haemostasis and blood clotting Flashcards
name the 4 stages of haemostasis
vascular injury
platelet activation
platelet plug formation
coagulation cascade
what occurs in vascular injury (2)
collagen exposed
nervous system causes vasoconstriction
what occurs during platelet activation
vWF binds to damaged collagen and platlets bind to vWF, activating them
what is released by platelets in plug formation (4)
serotonin
thromboxane
Ca2+
ADP
what occurs in platelet plug formation
platlets bind to bibringen and aggregate
what occurs in coagulation cascade
fibrinogen is converted to fibrin mesh by thrombin
what molecule breaks down fibrin mesh once blood vessel is repaired
plasmin
what factors in coagulation cascade are dependant on vitamin K
10
9
7
2
what does warfarin do
reduces vitamin K, reducing blood clotting
what factor of clotting cascade is deficient in a patient with Haemophilia A
7
what factor of clotting cascade is deficient in a patient with Haemophilia b
9
what factor of clotting cascade is deficient in a patient with Haemophilia C
11
what does aspirin do
antiplatlet drug- stops platelet adhering to endothelium
what does heparin
blocs factor Xa in clotting cascade
