Cell Injury

Question 1

what are some examples of cell injury causes

Answer 1

hypoxia, physical agents (temp, radiation, trauma), immunological reactions, nutritional imbalances

Question 2

what type of mechanism can cause cell damage

Answer 2

ATP depletion, free radicals, loss of intracellular homeostasis, defects in membrane permeability

Question 3

what are the three types of cell injury

Answer 3

reversible eg loss of atp, membrane integrity, defects in protein syn
irreversible - persistent or excessive injury eg mitochondria swelling, lysosome swelling, leakages of membranes
ischaemic reperfusion injury - when o2 returns to tissue after period of ischaemia

Question 4

what is cell swelling caused by and what type of cel injury is it

Answer 4

reversible - caused by decreased atp

decreased Na/k pump, increased Na in the cell - more water by osmosis - swelling

Question 5

what is apoptosis

Answer 5

programme cell death (individual level)

death is by membrane blobbing to form apoptotic bodies

Question 6

what is necrosis

Answer 6

death of cell via pathological causes 
induces repair or regeneration 
affects large areas of cells 
cell swelling 
loss of control of intracellular environment

Question 7

what is the difference between necrosis and apoptosis

Answer 7

apoptosis - cells shrink, individual, no inflammatory response, cell contents taken up by neighbouring cells, apoptotic bodies, chromatin condensation and dna degradation

necrosis - swelling, many cells, ingested by macrophages, inflammatory response, loss of membrane integrity, cell lysis, organelle swelling, random degradation of DNA

Question 8

what induces cell death in both necrosis and apoptosis

Answer 8

apoptosis - caspases pathway activation = no inflammatory response

necrosis - cell swelling and loss of membrane integrity = inflammatory response

Question 9

what are the 6 types of necrosis

Answer 9

coagulative - most common (myocardium frequent) - become ghost cells
liquefactive/colliquative (in brian) - lack of stroma = cyst formation
gangrenous - infection
caseous - caused by internal death eg TB infection
fat necrosis - enzymes or trauma - fat enters cells and calcifies
fibrinoid necrosis - malignant hypertension and autoimmune conditions