Mod4: platelet plug

Question 1

Where on the plt are receptors and Thromboxane A2 formed

Answer 1

peripheral zone

Question 2

TXA2 responsible for

produced by

Answer 2

plt aggregation

produced by COX1 arm of arachidonic pathway (blocked by aspirin)

Question 3

Main receptor responsible for plt aggregation
binds w (5)

Answer 3

GP2b/3a
von wellebrand
fibrinogen, fibronectin, vitronectin
thrombospondin

Question 4

How does clopidogrel work

Answer 4

~friend of cAMP (prevents adhesion)~
ADP stimulates P2Y12 and inhibits cAMP
clopidogrel blocks P2Y12 receptor
cAMP not inhibited, can block plts from touching

Question 5

Sol gel zone

inner most layer

Answer 5

structural support

contains organelles

Question 6

Activation
injury exposes (4)

Answer 6

injury exposes vWF, fibronectin, collagen, thrombospondin
collagen activates plts
plts aware of injury, change shape

Question 7

Adhesion
vWF binds to exposed ____ and to _____
collagen binds to ____ activating _____ and ______

Answer 7

circulating vWF binds to exposed collagen and to GPIb/9/5 receptors on plts
collagen binds to GP6 =activates GP2a/3b (binds w vWF) and GP1a/2a receptors (collagen)
extra binding anchors plts in place

Question 8

aggregation

Answer 8

fibrinogen binds to GP2b/3a receptors binding plts together

Question 9

Secretion

Answer 9

plt granules release contents
Fibronectin and thrombospondin: stablize plts
ADP: (^adhesion, activates/recruits plts)
Serotonin:recruits plts
Thromboxane A2: ^vasoconstriction/aggregation
Growth factors:tissue repair ~ atherosclerosis

Question 10

End products of coagulation cascade

Answer 10

fibrin and XIIIa -stabilize plt plug