Cell Injury and Cell Death 02

Question 1

list 3 occasions where cells are injured

Answer 1

• when they are stressed and cannot adapt
• when they are exposed to damaging agents
• they suffer intrinsic abnormalities

Question 2

is cell injury reversible?

Answer 2

it can be, but it can also be irrevesible (apoptosis, necrosis)

Question 3

what are the causes of cell injury

Answer 3

• anoxia
• physical/ chemical/ infectious agents
• immunoloical reactions
• genetic defects
• nutritional imbalances

Question 4

what is hypoxia

Answer 4

the deficiency of oxygen. it reduced aerobic oxidative respiration

Question 5

list a few causes of hypoxia

Answer 5

• ischemia
• not enough oxygen in blood due to cardiorespiratory failure
• decreased oxygen carrying capacity of blood ( CO poisioning / anemia)

Question 6

list physical harmful agents

Answer 6

mechanical trauma, extreme temperatures, changes in atm pressure, radiation, electric shock

Question 7

a cells response to injury depends on?

Answer 7

type of injury, duration, and severity

Question 8

consequences of injury depend on

Answer 8

type of cell, state of cell, adaptability of the injured cell

Question 9

list 4 reversible changes after injury

Answer 9

cellular swelling, cell membrane blebs, detached ribosomes, chromatin clumping

Question 10

list irreversible changes after injury

Answer 10

• lysosome rupture
• cell membrane rupture
• karyolysis
• karyorrhexis
• pyknosis

Question 11

what is a hydropic change?

Answer 11

it is an early response to cell injury. it is the accumulation of water in the cell.

Question 12

give the order of cells responsiveness to ischemic necrosis

Answer 12

low: fibroblasts, epidermis, skeletal muscle
medium: myocardium, hepatocytes, renal epithelium
high: neurons

Question 13

what is cyclosporine

Answer 13

immunosuppressive drug used to prevent graft rejection) targets the
protein cyclophilin D

Question 14

increases Ca influx causes?

Answer 14

• phospholipases activity which damages cell membrane
• proteases activity which damages cell membrane and cytoskeleton
• endonuclease activity causing DNA damage

Question 15

why can reperfusion of an organ cause more damage?

Answer 15

because of incompletely metabolised prodeucts producing ROS on the re-introduction of oxygen.

Question 16

what is necrosis and how does it happen?

Answer 16

accidental death. Lysosomal enzymes enter the cytoplasm, and digest the cell.

Question 17

what are the patterns of necrosis

Answer 17

coagulative, liquefactive, caseous, fat, gangrenous, fibrinoid