1.3 Cell Death

Question 1

What is the morphological hallmark of cell death?

Answer 1

Loss of the nucleus

Question 2

What is pyknosis?

Answer 2

Shrinkage of the nucleus

Question 3

What is Karyorrhexis?

Answer 3

Breakdown of the nucleus into pieces

Question 4

What is karyolysis?

Answer 4

The complete dissolution of the chromatin of a dying cell due to the enzymatic degradation by endonucleases

Question 5

What are the three major stages of cell death?

Answer 5

1. Pyknosis
2. Karyorrhexis
3. Karyolysis

Question 6

True or false: necrosis is alway pathologic

Answer 6

True

Question 7

What is the major difference between necrosis and apoptosis?

Answer 7

Necrosis is followed by inflammation

Question 8

What, generally, is coagulative necrosis?

Answer 8

Necrotic tissue that retains its shape and firmness d/t preservation of the organ structure and coagulation of cellular proteins

Question 9

What happens to the nucleus with coagulative necrosis?

Answer 9

Disappears

Question 10

Coagulative necrosis can be characteristic of necrosis in any organ, except for which?

Answer 10

Brain

Question 11

What process produces coagulative necrosis?

Answer 11

Ischemic infarction

Question 12

What is the general shape of areas of infarcts?

Answer 12

Wedge shaped

Question 13

What causes a red infarction?

Answer 13

If blood reenters an area of loosely organized tissue that underwent necrosis

Question 14

Why is it essential that CT is loose if a red infarct is to occur?

Answer 14

Needs to be able to hold the blood

Question 15

What occurs with liquefactive necrosis?

Answer 15

Enzymatic lysis of cells and proteins resulting in liquefaction

Question 16

What are the three classic circumstances in which liquefactive necrosis occurs?

Answer 16

• Brain infarction
• Abscesses
• Pancreatitis

Question 17

Why is it that the brain in particular undergoes liquefactive necrosis?

Answer 17

Microglial cells release oxygen radicals and crush the brain tissue like Stalin

Question 18

Why is different about the cells that mediate liquefactive necrosis in abscesses as compared to the brain?

Answer 18

PMNs do it in abscesses

Microglial cells do it in the brain

Question 19

What causes the liquefactive necrosis of the pancreas?

Answer 19

Enzymes of the pancreas digest pancreas

Question 20

What is gangrenous necrosis?

Answer 20

Coagulative necrosis that resembles mummified tissue

Question 21

Where in the body does gangrenous necrosis classically occur (but not the only place)?

Answer 21

Lower limb and GI tract

Question 22

What makes gangrene “wet”?

Answer 22

Superimposed infection on the gangrenous necrosis

Question 23

What is caseous necrosis? What classically causes this type of necrosis?

Answer 23

Combination of coagulative and liquefactive necrosis

Granulomatous inflammation d/t TB or fungal infx

Question 24

What is the gross appearance of caseous necrosis?

Answer 24

Cottage cheese

Question 25

What is the classic gross appearance of fat necrosis? What causes this?

Answer 25

Chalky white appearance d/t Ca deposition

Question 26

What is saponification?

Answer 26

the alkaline hydrolysis of the fatty acid ester--FAs released by trauma or lipase join with Ca

Question 27

What type of necrosis does the pancreas undergo?

Answer 27

Pancreas itself = liquefactive Fat necrosis of the peripancreatic fat

Question 28

What are the two classic regions of the body that undergo fat necrosis?

Answer 28

Peripancreatic fat | Breast trauma

Question 29

What type of cell might be seen with fat necrosis?

Answer 29

Giant cells

Question 30

What are the two general processes of Ca deposition in the body?

Answer 30

- Necrotic tissue become a nidus for Ca deposition | - psammoma bodies

Question 31

What happens to serum Ca levels with dystrophic calcification? Serum phosphate?

Answer 31

Both normal

Question 32

What is metastatic calcification? What are the relative serum Ca and phosphate levels with this?

Answer 32

Increased concentration of Ca and phosphate in the serum pathologically deposit Ca into tissues

Question 33

True or false: metastatic calcification always occurs d/t a cancer somewhere?

Answer 33

False--just means that Ca levels are high. Cancers can however, cause this, but it is not required.

Question 34

What is fibrinoid necrosis?

Answer 34

Necrotic damage to the blood vessel wall from the leakage of proteins from serum

Question 35

What causes the bright pink staining characteristics of fibrinoid necrosis?

Answer 35

Leakage of proteins into vessel wall

Question 36

What are the two major (general) causes of fibrinoid necrosis?

Answer 36

Malignant HTN or vasculitis

Question 37

What causes fibrinoid necrosis of the placenta?

Answer 37

Preeclampsia

Question 38

True or false: apoptosis requires energy

Answer 38

True

Question 39

Does apoptosis involve a single cell, or groups of cells

Answer 39

Either

Question 40

What is the process that causes separation of the fingers during embryogenesis?

Answer 40

Apoptosis

Question 41

What causes the endometrial lining to be shed during menses?

Answer 41

Apoptosis of the endometrial lining

Question 42

Does CD8+ T cell killing cause necrosis or apoptosis?

Answer 42

Apoptosis

Question 43

What are the general morphological changes that occur with apoptosis?

Answer 43

Shrinkage of the cell with intense eosinophilia, and budding off of cell contents

Question 44

What happens to the nucleus with apoptosis?

Answer 44

Nucleus condenses and fragments

Question 45

What happens to the apoptotic bodies that fall off of the cell?

Answer 45

Macrophages eat 'em up

Question 46

What enzymes are the key mediators of apoptosis?

Answer 46

Caspases

Question 47

What is the role of the proteases that caspases activate?

Answer 47

Break down the cell cytoskeleton

Question 48

What is the function of the endonucleases that caspases activate?

Answer 48

Break down DNA

Question 49

What is the key sign of irreversible damage?

Answer 49

membrane damage

Question 50

What is the intrinsic mitochondrial pathway that leads to apoptosis?

Answer 50

Damage of some sort deactivates Bcl2

Question 51

What is the role of Bcl2?

Answer 51

Stabilizes the mitochondrial membrane, to prevent cytochrome C from leaking out and killing the cell

Question 52

What is the receptor that activates the extrinsic receptor-ligand pathway of apoptosis?

Answer 52

Fas ligand binds to Fas death receptor (CD95)

Question 53

How are maturing T cells killed in the thymus if they do not pass positive or negative selection?

Answer 53

Fas-L and receptor

Question 54

What are the three major pathways of apoptosis activation?

Answer 54

1. Intrinsic mito pathway 2. Fas-Fas-L interaction 3. Cytotoxic CD8 T cell

Question 55

How do CD8+ T cells cause apoptosis? (2 enzymes)

Answer 55

Perforins create pores in membrane or target cell, and granzyme enters pore and activates caspases