Cell Injury Lec 2

Question 1

What are the agents and stimuli that can lead to cell injury?

Answer 1

1. Hypoxia (low 02) and anoxia (no o2)
2. Toxins
3. Chemicals(cyanide, sodium chloride)
4. Physical agents
5. immune responses (nitrogen, hydrogen peroxide, kills tissues)
6. infectious agents-bacteria , viruses

Question 2

What are cellular elements that are vulnerable to cell injury effects:

Answer 2

1. plasma membrane
2. mitochondria
   3.ionic channels in the cell mem
3. cytoskeleton
   5.DNA

Question 3

What are biochemical events that mediate cell injury:

Answer 3

1. Low oxygen derived free radicals(o2-, H2o2, OH-)
2. lead to increase in Ca+2 inside the cell
3. increase in Ca+2 activates many enzymes: phospholipases(membrane-phospholipids)
   -proteases(ctyoskeleton)
   -endonucleases(DNA)
4. ATPase activity increases(depletion of ATP)

Question 4

What inactivates free radicals?

Answer 4

Vitamin: A,C,E
cysteine, glutathione, ceruloplasmin, and transferrin
Superoxide dismutase, catalse, glutathione peroxidase

Question 5

What are reversible conditions?

Answer 5

Swelling of : cell, mitochondria, ER
-detachment of ribosomes from the ER
-loss of microvilli
surface blebs
clump of nuclear chromatin
lipid deposition

Question 6

What are irreversible conditions:

Answer 6

1. release of lysosomal enzymes
2. protein digestion-plasma membrane and mitochondria membrane and disruption
3. nuclear shrinkage, disintegration, and dissolution
   Ca plays a central role in progression to irreversible cell death

Question 7

What is pyknosis?

Answer 7

shrinkage-condense

Question 8

What is karyorrhexis:

Answer 8

parts of breakage outside cell

Question 9

What is karyolysis?

Answer 9

small you cannot see, disappear

Question 10

What is cell death?

Answer 10

necrosis: the morphological changes in tissues caused by cell death due to cell injury
dead cell not really necrotic

Question 11

What are different patterns of necrosis:

Answer 11

1. coagulative
   2.liquefactive
   3.caseous
2. fat necrosis
3. gangrenous

Question 12

coagulative necrosis?

Answer 12

intitial preservation of cellular outline and tissue architecture (loss of nuclie)
heart infraction, kidney infraction

Question 13

Liqefactive necrosis:

Answer 13

transformation of solid tissue into fluid
powerful hydrlytic enzymes that disintegrate the cellular components and produce soup filled cyst

Question 14

caseuous necrosis?

Answer 14

tissue resembles soft crumbly cheese
this is typical in TB and some fungal infections

Question 15

fat necrosis?

Answer 15

breast tissues, pancreas
lipasses
chalk white

Question 16

Gangrenous necrosis:

Answer 16

start with hypoxia injury;
A. Dry gangrene (Coagulative)
B. Wet gangrene(liquefactive)
C. Gas gangrene (clostridium)