Cell Death

Question 1

necrosis

Answer 1

*cell death by injury
*characterized by loss of membrane integrity, enzymatic digestion of cells, host reaction/response
*ALWAYS PATHOLOGIC
*affects LARGE fields of cells

Question 2

nuclei changes associated with cell death

Answer 2

*pyknosis
*karyorrhexis
*karyolysis

Question 3

pyknosis

Answer 3

nuclear shrinkage, condensed chromatin
*indicates cell death

Question 4

karyorrhexis

Answer 4

nuclear fragmentation
*indicates cell death

Question 5

karyolysis

Answer 5

faded chromatin
*indicates cell death

Question 6

coagulative necrosis - overview

Answer 6

*hypoxic cell death in tissue (all except brain)
*most common type of necrosis
*caused by ischemic necrosis (cutoff of blood supply)

Question 7

coagulative necrosis - pathologic features

Answer 7

*“GHOST ARCHITECTURE” - preserved structural outline of tissues (can still identify the tissue)
*acids denature proteins
*ex. = myocardial infarction

Question 8

liquefactive necrosis - overview

Answer 8

*enzymatic liquefaction of dead cells/tissue
*caused by ischemic necrosis in brain, pancreatitis (enzymatic digestion), or suppurative infection

Question 9

liquefactive necrosis - pathologic features

Answer 9

*cavitations with liquid centers
*NO ghost architected
*contains cell debris and inflammatory cells

Question 10

caseous necrosis - disease that causes

Answer 10

TUBERCULOSIS

Question 11

caseous necrosis - pathologic features

Answer 11

*caseous - “cheese-like” consistency
*granulomatous inflammation
*obliterates structure, resulting in cavitation

Question 12

gangrenous necrosis - overview

Answer 12

*sudden vascular occlusion / blood supply interruption of lower extremities or bowel

Question 13

dry gangrene

Answer 13

*presents as coagulative ischemic necrosis

Question 14

wet gangrene

Answer 14

*secondary complication with bacterial/infective heterolysis

Question 15

gas gangrene

Answer 15

*Clostridium perfringens myconecrosis produces GAS in tissues to cause gangrene
*bubbles up

Question 16

fibrinoid necrosis - overview

Answer 16

*vascular necrosis with “fibrin-like” deposition
*associated with autoimmune vasculitis

Question 17

fat necrosis - overview

Answer 17

*enzymatic proteolytic/lipolytic digestion
*caused by trauma to adipose tissues or pancreatitis

Question 18

fat necrosis - pathologic features

Answer 18

*foamy appearing macrophages
*fat saponification (chalky fats)

Question 19

apoptosis

Answer 19

*cell death by suicide
*tightly controlled programmed cell death program
*affects SINGLE cells
*LACK of inflammation
*could be physiologic or pathologic

Question 20

series of changes in apoptosis

Answer 20

1. cytoplasmic shrinkage
2. nuclear changes (pyknosis, etc)
3. apoptotic bodies
4. phagocytosis of the apoptotic bodies

Question 21

biochemical features of apoptosis

Answer 21

1. caspase cascade
2. activation of transglutaminases
3. activation of endonucleases
4. rapid phagocytosis

Question 22

mitochondrial pathway for initiation of apoptosis

Answer 22

*non-receptor mediated
*injury to the mitochondria stimulates apoptosis through:
1. INACTIVATION of BCL-2 (an anti-apoptotic signal)
2. stimulation of BAX/BAK
3. release of cytochrome C
4. activation of caspase cascade

Question 23

death receptor pathway for initiation of apoptosis

Answer 23

*plasma membrane “death receptor” mediated
1. T cell expression of FasL binds to FAS, forming a trimer (death domain)
2. activation of caspase cascade

Question 24

cytotoxic pathway for initiation of apoptosis

Answer 24

1. CD8+ cytotoxic T cells secrete perforin
2. granzyme B goes through the pore and into target cell
3. activation of caspase cascade

Question 25

examples of physiologic apoptosis

Answer 25

*involution (ex. get rid of yolk sac after embryogenesis; lactating breast returning to normal)
*replace cells for maintenance (ex. GI tract)
*destroy cells that represent a threat (ex. virally infected cells, cells with DNA damage)

Question 26

apoptosis and cancer

Answer 26

*some viruses (HPV and EBV) produce oncogenes that inhibit or evade apoptosis