final review Flashcards
what does PFA test measre
closure time for platelet plug
interpret results and name the disorder and dysfunction:
- PT, APTT and PLT count normal
- increased bleeding time
- abnormal aggregation curves except ristocetin
- Glanzmann’s thrombathenia
- missing Gp2b-3a, altering platelet aggregation
how does TPO work
- TPO binds PLT receptors and is degraded
- if no platelets to bind TPO, will increase and stimulate megakaryocyte production
which disorder is characterized by prolonged bleeding time, giant platelets, and platelet aggregation studies normal with all agents except ristocetin
bernard soulier
in HIT, the antibody is only active in the presence of what substance?
heparin
what is the anitbody associated with HIT/HITTS
anti PF4-heparin complex (IgG)
what is the name of the vascular layer mae=de of broad flat endothelial cells
tunica intima
what receptor does vWF adhere to on the platelet?
What disorder is this receptor deficient in
- GP-1b
- bernard soulier
what is the role of Glycocalyx, the outer membrane of platelet
mediates adhesion and aggregation
name 6 components of platelet granules
- ADP
- Ca
- serotonin
- TXA2
- vWF
- fibrinogen (FI)
what is the role of TXA2
secreted for platelet activation and aggregation
name the role of ADP and TXA2
expose Gp2b-3a
recruit more platelets to injury site
how does prostacyclin contribute to vascular funciton in hemostasis
normally inhibits platelet adhesion
vasodilator
plasmin can lyse both fibrin and fibrinogen; fibrinogenolysis is usually harder to achieve, why?
antiplasmin will destroy most plasmin that escapes the clot
name at least so exogenous plasminogen activators
streptokinase
urokinse
tPA
