stroke kahn academy medicine

Question 1

blood brain barrier

Answer 1

made up of endothilial cells
underlay - basal lamina
tight junctions - connector proteins to restrict unwanted molecules getting in
astrocyte endfeet - nourishment to endothelial cells

Question 2

4-6 hrs after an ischemic stroke

Answer 2

BBB starts to break down leading to inflammation leading to vasogenic oedema

Question 3

ischemic cascade

Answer 3

no 02
neurons lose ability to get energy in the form of ATP via aerobic metabolism
- switches to anaerobic metabolism
- 15x less energy than aerobic
- bi product lactic acid - in high enough quantities disrupts the normal acid base balance in the brain and damage neurons
- sodium/potassium pumps stop working
- sodium starts to build up in neuron
H2O notices high sodium concentration and dives into neuron to balance out high sodium concentration - cytotoxic oedema

sodium calcium pump stops working
- calcium increases inside the cell
high calcium causes neurotransmitters like glutamate to be released from the end of the cell - excites other neurons - flow on effect - following neurons release glutamate
too much calcium activates degridative enzymes such as proteases- which break down proteins inside the neuron
The calcium activates lipises which break down the cell membrane
- ions and harmful chemicals enter neuron
mitochondria break down and release apoptotic factors - causing apoptosis cascade and kill off cells

Question 4

what is tPA

tissue plasminogen activator

Answer 4

thrombolytic
activates a compound called plasminogen- naturally found in the body to break up clots
- tPA turns plasminogen to plasmin and breaks clots

Question 5

haemorrhagic stroke medication

Answer 5

antihypertensives to stop blood pressure getting too high
cessation of anticoagulants
elevated bed to lower ICP
?anticonvulsive