Cell injury & death

Question 1

List 3 common causes of reversible cell injury

Answer 1

trauma (concussion, frost bite)
hypoxia
ischemia

Question 2

What can cause hypoxia?

Answer 2

(Don’t confuse with ischemia)
decreased availability of O2
loss of oxygen carrying capacity of blood (RBC)

Question 3

Differentiate ischemia from hypoxia.

Answer 3

Ischemia - absence of oxygen and nutrients

Hypoxia - absence of oxygen

Question 4

List the two ways cells can die.

Answer 4

apoptosis

necrosis

Question 5

(T/F) All cells can undergo apoptosis.

Answer 5

True

Question 6

Is inflammation seen during apoptosis?

Answer 6

No

Question 7

Where is apoptosis commonly seen physiologically?

Answer 7

Physiologic

• embryogenesis constituent feature
• hormone induced changes
• mild trauma or injury removing nonfunctioning cells

Question 8

Where is apoptosis seen pathologically?

Answer 8

Pathologically

• some tumors
• chemotherapy & radiotherapy
• immune reactions usually by cellular mechanisms
• atrophy terminal event
• graft vs. host disease
• some viral diseases

Question 9

Apoptosis is induced by what 4 events?

Answer 9

1. calcium sensitive endonuclease leading to pyknosis
2. transglutaminase activity causes cytoplasmic atrophy
3. phagocytes bleb
4. gene activation via protein syntehesis of bcl-2, c-myc and p53 promoting apoptosis

Question 10

What happens to the cell after pyknosis?

Answer 10

karyorrhexis

Question 11

Death by apoptotic mechanisms.

Answer 11

aging

Question 12

What are the 4 major forms of necrosis?

Answer 12

coagulative necrosis
liguification necrosis
fat necrosis
caseous necrosis

Question 13

What does the type of necrosis depend on?

Answer 13

type of tissue and agent

Question 14

Coagulative necrosis is seen in hypoxic death in all tissues except?

Answer 14

brain

Question 15

Two common settings for liquefactive necrosis

Answer 15

brain infarct and tissue/brain abscess

Question 16

What is one of the leading causes of infantile death?

Answer 16

brain trauma

Question 17

Define fat necrosis.

Answer 17

Saponification of fat cells with calcification due to enzymatic breakdown of lipases. Form of dystrophic calcification. “soap deposits”

Question 18

What is the most common cause of fat necrosis? second?

Answer 18

trauma

alcoholism

Question 19

What kind of trauma causes fat necrosis?

Answer 19

Trauma to a fatty organ

Question 20

Why does resulting trauma in fat necrosis feel hard?

Answer 20

fatty soap; common in breasts

Question 21

Name types of biopsies?

Answer 21

needle biopsy, core biopsy, incisional biopsy (wedge), excisional biopsy

Question 22

Describe caseous necrosis.

Answer 22

amorphous debris and surrounding granuloma

Question 23

What is caseous necrosis a reaction to?

Answer 23

bacteria

Question 24

What is gangrenous necrosis?

Answer 24

Not a distinct type but a combo pattern; applied to hypoxic limbs, combo of coagulative and liquefactive necrosis

Question 25

Coagulative necrosis due to

Answer 25

ischemia causes cell death and bacteria capitalizing on

Question 26

Fibrinoid necrosis

Answer 26

accumulation of eosinophilic amorphous proteinaceous material in tissue matrix
staining pattern reminiscent of fibrin

Question 27

What are the risks of angioplasty?

Answer 27

procedural, hemorrhagic, and reperfusion injury; arthrosclerosis can be dislodged

Question 28

Would you use angioplasty for a middle cerebral artery?

Answer 28

Not if there is liquifactin necrosis in the brain; can cause hemorrhage

Question 29

What type of necrosis might be found in the feet of a diabetic?

Answer 29

Gangrenous necrosis

Question 30

What represents irreversible cellular damage?

Answer 30

nuclear pyknosis

Question 31

What is the most commonly occluded artery in the brain?

Answer 31

middle cerebral artery

Question 32

What is a likely pathologic event from an occluded MCA?

Answer 32

cerebral softening from liquefactive necrosis

Question 33

Blood culture with Strep. viridans. 1 cm vegetation on mitral valve. Pathologic changes?

Answer 33

Necrosis