Ch2 Cell Death EC Flashcards Preview

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Flashcards in Ch2 Cell Death EC Deck (27):
1

Necrosis

Death of groups of cells + inflammation

2

Coagulative necrosis

Preservation of structural outlines

3

Mechanism of coagulative necrosis

Denaturation of enzymes and structural proteins (lactate, heavy metals, ionizing radiation)

Inactivation of intracellular enzymes

4

Microscopic features of coagulative necrosis

Indistinct outlines of cells within dead tissue
Nuclei absent

5

Infarction

Gross manifestation of coagulative necrosis due to sudden occlusion of a vessel

6

Pale (ischemic) infarcts

Dense tissue
(heart, kidney, spleen)

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Hemorrhagic (red) infarcts

Loose tissue
(lung, bowel, testicle)

8

Dry gangrene

Toes in DM is a form of infarction that results from ischemia with coagulation necrosis

9

When is an infarction less likely to occur?

Dual blood supply (lungs)
Collateral circulation (arcade system of superior/inferior mesenteric arteries)
Preexisting disease

10

Mechanism of liquefactive necrosis

Release of lysosomal enzymes by necrotic cells or by the release of hydrolytic enzymes by neutrophils

11

Examples of liquefactive necrosis

Cerebral infarction (via hydrolytic enzymes from neuroglial cells)
Abscess in bacterial infection (via hydrolytic enzymes released by neutrophils)

12

Wet gangrene

Predominantly liquefactive necrosis
Dry gangrene + superimposed anaerobic infection (C. perfringens)

13

Mechanism of caseous necrosis

Produced by lipid from cells walls of mycobacterium and fungi after immune destruction by macrophages in granulomas

*other granulomas as noncaseating because they lack excessive amounts of lipid*

14

Gummatous necrosis

Type of coagulation necrosis
Associated with spirochetal disease (syphilis)
Hypersensitivity directed against spirochetes

15

Mechanism of enzymatic fat necrosis

Activation of pancreatic lipase causes hydrolysis of TGs in fat cells
Calcium combines with fatty acids via saponification

16

Traumatic fat necrosis

Necrosis in fatty tissue as a result of trauma
Non-enzymatic (unlike pancreas)

17

Fibrinoid necrosis

Necrosis that may occur in small muscular arteries, arterioles, venules, glomerular capillaries, valve leaflets, myocardium, and subcutaneous tissue

18

Mechanism of fibrinoid necrosis

Deposition of pink-staining proteinaceous material in damaged tissue
Necrosis of immune-mediated disease

19

Extrinsic apoptosis pathway (death receptor pathway)

TNFR1 binds TNF-alpha
Fas-R binds Fas-Ligand
(Perforin and granzyme B in immune cells)

Activation of initiator caspases (8&10)
Activation of effector caspases
~Protease destroys cytoskeleton
~Endonuclease causes pyknosis of nucleus

20

Intrinsic apoptosis pathway (mitochondrial pathway)

BCL-2 stabilizes cytochrome c in mito. membrane (anti-apoptotic)
BAX/BAK form channels in mito. membrane (pro-apoptotic)
Cytochrome C complexes with another protein activating initiator caspase 9
Activation of effector caspases
~Protease destroys cytoskeleton
~Endonuclease causes pyknosis of nucleus

21

Microscopic appearance of apoptotic cells

Deeply eosinophilic
Nucleus pyknotic, fragmented, or absent
Minimal inflammation

22

Pyroptosis

Proinflammatory cell death using caspase-1

Monocyte cell destruction of Salmonella, Shigella, Legionella

23

What are some examples of pathologic activation of caspase-1?

MI
Neurodegenerative disease
IBD
Cerebral ischemia
Endotoxic shock

24

Aspartate aminotransferase (AST) diagnostic use

Marker of diffuse liver cell necrosis
Mitochondrial enzyme preferentially increased in alcohol-induced liver disease

25

Alanine aminotransferase (ALT) diagnostic use

Marker of diffuse liver cell necrosis (ie viral hepatitis)
More specific for liver cell necrosis than AST

26

Creatine kinase MB (CK-MB) diagnostic use

Isoenzyme increased in acute MI or myocarditis

27

Amylase and lipase diagnostic use

Marker enzymes for acute pancreatitis
Lipase more specific than amylase (also increased in salivary gland inflammation [mumps])

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