eversion of foot

57. Gastrocnemius (L) - flexes leg at knee, plantar flexion of foot

58. Soleus (L) — plantar flexion of foot

59. Achilles tendon (L) — also called the calcaneal tendon; connects several muscles of the lower leg to the calcaneus bone of the heel, permitting plantar flexion of the foot and flexion of the lower leg.

(How did the Achilles tendon get its name?)

Ask your instructor or consult your syllabus about the scheduling and operation of the exam concerning muscle names and functions. In general the exam is a 'practical" or 'tag test." For written exams it is very important that you be able to spell the names of the muscles correctly and completely. Even small errors can cause big confusion. For example, there is a muscle called "biceps brachii," and another called "biceps femoris." If a students supplies the answer "biceps,' it is NOT clear which muscle is being identified, and the student will lose points.

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Key to Muscles of the Arm

A. Muscles, Ligaments, and Tendons

1. Supraspinatus muscle2. Infraspinatus muscle3. Teres major muscle4. Teres minor muscle5. Latissimus dorsi muscle6. Subscapularis muscle7. Deltoid muscle8. Pectoralis major muscle9. Biceps (brachii)10. Brachialis muscle11. Triceps muscle12. Pronator teres muscle13. Flexor carpi radialis14. Palmaris longus muscle15. Flexor carpi ulnaris16. Extensor carpi ulnaris muscle17. Extensor digitorum muscle18. Extensor carpi radialis brevis muscle19. Extensor carpi radialis longus muscle20. Brachio-radialis muscle21. Tendon of the Extensor pollicis longus

muscle22. Extensor pollicis brevis muscle23. Abductor pollicis longus muscle24. Flexor digitorum sublimis25. Supinator muscle26. Volar fascia27. Extensor retinaculum28. Flexor pollicis brevis29. Abductor pollicis brevis muscle30. Adductor pollicis muscle31. Opponens pollicis muscle32. Opponens digiti minimi muscle33. Flexor digiti minimi34. Abductor digiti minimi muscle35. Lumbrical muscles36. Dorsal interosseous muscles of the hand

37. Flexor retinaculum of upper limb38. Tendon sheath

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39. Crucial sffings of the tendon sheath40. Annular strings of the tendon sheath41. Tendon of the flexor pollicis longus42. Tendons of the flexor digitorum sublimis43. Tendons of the flexor digitorum profundus

44. Chiasma tendinum

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B. Arteries

45. Axillary artery46. Subscapular artery47. Circumflex scapular artery48. Posterior circumflex humeral artery49. Brachial artery50. Profunda brachii artery51. Ramus deltoideus52. Medial collateral artery53. Radial collateral artery54. Superior ulnar collateral artery55. Radial artery56. Ramus palmaris superficialis57. Ramus carpeus dorsalis58. A. metacarpea dorsalis I59. Ulnar artery60. Common interosseous artery

Key to Muscles of the Leg with Base of Pelvis

A. Muscles1. Psoas major muscle2. Jliacus muscle3. Gluteus maximus muscle4. Gluteus medius muscle

5. Piriformis muscle6. Obturator internus muscle7. a) Superior gemellus muscle7. b) Inferior gemellus muscle8. Quadratus femoris muscle

9. Tensor fasciae latae muscle10. Satorius muscle a-b-c-d) Quadriceps

femoris musclea) rectus femoris muscleb) vastus medialis musclec) vastus lateralis muscled) vastus intermedius musclee) common tendon of the muscles

12. Pectineus muscle13. Adductor longus muscle14. Adductor magnus muscle15. Gracilis muscle16. Semitendinosus muscle

17. Semimembranosus muscle18. a-b) Biceps femoris19. Tibialis anterior muscle20. Extensor hallucis longus muscle21. Extensor digitorum longus muscle

22. Preoneus longus muscle

23. Peroneus brevis muscle24. -b-c) Triceps surae muscle and b) Gastrocnemius muscle

(a—Caput mediale, b=Caput laterale) c) Soleus muscled) Achilles tendon

25. Plantaris muscle26. Popliteus muscle27. Flexor digitorum longus28. Tibialis posterior muscle29. Flexor hallucis longus30. Extensor hallucis brevis muscle31. Extensor digitorum brevis muscle32. Abductor hallucis muscle33. Flexor hallucis brevis34. Abductor digiti minimi muscle35. Flexor digiti minimi brevis36. Flexor digitorum brevis37. Lumbrical muscles38. Dorsal -interosseous muscles of the foot

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EXERCISE FOUR: Special SensesObjective: To familiarize students with the structures and functions of the eye and ear.

Materials: Anatomical models of eye and ear, text books and/or atlases, otoscopes and opthalmoscopes

Students will work individually or in groups.

Background:

If you ask most people "how many senses do humans have?" the usual answer is "five." Sometime in childhood we learn the five senses of sight, hearing, taste, touch and smell. Humans really have many more senses than just five, including, heat, cold, pain, balance and motion. In addition we have a number of internal, subconscious senses such as blood pressure and inflation of the lungs. The traditional senses of sight, hearing, taste and smell, plus equilibrium, are sometimes referred to as the special senses because of the complex structures through which we perceive these sensations.

In this laboratory exercise you will become familiar with the structures of the eye and ear, and gain some understanding of how those structures produce the sensations of sight, sound, balance and motion. Use the models available in the laboratory, plus a close examination of the illustrations and explanations in your text book.

Eye

External anatomy:

Use a lab partner, or a mirror, and look carefully at the human eye. Consult illustrations of eye anatomy in your text or other sources. Notice the

1. eyebrows — superior to the eye on the supraorbital ridge. These patches of short, coarse hair protect the eye from sunlight and block trickling sweat.

2. eyelids - two sheets of connective tissue covered by thin skin, one "upper" lid and one "lower" lid per eye. Small muscles are attached to the lids to produce blinking.

3. eyelashes - short, coarse hairs along the free edges of the eyelids. The follicles of these hairs have many touch receptors, so that even the lightest touch of the eyelash produces reflex blinking.

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4. conjunctiva - transparent mucous membranes that line the eyelids and cover the whites of the eye. Numerous small glands produce a lubricating secretion that allows the eyelids to move smoothly and moisturizes the eye surface. When we sleep these secretions may accumulate in the corners of the eye and dry, producing the "sandman" crystals of childhood myth.

5. lacrimal gland — superior to the eye and slightly lateral of the midline. (Not visible in an intact face) ms gland produces the dilute saline lacrimal solution also called 'tears." Lacrimal solution is secreted through numerous small ducts onto the conjunctiva of the upper eyelids. Blinking distributes the solution across the eye. Lacrimal solution contains water and salts, plus antibodies and antibacterial enzymes.

6. lacrimal canals - look for two tiny red spots on the medial margin of the eyelid. These are the openings for the lacrimal canals, which collect and drain lacrimal solution after it has washed across the eye surface. The fluid drains through a series of passages, eventually reaching the nasolacrimal ducts in the lacrjmal bones. From there the fluid drains into the nasal cavities and into the nose and throat. This is why your nose runs when you cry.

7. extrinsic eye muscles - are attached to the outer surface of the eye (within the orbit or eye socket, and therefore not visible in an intact face). Six long skeletal muscles control the movement of the eye within the orbit. They are also essential for coordinating the focus between the Ovo eyes. Excessive use of alcohol may cause these muscles to relax or temporarily weaken, producing the "double vision" of intoxication.

Internal anatomy:

Now use the eye model and illustrations in the text or other sources to find and identify the

8. fibrous tunic — name for the covering or outer surface of the eye. The fibrous tunic is divided into two regions

9. sclera - the white of the eye

10. cornea - the transparent covering over the iris and pupil. Some of the models have a cornea and some don't. Look at your lab partner's eye from the side and you will see a structure bulging slightly from the anterior surface, forming a clear dome over the front of the eye.

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11. anterior chamber - the space between the cornea and the iris & pupil

12. iris — the visibly colored portion of the eye. The iris is made of two layers of smooth muscle and bundles of elastic fibers, which function to open and close the pupil.

13. pupil — the central opening of the eye. Light passes through the pupil into the interior portions of the eye.

14. lens - a clear disc of tightly packed crystallin proteins. As light passes through the lens the light waves are bent and tightly focused.

15. suspensory ligaments — on the inner surface of the iris you will see thin, radiating lines. These represent the ligaments that attach the lens to the ciliary muscles.

16. ciliary muscles — smooth muscles of the iris. By contracting and relaxing the muscles pull on the suspensory ligaments and change the shape of the lens. This in turn changes how light passes through the lens and alters the focus.

17. posterior cavity — the large space inside the eyeball behind the iris.

18. retina - also called the sensory tunic, this is the inside surface lining the posterior cavity. The retina contains hundreds of millions of photoreceptors, cells that are sensitive to and respond to light. -mese are microscopic and are not represented on most eye models.

19. cones - photoreceptors for bright light and color vision. Each cone cell contains a colored compound called a visual pigment or iodopsin. We have three types of cones, with three different jodopsins; one responds to blue light (420 nm wavelength), one responds to green light (530 nm) and the third type responds to red light (560 nm).

20. rods — photoreceptors for dim light. Each rod cell contains a pigment called rhodopsin which is purple in color. Rods are active in dim light but provide no sense of color, which is why your night vision tends to be in shades of gray.

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21. macula lutea - Latin for "yellow spot," this is an extremely small region on the posterior portion of the retina. This region contains a dense concentration of cones, and very few rods.

22. fovea centralis - a tiny depression or pit in the middle of the macula lutea, packed with cone photoreceptors. Light passing through the lens js focused to fall mostly on the fovea centralis. Further away from the macula lutea the concentration of cones decreases and the concentration of rods increases. In dim light you can see more detail with your peripheral vision than you can when looking directly at something.

When light falls on a photoreceptor, chemical changes in the visual pigments generate graded potentials jn the cell membrane. These graded potentials affect nearby neural cells in the retina, which then generate and propagate action potentials along axons in the retina.

23. optic disc — the "blind spot" of the eye. Here there are no photoreceptors. Axons of the neural cells merge and collect in this area, forming bundles that exit the eye as the optic nerve.

24. optic nerve - on the rear of the eye model you can see the optic nerve emerging. Sensory action potentials will be taken to the brain along this nerve.

The Ear

External anatomy:

A. auricle or pinna — the fleshy outer portion of the ear. The auricle is composed of elastic cartilage and covered with thin skin.

B. helix - the shell-shaped rim of the auricle.

C. lobule — the dangling "ear lobe" of the auricle.

Many animals have the ability to alter the position of their auricles using extrinsic ear muscles attached to the skull. Humans have the same muscles,

but with a few exceptions, most adults cannot alter the position of their auricles.

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D. external auditory canal or external auditory meatus — the passage from the outside of the body to the internal structures. Sound waves will pass through this canal toward the tympanic membrane and the middle ear structures.

You can use the otoscope to look into the external auditory canal.

E. ceruminous glands - the skin of the external auditory canal contains modified sweat glands. These produce a waxy secretion called cerumen or "earwax." In most people cerumen is a yellowish-brown color, but in some Asians it is gray. Fresh cerumen is sticky and traps dust and other particles. It also contains some insect-repellent chemicals. As cerumen dries, it separates from the skin and, usually, is slowly worked to the outside by motions of chewing, talking and swallowing. In some people, most often children, cerumen may become compacted and collects in the external auditory canal, blocking sound waves and impairing hearing.

F. tympanic membrane - a thin connective tissue membrane dividing the outer ear from the middle ear. The "eardrum." Sound waves passing down the external auditory canal hit the tympanic membrane and cause it to flex and vibrate.

Internal anatomy:

You should now turn your attention to the ear models, as well as the illustrations in your text or other sources.

Middle Ear

G. tympanic cavity - another name for the middle ear

H. ossicles - the three bones of the middle ear. Closest to the tympanic membrane is the

I. malleus (Latin for "hammer") - when sound waves hit the tympanic membrane, the membrane flexes inward and presses on the malleus.

J. incus (Latin for "anvil") — when the malleus moves, it strikes the second ossicle bone; the incus.

K. stapes (Latin for "stirrup") — when the incus moves, it in turn strikes the stapes bone. In this way the sound wave is transmitted through the middle ear to the inner ear.

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L. eustachian tube - also called the auditory tube or the pharyngotympanic tube. This passage allows air to pass between the middle ear and the oral cavity, keeping air pressure equal on both sides of the tympanic membrane. Sometimes when you swallow one or both of your ears will "pop" as the air pressure changes and the tympanic membrane flexes.

Inner ear:

The inner ear is also called the labyrinth because of its complicated and confusing three-dimensional shape. In most models the entire inner ear lifts out as a single piece. There are three areas or sections to the inner ear, the cochlea, the vestibule, and the semicircular canals.

M. cochlea - the organ for the perception of sound. This spiral-shaped bony structure is named for its resemblance to a snail (conch) shell. On some models the cochlea can be opened to show the three parallel chambers inside. Inside the cochlea is a fluid, called pecJympb, or cochlear fluid, which flows around the spiral chambers.

N. oval window - the stapes bone is attached to the opening into the inner ear called the oval window, also called the vestibular window. On the models the opening is completely covered by the stapes. When the stapes is struck by the incus (struck by the malleus, pressed by the tympanic membrane) the stapes pushes in onto the oval window and sets the perilymph in motion. As the perilymph moves it flows across tiny hair cells lining the cochlear chambers. The stiff cilia projecting from these cells are bent by the moving perilymph. When the cilia are bent, they either depolarize or hyperpolarize, depending on the direction of motion. Enough depolarization causes action potentials, which are sent along axons in the cochlear chambers to the cochlear nerve.

O. round window - also called the cochlear window. This tiny opening is covered with a thin connective tissue membrane. When the stapes presses on the perilymph at the oval window, the fluid will flow around the spiral cochlear chambers toward the round window. The membrane over the round window bulges outward, relieving the pressure in the cochlea.

P. vestibulocochlear nerve - also called the auditory nerve. This nerve is composed partly of the cochlear nerve, carrying action potentials from

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the cochlea, and the vestibular nerve carrying action potentials from the other portions of the inner ear.

Q vestibule — contains the structures for the perception of static equilibrium, the ability to sense up and down. Inside the vestibule is a compartment called the utricle. Like the cochlea, the vestibule and utricle are lined with hair cells and filled with perilymph fluid. In addition the utricle contains a thick sheet of jelly-like material called the otolithic membrane. Embedded in the otolithic membrane are many tiny stone-like calcium deposits called otoliths. These make the otolithic membrane very heavy, so it will slide and settle to the bottom of the utricle. The membrane presses on the hair cells, which generate a steady stream of action potentials. If you tip your head to the side, the otolithic membrane slides onto the new 'down' position, and presses on another set of hair cells. These then generate action potentials and signal the new up and down orientation.

Q. semicircular canals — these round structures connect to the vestibule and produce the sensation of dynamic equilibrium. This is what we think of as "balance," as well as the perception of motion, in particular the angular and rotational motions of the head. Although they are called semicircular, notice that each canal actually forms about 2/3 of a circle. When your head moves, the perilymph fluid inside the semicircular canals moves also. As the fluid flows around the canal, it brushes against the cilia of the hair cells, and the cells produce action potentials. The semicircular canals are most sensitive to rotational motion, such as when you twirl around in a circle. When you stop twirling, the fluid is still in motion, producing the sensation that you are still moving, or that the world is spinning around you. Action potentials from the semicircular canals and the utricle pass through axons that merge to become the vestibular nerve, which in turn merges with the cochlear nerve to become the vestibulocochlear nerve or auditory nerve.

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EXERCISE FIVE: The Human BrainObjective: To learn the names, locations and some functions of selected parts of the human brain.

Materials: Human brain models and illustrations from textbook.

Students will work individually or in groups.

Procedure

Use the materials provided to learn the names, locations and brief descriptions of functions of the parts of the brain listed below. The numbers jn parentheses refer to the Denoyer-Geppert Giant Brain models. The colors and numbers will assist you in locating some of the specific regions or areas, but please do not memorize them — real brains don't have bright colors or numbers on them!

I. Definitions. Knowing the definitions of the following terms will help in your study:

a. gyrus — a convoluted ridge on the cerebral cortex from the Greek for "twisted." A gyro sandwich is twisted in the bread.

b. sulcus — a shallow groove between two gyri.

c. hemisphere — one half of a spherical structure, such as one half of the cerebrum or one half of the cerebellum.

d. ventricle — a fluid-filled cavity

e. gray matter — portions of the central nervous system composed primarily of cell bodies and unmyelinated axons. In life this tissue is a dingy gray in appearance.

f. white matter — portions of the central nervous system composed primarily of myelinated axons. In life this tissue is a glossy white in appearance.

g. commissure — white matter fibers that connect hemispheres.

Il. Structures to IdentifyObserve the intact brain model. Gently lift the model and turn it so it is in an upright (anatomical) position. Most of what you are seeing is the cerebrum, the largest part of the human brain. The cerebrum is divided into right and left cerebral hemispheres by the deep longitudinal fissure running down the mid-line of the brain.

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1. Cerebrum

2. cerebral hemisphere

3. longitudinal fissure

4. cerebral cortex - the outer layer of gray matter of the cerebrum. Remove the front piece of the right cerebral hemisphere to see the division between gray matter of the cortex (painted a bright color on the model) and the deeper white matter (white) of the cerebrum.

The surface of the cerebral cortex is thrown into numerous ridges and valleys, the gyri and sulci. The folds form five lobes of the cerebral cortex:

5. frontal lobe (2) — reason, speech, abstract thinking, voluntary' motor activity and perception of odor

6. parietal lobe (4) — body imaging, taste and understanding speech

7. temporal lobe (3) - perception of sound and odors, memory and emotion

8. occipital lobe (5) — sight, memory

9. insula (86) buried beneath the temporal lobe - plays a role in taste and understanding speech

The gyri and sulci of the cortex can be useful landmarks for locating functional regions of the brain.

10. central sulcus (20) — divides the frontal lobe from the parietal

11. anterior central gyrus or pre-central gyrus (10) - primary motor area of the cortex, controls voluntary movement of most skeletal muscle

12. posterior central gyrus or post-central gyrus (11) - primary somatosensory area of the cortex, integrates information about touch, pressure and position

13. lateral sulcus or Sylvian fissure (28) — divides temporal lobe from parietal and frontal lobes

The central nervous system begins in the embryo as a hollow, fluid-filled tube. Remnants of that embryonic structure persist as cavities in the brain and spinal cord filled with cerebrospinal fluid.

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14. lateral ventricles (88 & 89) — ventricles one and two, one in each cerebral hemisphere. The structures curve out and down from the midline and are difficult to represent in models. Gently remove the brainstem from the right hemisphere to see the cavity more clearly

15. third ventricle (113) -a shallow depression around the thalamus in the midbrain

16. cerebral aqueduct or Sylvian aqueduct (57) - a passage for cerebrospinal fluid between the third and fourth ventricle

Aqueducts were large stone and brick systems built by the Romans to bring water from the mountains to the city.

17. fourth ventricle (59) - a wedge-shaped space between the cerebellum and the brain stem. At the inferior end the fourth ventricle connects to the central canal of the spinal cord

18. corpus callosum (41, 42, 43) - a large commisure connecting the right and left cerebral hemispheres

19. fornix (45) — a smaller commisure connecting regions of the limbicsystem The limbic system is a group of structures, some in the cerebrum and some in the thalamus and hypothalamus. These areas produce emotion and control the physical expression of emotion, such as facial expressions.

20. Diencephalon structures

21. thalamus (47, 49, 109) - two egg-shaped masses of gray matter virtually in the center of the brain, held together by the intermediate mass of the thalamus. The thalamus processes and integrates sensory information, sorts and edits what is sent to the cerebral cortex for conscious perception

22. hypothalamus (not numbered) - this triangular region is inferior and somewhat anterior to the thalamus. Find #52 and #68 — the hypothalamus is the region between the numbers. The hypothalamus controls autonomic motor functions, regulates body temperature, and regulates many primitive drives and emotions such as thirst, hunger, sleep, pleasure, pain, fear and rage.

23. mammillary bodies (69) — two "breast-shaped" bulges on the inferior surface of the hypothalamus. These integrate olfactory (smell) sensory information

24. infundibulum (72) - the stalk of the hypothalamus that connects to the pituitary gland

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25. pituitary gland (115) also called the hypophysis — a major gland of the endocrine system, secretes several hormones including growth hormone and oxytocin

26. pineal gland or pineal body (54) - participates in regulation of sleep wake cycle by secreting melatonin (makes you sleepy)

27. Midbrain structures

28. corpora quadrigemina (56, 100, 101, 107, 108) - four C'quad") rounded protrusions on the posterior of the midbrain

29. superior quadrigeminal bodies (100, 107) - coordinate visual reflex movements of the eyes when tracking or following a moving object

30. inferior quadrigeminal bodies (101, 108) - coordinate auditory reflexes, such as tilting the head toward an unexpected sound

31. Cerebellum (6) - Once considered mostly a processing center for unconscious or subconscious motor activity, recent studies indicate the cerebellum also pafticipates in cognitive functions such as language and problem solving, in particular predicting sequences or patterns.

32. cerebellar hemisphere (6)

33. vermis (62 & 130) — connects the two cerebellar hemispheres. This structure may be easier to see on life-size models. Vermis is Latin for "worm." Vermicelli is pasta that looks like a plate of worms.

34. arbor vitae (61) - the white matter of the cerebellum. Arbor vitae is Latin for "tree of life." Notice the highly branched arrangement of the white matter.

35. Pons (65) — this area integrates and coordinates activity of the cerebral motor areas and the cerebellum. With the medulla oblongata the pons also regulates respiration

36. Medulla oblongata (63) - also called just the "medulla." Contains regulatory centers for respiration and cardiac function, as well as vomiting, hiccupping, swallowing, coughing and sneezing reflex centers. Coordinates activity with the hypothalamus

The medulla ends and the true spinal cord begins as the brain stem narrows and passes through the foramen magnum of the skull.

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Nerves are bundles of axons in the peripheral nervous system. Spinal nerves are connected to the spinal cord. Cranial nerves are connected to the brain.Sensory nerves contain only the axons of sensory, or afferent, neurons. Motor nerves contain only the axons of motor, or efferent, neurons. Mixed nerves contain axons of both sensory and motor neurons. All spinal nerves are mixed nerves, but some of the cranial nerves are more specialized.

Cranial nerves are designated by Roman numerals from the anterior to the most posterior. They all originate/terminate on the inferior surface of the brain. Notice that each is actually a pair of nerves, one on each side of the midline of the brain.

I. olfactory nerve (92 & I) - sensory nerve, carries information about sense of smell. Remember the olfactory foramina in the skull?

Il. optic (112 & Il) - sensory nerve, carries impulses from the retinas of the eyes to the visual areas of the occipital lobe.Notice that the optic nerves branch and cross at the optic chiasma (53). The optic chiasma is a major landmark of the brain, and functionally allows both sides of the brain to receive visual information from both eyes. Chiasm is Greek for crossed lines

Ill. oculomotor (114 & Ill) - motor nerve that controls four muscle groups of the eyeball in its socket, and some of the muscles inside the eye attached to the lens and pupil

IV. trochlear (116 & IV) — motor nerve that controls some of the muscles of the eye socket. Trochlea in Latin means spool or pulley. See the illustrations of the eye muscles in your text to see the connection.

V. trigeminal (117 & V) - mixed nerve. Sensory components for forehead and eyelids, teeth, palate and gums. Motor components for chewing

VI. abducens (118 & VI) - motor nerve that controls lateral movements of the eyeball in the socket

VII. facial (119 & VII) - a mixed nerve. Sensory components for taste. Motor components for some facial muscles and expressions, and tear and salivary gland secretions

VIII.auditory or vestibulocochlear (120 & VIII) - also called the acoustic nerve, a sensory nerve that carries information from the semicircular canals of the inner ear for balance, and the cochlea of the inner ear for hearing

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glossopharyngeal (121 & — a mixed nerve. Sensory components for tongue and lining of pharynx. Motor component for muscles in pharynx involved in swallowing

X. vagus (122 & X) — a mixed nerve. Sensory information for pharynx, larynx, esophagus and organs of the thorax. Motor functions on muscles of speech, swallowing and the heart.

XI. spinal accessory or accessory (123 & - motor nerve, controls some of the muscles of the neck

XII. hypoglossal (124 & - motor nerve, stimulates muscles of the tongue for speech, chewing and swallowing

Over the years anatomy students have developed a number of mnemonic devices to remember the cranial nerves. Here's a few:

(Read down)

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