Introduction to Introduction to PathologyPathology

Chapter 1Chapter 1

Heather Johnson, A.S., R.T. Heather Johnson, A.S., R.T. (R)(R)

Good to know…Good to know…

you need to have a good you need to have a good understanding of normal anatomy in understanding of normal anatomy in order to differentiate it from order to differentiate it from pathologypathology

remember that medical terminology remember that medical terminology class way back in first semester?class way back in first semester?

Why take a pathology class?Why take a pathology class?

““We’re not supposed to read the x We’re not supposed to read the x rays!”rays!”

A basic understanding of pathology A basic understanding of pathology helps you do your job better.helps you do your job better.

Why take a pathology class?Why take a pathology class?

better care for your patient – more better care for your patient – more careful positioning, alternative careful positioning, alternative positioning, care to protect positioning, care to protect immunocompromised patient, immunocompromised patient, protect yourself, more understandingprotect yourself, more understanding

change in routine projections to change in routine projections to make a subtle pathology stand outmake a subtle pathology stand out

change in techniquechange in technique

DiseaseDisease

PathologyPathology is defined as: the study of is defined as: the study of disease that can cause abnormalities disease that can cause abnormalities in body structure or functionin body structure or function

1.1. can be hereditarycan be hereditary

2.2. can be the result of previous injury, can be the result of previous injury, infection, vascular or metabolic infection, vascular or metabolic abnormalityabnormality

3.3. presents as signs or symptomspresents as signs or symptoms

iatrogeniciatrogenic – pathology caused by a – pathology caused by a physician and their treatmentphysician and their treatment

nosocomial infectionnosocomial infection – hospital- – hospital-acquiredacquired

community acquired infectioncommunity acquired infection – – acquired outside of a health care acquired outside of a health care facilityfacility

idiopathicidiopathic – cause is unknown – cause is unknown

InflammationInflammation

swellingswellingbody’s response to injury, can be body’s response to injury, can be

anywhere in / on the body, but is anywhere in / on the body, but is often localizedoften localized

process of inflammation:process of inflammation:

1.1. increased blood flow and vascular increased blood flow and vascular permeability (capillaries allow for more permeability (capillaries allow for more permeation of exudate)permeation of exudate)

2.2. white blood cells migrate to injured white blood cells migrate to injured tissuetissue

3.3. injured (dead) cells are eaten injured (dead) cells are eaten (phagocytosis)…yuk(phagocytosis)…yuk

4.4. proliferation of normal parenchymal cells proliferation of normal parenchymal cells and granulation (scar) tissueand granulation (scar) tissue

some tissues cannot heal by some tissues cannot heal by regeneration – heart, damaged area regeneration – heart, damaged area replaced by scarreplaced by scar

some partially heal, partially scar – some partially heal, partially scar – cirrhosis of liver, mix of regenerated cirrhosis of liver, mix of regenerated cells and scar tissuecells and scar tissue

5 signs of inflammation5 signs of inflammation

1.1. rubor (redness)rubor (redness)

2.2. calor (heat)calor (heat)

3.3. tumor (swelling)tumor (swelling)

4.4. dolor (pain)dolor (pain)

5.5. loss of functionloss of function

EdemaEdema

accumulation of fluid in tissue or accumulation of fluid in tissue or body cavities in abnormal amounts body cavities in abnormal amounts or for a prolonged amount of timeor for a prolonged amount of time

can be localized (inflammatory can be localized (inflammatory reaction) or generalized reaction) or generalized (subcutaneous accumulation (subcutaneous accumulation throughout the body)throughout the body)

localized edemalocalized edema

area of inury, area of blocked area of inury, area of blocked lymphatic drainagelymphatic drainage

filariasis – parasitic worm causing filariasis – parasitic worm causing lymphatic obstructionlymphatic obstruction

Elephantiasis (filariasis)Elephantiasis (filariasis)

generalized edemageneralized edema

fluid accumulation over entire body fluid accumulation over entire body or regionsor regions

CHF, cirrhosis of the liver, renal CHF, cirrhosis of the liver, renal diseasedisease

ambulatory patients – accumulates in ambulatory patients – accumulates in distal lower extremitiesdistal lower extremities

sedentary patients – accumulates in sedentary patients – accumulates in back and lungsback and lungs

ischemiaischemia

interference of an organ or tissue’s blood interference of an organ or tissue’s blood supplysupply

caused by narrowing of arterial vessels, most caused by narrowing of arterial vessels, most often from atherosclerosis, thrombus/embolus; often from atherosclerosis, thrombus/embolus; less often external force (post-traumatic less often external force (post-traumatic swelling, unintentional mechanism)swelling, unintentional mechanism)

less dangerous when occlusion is slow-growing less dangerous when occlusion is slow-growing and in a healthy patientand in a healthy patient

more dangerous when it occurs rapidly, or more dangerous when it occurs rapidly, or happens in patients with anemiahappens in patients with anemia

incidence increases after a patient has surgeryincidence increases after a patient has surgery

infarctinfarct

localized necrosis (death) of tissue or localized necrosis (death) of tissue or an organ due to venous or arterial an organ due to venous or arterial ischemiaischemia

most common form are myocardial most common form are myocardial and pulmonaryand pulmonary

can also lead to gangrenecan also lead to gangrene

hemorrhagehemorrhage

rupture of a larger artery or veinrupture of a larger artery or veinmay be caused by trauma, may be caused by trauma,

atherosclerosis, or erosion of a vessel atherosclerosis, or erosion of a vessel wall (cancer)wall (cancer)

accumulations of blood trapped accumulations of blood trapped within the body is called a within the body is called a hematomahematoma

ecchymosisecchymosis – subcutaneous – subcutaneous hematoma (bruise)hematoma (bruise)

facts:facts:

1.1. a patient can lose up to 20% of a patient can lose up to 20% of their total blood supply with little their total blood supply with little clinical significanceclinical significance

2.2. urgency of hemorrhage depends on urgency of hemorrhage depends on location in the bodylocation in the body

alterations in cell growthalterations in cell growth

atrophyatrophy- the reduction in size or - the reduction in size or number of cells in organ or tissue; number of cells in organ or tissue; results in decreased function; disuse results in decreased function; disuse or pathologicor pathologic

hypertrophyhypertrophy – increase in – increase in sizesize of cells of cells due to increased use; ex. musclesdue to increased use; ex. muscles

hyperplasiahyperplasia – increase – increase number number of of cells; ex. granulation tissuecells; ex. granulation tissue

dysplasiadysplasia – loss of cell uniformity due – loss of cell uniformity due to irritation (premalignant)to irritation (premalignant)

Hyperplasia, cortical thickening

neoplasms / oncologyneoplasms / oncology

neoplasianeoplasia – abnormal growth of cells – abnormal growth of cells (tumors)(tumors)

benign tumorsbenign tumors – resemble tissue of – resemble tissue of origin, do not spread to other areas (do origin, do not spread to other areas (do not metastasize); not as dangerous , not metastasize); not as dangerous , but can still cause complicationsbut can still cause complications

malignant tumorsmalignant tumors (cancer) – invade and (cancer) – invade and destroy tissue, spread (metastasize)destroy tissue, spread (metastasize)

carcinomacarcinoma – cancer of epithelial cells – cancer of epithelial cells (mucous linings in body)(mucous linings in body)

sarcomasarcoma – cancer of bone, muscle, and – cancer of bone, muscle, and cartilage, highly malignantcartilage, highly malignant

metastases occur via the lymphatic or metastases occur via the lymphatic or hematogenous systemshematogenous systems

cancer gradingcancer grading – cell’s aggressiveness – cell’s aggressiveness cancer stagingcancer staging – extent of entire body – extent of entire body

involvementinvolvement

hereditary diseaseshereditary diseases

abnormal DNA passed from one abnormal DNA passed from one generation to anothergeneration to another

mutations may occur by enzyme mutations may occur by enzyme mutation, radiation, chemicals, or mutation, radiation, chemicals, or virusesviruses

Right foot image with seven metatarsals and eight digits demonstrating polydactyly

immunity disordersimmunity disorders

most immunity is acquired by exposure most immunity is acquired by exposure to antigens or artificial immunizationsto antigens or artificial immunizations

vaccinevaccine – low dose of dead or – low dose of dead or deactivated viruses that stimulate the deactivated viruses that stimulate the body to produce antibodiesbody to produce antibodies

active immunityactive immunity – when a body forms – when a body forms antibodies due to exposureantibodies due to exposure

passive immunitypassive immunity – a dose of – a dose of preformed antibodies from an animal; preformed antibodies from an animal; acts quickly, but doesn’t stay in bodyacts quickly, but doesn’t stay in body

AIDS / HIVAIDS / HIV

acquired immunodeficiency syndromeacquired immunodeficiency syndromemost commonly affected homosexual most commonly affected homosexual

men, IV drug users, but now rising in men, IV drug users, but now rising in incidence among heterosexual incidence among heterosexual partners, and third world countriespartners, and third world countries

once epidemic amongst hemophiliacsonce epidemic amongst hemophiliacsprimarily affects the lungs, GI tract, primarily affects the lungs, GI tract,

and CNSand CNS

radiographically:radiographically:

1.1. pneumocystis carinii – hazy pneumocystis carinii – hazy infiltrates in lungs, consolidation infiltrates in lungs, consolidation resembling pneumoniaresembling pneumonia

2.2. Kaposi’s sarcoma – nodules in small Kaposi’s sarcoma – nodules in small bowel that invade the lumenbowel that invade the lumen

1-61-6

Kaposi’s sarcoma. Small bowel study shows multiple intramural nodules (predominantly involving the jejunum) that distort the mucosal pattern

1-71-7

Pneumocystis carinii pneumonia. Diffuse bilateral air-space consolidation

treatment:treatment:

1.1. incurableincurable

2.2. symptom managementsymptom management

3.3. lifestyle changes – avoid stress, lifestyle changes – avoid stress, alcohol, drugs, infectionsalcohol, drugs, infections