6.2 Flashcards
define Hemostasis
arest of bleeding after an injury
pro and anti-coagulants
avoiding of thrombosis/bleeding disorders
3 mechanism of hemostasis
- vasoconstriction
- platelets aggregation
- blood coagulation
primary hemostasis refers to
immediate vasoconstriction
platelets activation
blood coagulation
secondary hemostasis refers to
formation of fibrin mash network
fibrinolysis
how does the immediate vasoconstriction occurs after vessel injury?
Endothelin release
neurogenic reflex
locally released vascoconstrictors (TXA2, serotonine, E, K+ ions)
3 steps of platelets
- adhesion
- activation
- aggregation
activated platelets release ____, ____
ADP
TXA2
in normal state, how do platelets activation being prevented?
actions of NO and Prostacyclins
major functions of platelets?
- addhesion and aggregation
- forming phospholipid surface for blood coagulation
- secrete granules with active molecules
shape and structure of platelets?
spherically shaped have glycoproteins and glycoproteins receptors contain dense granules a granules (with clotting factors) actin/myosin
how do platelets adhare to sub-endothelium space?
GP-VI
GP-Ia-IIa
job of vWf
stronger connection btw collagen and platelets via GP Ib-IX-V and vWf
what is the job of TXA2?
increases platelets activation
write down platelets activating factors
collagen TXA2 5-HT E Thrombin PAF
