CELL INJURY HIGH YIELD

Question 1

what are the two types of cell injury?

Answer 1

reversible cell injury

irreversible cell injury

Question 2

causes of cellular injury?

Answer 2

oxygen deprivation
physical agents
chemical agents
infectious agents
immunologic reactions
genetic derangements
nutritional imbalances

Question 3

cellular responses to injurious stimuli depends on?

Answer 3

type of injury
duration
severity

Question 4

consequences of cell injury depends on?

vulnerable systems?

Answer 4

type of cell
state of cell
adaptability

cell membrane integrity
aerobic respiration
protein synthesis
integrity of genetic apparatus (RNA/DNA)

Question 5

what are the general mechanisms of cell injury?

Answer 5

ATP depletion
accumulation of oxygen deprived free radicals
loss of calcium homeostasis
defects in membrane permeability
damage to DNA and proteins
mitochondrial damage and dysfunction

Question 6

ATP depletion is based on?

Answer 6

failed Na+ pumps
increased glycolysis
failure of Ca2+ pumps
depletion of ATP

Question 7

ROS is generated by what 2 major pathways?

Answer 7

reduction oxidation reactions
produced in phagocytic leukocytes
nitric oxide

Question 8

what are the harmful effects due to the loss of calcium homeostasis?

Answer 8

decreases ATP via atpase
decreased phospholipids b/c of phospholipase
disrupts cell membrane and cytoskeleton proteins (proteases)
damage nuclear chromatin (endonucleases)

Question 9

persistent of severe injury can cause irreversible injury such as?

Answer 9

inability to reverse mitochondrial dysfunction

disturbance in membrane function

Question 10

what is the effect of ischemic/reperfusion injury?

*what are the new damaging processes?

Answer 10

sustains loss of cells in addition to the cells that are irreversibly damaged at the end of ischemia

i. e- myocardial infarction, stroke, organ transplantation
* generation of oxygen free radicals during reperfusion

production of cytokines and increased expression of adhesion molecules

Question 11

chemicals induce cell injury by two general mechanisms?

Answer 11

direct acting

convert to toxic metabolites

Question 12

these initiate autocatalytic reactions?

Answer 12

free radicals

Question 13

free radicals seem to be a final common pathway for cell injury in these varied processes?

Answer 13

chemical damage
radiation damage
cellular aging
inflammation

Question 14

formation of the free radials is due to?

Answer 14

radiation
endogenous redox reactions
metabolism of exogenous chemicals or drugs
transition metals
nitric acid

Question 15

effects of free radicals?

Answer 15

lipid per oxidation of membranes
oxidative modification of proteins
DNA fragmentation

Question 16

protective mechanisms of free radicals?

Answer 16

antioxidants
spontaneous decay
binding transition metals to proteins
free radical scavenging enzymes

Question 17

what are the sub cellular responses to injury?

Answer 17

lysosomal catabolism
heterophagy
autophagy
induction of SER
mitochondrial alterations
cytoskeletal abnormalities 
heat shock proteins

Question 18

heat shock proteins play important roles in?

Answer 18

• protein folding
• disaggregation of protein-protein complexes
• transport of proteins into intracellular organelles
• reforming of denatured polypeptides
• tagging irretrievable denatured proteins