Gapcom 4/10 Cell Injury (X)

Front 1

what are a cells responses to an injurious stimulus

Back 1

if its reversible cell injury it has not passed the point of irreversibility, however, if not treated, can lead to necrosis. if the injury sustained is bad enough, the cell could just enter apoptosis

Front 2

differentiate hypoxemia and hypoxia

Back 2

-hypoxemia is low levels of oxygen in blood (ex. anemia)
-hypoxia is low levels of oxygen in tissues

Front 3

what are characteristics of cell injury

Back 3

1. integrity of cell membranes
2. aerobic respiration - oxidative phosphorylation and ATP
3. synthesis of enzymes & proteins
4. preservation of genetic apparatus of the cell

Front 4

define ischemia. anoxia

Back 4

insufficient blood supply bc occlusion of artery or vein.
-total loss of oxygen supply

Front 5

what are the two types of morphology in injured cells

Back 5

swells bc of Na+ channel into cell.
1. reversible injury - cell swelling leading to hydropic change or vacuolar degeneration
2. irreversible injury - cell injury leading to necrosis (nuclear pyknosis [condensation of chromatin] followed by karyorrhexis and karyolysis [dissolves away])
is irreversible if there is a rupture of cell membrane or lysosomes

Front 6

what are the ultrastructural features of cell injury?

Back 6

1. cell swelling
2. cytoplasmic blebs
3. distortion of microvilli
4. mitochondrial swelling
5. dilatation of ER

Front 7

define karyorrhexis

Back 7

Rupture of the nucleus, releasing disintegrated chromatin.

Front 8

list the types of necrosis

Back 8

1. coagulative
2. liquefaction
3. fat
4. caseous
5. fibrinoid
6. gangrenous

Front 9

define coagulative necresis and what can cause it?

Back 9

-dissolution of nucleus with preservation cellular shape and tissue architecture.
-ischemic injury, ionizing radiation, viruses, chemicals
- coagulation (denaturation) of cell proteins

Front 10

define: autophagy

Back 10

Digestion of the cell's own organelles

Front 11

define: liquefaction necrosis, and give ex.

Back 11

hydrolytic enzymes cause autolysis and heterolysis. ex. abscess (often in lung)and brain infarct (stroke)

Front 12

define: fat necrosis, and give ex.

Back 12

destruction of adipose tissue due to action of lipases. ex. pancreatitis, pancreatic tumor, salivary gland (trauma or infection), breast (trauma).

Front 13

with coagulative necrosis in the kidney, what order will the areas be damaged by ischemia

Back 13

1. PCT
2. glomeruli
3. collecting duct

Front 14

define: caseous necrosis

Back 14

combination of coagulative and liquefaction necrosis. primarily foudn in the center of tubercles. inability to digest and remove material from center of granuloma. sharp border btw granuloma. cottage cheese consistency, ex tb in lungs

Front 15

define: fibrinoid necrosis

Back 15

necrotic tissue due to immunologic reaction. usu seen in blood vessels with deposition of complement and antibodies in vessel wall. seen as bright red in stain indicating dead tissue, complement and Ab.

Front 16

define: gangrenous necrosis

Back 16

coagulative necrosis with secondary bacteria infection leading to liquefaction.

Front 17

differentiate wet and dry gangrene

Back 17

dry - coagulative necrosis is the predominant pattern
wet - liquefactive process is the dominant pattern.

Front 18

define apoptosis

Back 18

programmed cell death

Front 19

give ex. of physiologic apoptosis

Back 19

1. embryogenesis (loss webbed fingers)
2. hormone-dependent involution - menstrual cycle, lactating breast
3. deletion of proliferating cells - intestinal crypt epithelia
4. selective death of immunocytes - developing thymus

Front 20

give ex. of pathologic apoptosis

Back 20

1. viral dx leading to cell death (acidophil or councilman bodies, viral hepatitis)
2. pathologic atrophy - prostatic atrophy after castration
3. duct obstruction - cells self destruct
4. T8 (cytotoxic) lymphocytes - graft-versus-host dx
5. injurious agents - anticancer drugs, radiation

Front 21

mechanisms of apoptosis

Back 21

1. activation of endonucleases
2. cytoskeleton disruption by proteases
3. cytoplasmic protein cross-linking by transglutaminase
4. cell surface changes leading to phagocytosis

Front 22

compare morphologic characteristics of apoptosis to necrosis

Back 22

A - general cell shrinkage, chromatin condensation, bleb formation & apoptotic bodies, phagocytosis, and lack of an inflammatory reaction
N - swelling cells, water, chromatin condensation, blebs, then blow up, inflammatory reaction clean up mess

Front 23

two pathologic techniques to determine if cell is undergoing apoptosis or necrosis

Back 23

1. histo stain - apoptotic bodies have no inflammatory rxn around them, as compared to a necrotic breakdown.
2. run DNA ladder with endonucleases - if apoptosis, you will see specific sites with endonucleases, whereas with necrosis, you will see a smear of dif size DNA pieces.

Front 24

intracellular accumulations can occur with which compounds?

Back 24

lipids, proteins, glycogen, complex lipids and carbohydrates, and pigments

Front 25

what types of fatty change can occur?

Back 25

histologically - push nucleus to side, and stain red
1. lipid in parenchyma cells (ex. alcoholic fatty liver)
2. lipid in macrophages (ex. xanthomas, foam cells)
3. stromal infiltration of fat (ex. fat in myocardium)

Front 26

give examples of exogenous and endogenous pigments

Back 26

exogenous: carbon (anthracosis), tattooing, natural substances (B carotene), poisons - lead (pica)
endogenous pigments - lipofuscin, melanin, hemosiderin