final lecture 3 Flashcards
important functions of hemostasis
upon damage- arrests bleeding
normally-maintains blood flow
thrombosis
forms a blot in an intact blood vessel
hemostasis & thrombosis involve 4 major components
vascular endothelium, plts, coagulation system, fibrinolytic system
each rxn results from the interactions of:
an enzyme, substrate, and cofactor
vitamin K dependent factors
II, VII, IX, X
contact activated factors/ beginning of intrinsic cascade
XII, prekallikrein, high molecular weight kininogen
thrombin sensitive factors
I-fibrinogen, V, VIII, XI, XIII
hemostasis events in response to vascular injury
localized vascular spasms, primary hemostasis, secondary hemostasis, clot dissolution
primary hemostasis
formation of primary plt plug & involves plts, blood vessel wall & von willeebrand factor
plt adhesion is mediated by ____ in primary hemostasis
von willebrand factor
Plt-plt binding is mediated by___
fibrinogen which binds to GPIIb/IIIa on adj plts
secondary hemostasis
formation of fibrin through the coagulation cascade
initiation of coagulation
extrinsic pathway aka rapid response
thrombin-sensitive factors
V, VIII, XI
secondary hemostasis actions
plt activation & aggregation, fibrinogen->fibrin, activates XIII