Cell Injury 8-4-15

Question 1

Hyperplasia

Answer 1

number

Question 2

Hypertrophy

Answer 2

increase size

Question 3

Metaplasia

Answer 3

Type switch

-stem

Question 4

Hypoxia leads to…

Answer 4

1. decrease oxidative phosphorylation
2. decrease in ATP

a. decrease Na pump—>increase in Na and water in cell–> swelling
b. increase in anerobic glycolysis –>glycogen, increase lactic acid, Decreased PH—>clumping of nuclear chromatin
c. Detachment of ribosomes–>decrease protein synthesis–>lipid deposition

Question 5

How does loss of energy from hypoxia affect calcium?

Answer 5

increase calcium

-altered membrane permeability and activation of intracellular membranes

Question 6

What does reversible cell injury look like histologically and morphologically ?

Answer 6

histologically:
more pink-eosinophilia

morphology:

• cellular swelling
• steatosis
• myelin figures
• ER swelling
• membrane blebs

Question 7

What does irreversible cell injury look like?

Answer 7

fragmentation and loss of nuclei

Question 8

What is necrosis characterized by?

Answer 8

leukocytes (neutrophils)
-break down of plasma membrane organelles and nucleus; leakage of contents –>inflammatory

-pathologic

Question 9

Coagulation Necrosis
Histology
Macroscopically
Example

Answer 9

severe ischemia of solid organs
Histologically:
-eosinophilia
-ghost-like remnants of intact cells-lack nuclei

Macroscopically:
-tissue firm

Examples:

• Myocardial Infarct
• Renal Infarct

Question 10

Liquefactive Necrosis 
Histology
Microscopic
Macroscopically
Example

Answer 10

bacterial infection
Microscopic
-bacteria release enzymes causing a rapid loss of cellular structure and a collection of liquid
Macroscopic: creamy yellow material
-abscess=collection of neutrophils, dead cells, liquid

***Brain hypoxia

Question 11

Caseous Necrosis
Histologically
Macroscopically

Answer 11

CHEESE
granuloma
Histologically: Amorphous, granular debris (dead cells) in the center of granulomatous cell reaction
Macroscopically: Necrotic tissue is soft, white, friable

Question 12

Enzymatic Fat Necrosis

Answer 12

focal cell death in the pancreas and adjacent fat

Example: acute pancreatitis

Question 13

How does Pancreatitis lead to Enzymatic Fat Necrosis?

Answer 13

lipase–>peripancreatic adipose tissue–>free fatty acids+ calcium

Question 14

Gangrene

Answer 14

Coagulation necrosis of extremity, bowel, gallblader

Question 15

Wet Gangrene

Answer 15

bacteria contaminate dying tissue, superimposing liquefactive necrosis

Question 16

Apoptosis

Answer 16

regulated pattern of cell death

• nuclear condensation and fragmentation
• fragmentation of cytoplasm into apoptotic bodies
• pathologic and physiological
• no inflammation
• removal of dead cell by phagocytes

Question 17

What are the principle mechanisms of cell injury?

Answer 17

1. Mitochondria–> decrease ATP & increase ROS
2. Increase Cellular Calcium–>increase mito permeability & activation of enzymes
3. Integrity of Membranes
4. Integrity of Genetic Material, Protein misfolding

Question 18

What happens when ATP is decreased?

Answer 18

decreased intracellular oxygen

• aerobic–>anaerobic
• increased lactic acid–>metabolic acidosis

Question 19

What does ROS lead to? What are some examples?

Answer 19

Lipid peroxidation
Protein modification
DNA damage

Example:
Carbon Tetrachloride–>causes lipid peroxidation, damage to cell structure-dry cleaning

Reperfusion Injury:
-return of blood flow to ischemic tissue–>oxygen derived free radicals–> further injury to cells