Cellular Adaptation and Cell Necrosis

Question 1

Cell Adaptation

Answer 1

prolonged exposure of cells to adverse or exaggerated normal stimuli

evokes various changes at the level of individual cells, tissues or whole organs

cause removed

• most cells revert to normalcy
• some do not –> detrimental results

Question 2

How Cells Adapt to Change (6)

Answer 2

Atrophy
Hypertrophy
Hyperplasia
Metaplasia
Dysplasia
Anaplasia

Question 3

Atrophy: definition

Answer 3

Decrease in size of a tissue, organ or entire body

physiologic or pathologic

Question 4

Atrophy: physiologic

Answer 4

thymus undergoing involution

ovaries, uterus and breasts after menopause

atrophic bones and muscles in the elderly become thin and prone to fracture

Question 5

Atrophy: pathologic

Answer 5

ischemic organs are typically small (ie: kidneys involved with atherosclerosis)

• testicular atrophy
• alzheimer dementia

Question 6

Hypertrophy: definition

Answer 6

an increase in the size of tissues or organs due to enlargement of individual cells

physiologic or pathologic

Question 7

Hypertrophy: physiologic

Answer 7

enlargement of skeletal muscles in body builders due to weights

Question 8

Hypertrophy: pathologic

Answer 8

heart adapts to increased workload

-concentric hypertrophy of L ventricular muscle mass (HT) is adaptive response to L ventricular pressure overload

Question 9

Hyperplasia: definition

Answer 9

an adaptive increase in the number of cells that can cause enlargement of tissues or organs

Question 10

Hyperplasia: pathologic

Answer 10

endometrial hyperplasia (due to estrogens)

hyperplastic polyps (of the colon or stomach)

hyperplastic prostate (BPH) - inc in size and number of glands and stroma

Question 11

Hyperplasia: physiologic

Answer 11

hypertrophy of the uterine smooth muscle cells during pregnancy is accompanied by hyperplasia

Question 12

Metaplasia: definition

Answer 12

an adaptive change of one cell type for another to suit the environment

reversible

can progress to dysplasia

Question 13

Metaplasia: pathologic

Answer 13

squamous metaplasia of the bronchial epithelium due to smoking

gastric or glandular metaplasia of GE junction in Barrett Esophagus

Question 14

Dysplasia: definition

Answer 14

disordered growth of tissues resulting from chronic irritation or infection

precancerous condition

Question 15

Dysplasia: pathologic

Answer 15

detection of cervical dysplasia (cervical intraepithelial neoplasia) based on pap smears

Question 16

Anaplasia: definition

Answer 16

undifferentiated and uncontrolled growth of cells

aka: malignancy, carcinoma, cancer, neoplasm

Question 17

Anaplasia: pathologic

Answer 17

squamous cell carcinoma of the cervix

cancer of the lung

malignant melanoma

renal cell carcinoma

Question 18

Anaplasia: microscopic hallmarks

Answer 18

1. cellular pleomorphism
2. irregular and hyperchromatic nuclei
3. extremely high nuclear/cytoplasmic ratio
4. large nucleoli
5. large numbers of abnormal mitotic figures

Question 19

Cell Necrosis: definition

Answer 19

the death of cells or groups of cells within a living organism

Question 20

Cell Necrosis v. Autolysis

Answer 20

Necrosis: seen in the living (w/ inflammation)

Autolysis: seen after death

Question 21

Types of Necrosis

Answer 21

coagulative
liquefactive
caseous
fat

Question 22

Coagulative Necrosis: definition

Answer 22

most common form of necrosis

cell proteins are altered or denatured

cell outlines preserved

cytoplasm appears finely granular

Question 23

Coagulative Necrosis

Answer 23

location: solid organs (heart, kidney, spleen, liver)
cause: anoxia
ie: heart tissue undergoing a myocardial infarction

Question 24

Liquefactive Necrosis: definition

Answer 24

process by which dead cells liquify under the influence of certain cell enzymes

tissue becomes soft and gel-like

Question 25

Liquefactive Necrosis

Answer 25

location: brain ie: - brain infarcts (stroke) - bacterial infection - abscesses in the lungs/liver

Question 26

Caseous Necrosis: definition

Answer 26

a form of coagulative necrosis in which a thick, yellowish, cheesy substance forms

Question 27

Caseous Necrosis

Answer 27

location: tuberculosis ie: - Ghon complex (lung granulomas with caseous necrosis inside) - some fungal infections (Histoplasmosis)

Question 28

Fat Necrosis: definition

Answer 28

a specialized form of liquefaction necrosis caused by the action of lipolytic enzymes

Question 29

Fat Necrosis

Answer 29

location: fat tissue (usually around pancreas, also breast) rupture of pancreas --> enzymes released into fat tissue --> fat degradated into glycerol and FFA --> FFA binds with Ca --> soaps formed --> white calcified specks

Question 30

Wet v. Dry Gangrene

Answer 30

Wet: inflammation and secondary liquefaction of coagulated tissue following bacterial infection ie: advanced decubitus ulcers Dry: necrotic tissue dries out - becomes black and mummified

Question 31

Underlying infections contributing to gangrene...

Answer 31

infarction of the intestines or in a limb atherosclerosis diabetes

Question 32

Dystrophic Calcifications: definition

Answer 32

macroscopic deposition of calcium in injured or dead tissues represents an extracellular deposition of Ca from the circulation into dead or dying necrotic tissue

Question 33

Dystrophic Calcifications: examples

Answer 33

1. calcifications in atherosclerotic coronary arteries --> narrow vessels 2. calcifications of mitral or aortic valves --> impeded blood flow (stenosis) 3. calcification around breast cancers 4. infant periventricular calcifications in congenital Toxoplasmosis

Question 34

Metastatic Calcifications: definition

Answer 34

deranged calcium metabolism associated with increased serum calcium levels

Question 35

Metastatic Calcifications: examples

Answer 35

hyperparathyroidism vitamin D toxicity chronic renal failure ``` calcium stone formation in: -gallbladder -kidney -bladder (due to precipitation of salts from solution into tissues) ```