Cellular Injury

Question 1

Type of cellular adaptation that ⬇️ in tissue mass due to ⬇️ in size and/or number of cells

Answer 1

Atrophy

Question 2

Pathway that cell uses to ⬇️ size of tissue in atrophy

Answer 2

⬆️ cytoskeleton degradation via ubiquitin-protease pathway and autophagy.
Also ⬇️ protein synthesis

Question 3

Earliest morphologic manifestation of reversible cell injury. Due to ⬇️ activity of Ca2+ and Na/K pumps

Answer 3

Cellular and mitochondrial swelling

Question 4

Nuclear manifestations in irreversible cell injury

Answer 4

Pyknosis, karyorrhexis and karyolysis

Question 5

DNA change indicative of cell apoptosis

Answer 5

Fragments in multiples of 180bp (DNA laddering)

Question 6

Family of proteins that regulates apoptotic intrinsic (mitochondrial) pathway

Answer 6

Bcl-2 family.

BAX and BAK are proapoptotic, Bcl-2 and Bcl-xL are antiapoptotic

Question 7

This apoptotic pathway needs Fas-FasL interaction, TNFα or cytotoxic T-cell release of perforin & granzyme B

Answer 7

Death receptor pathway (extrinsic)

Question 8

Local inflammatory reaction due exogenous injury that leads to plasma membrane damage

Answer 8

Necrosis

Question 9

Type of necrosis seen in ischemia/infarct, the injury denatures enzymes, preserved cellular architecture, eosinophilia

Answer 9

Coagulative necrosis

Question 10

Type of necrosis seen in bacterial abscesses and brain infarcts, where neutrophils release lysosomal enzymes. Early → cellular debris and macrophages
Late → cystic spaces and cavitation

Answer 10

Liquefactive necrosis

Question 11

Fragmented cells and debris surrounded by lymphocytes and macrophages

Answer 11

Granuloma

Question 12

Mention the 2 subtypes of fat necrosis

Answer 12

• Enzymatic: acute pancreatitis

- Nonenzymatic: traumatic, like injury of breast tissue

Question 13

This type of necrosis is due to immune complex deposition and/or plasma protein leakage from damaged vessel. Seen in PAN or preeclampsia

Answer 13

Fibrinoid necrosis

Question 14

Gangrenous necrosis can be due two situations, which ones?

Answer 14

Dry gangrenous necrosis: ischemia

Wet gangrenous necrosis: superinfection

Question 15

Neurons that are most vulnerable to hypoxic-ischemic insults

Answer 15

Purkinje cells of the cerebellum and pyramidal cells of the hyppocampus and neocortex

Question 16

Type of infarct that occurs in venous occlusion and tissues with multiple blood supplies, as well as with reperfusion

Answer 16

Red infarct

Question 17

Yellow-brown “wear and tear” pigment associated with normal aging, composed of polymers of lipids and phospholipids complexed with protein

Answer 17

Lipofuscin

Question 18

Abnormal aggregation of proteins into beta-pleated linear sheets that make insoluble fibrils, leading to cellular damage and apoptosis

Answer 18

Amyloidosis

Question 19

Amyloid deposits can be in which type of stains

Answer 19

Congo red stain: red/orange on nonpolarized light; apple-green birefringence on polarized light)
H&E stain