Blood Clots Flashcards
3 steps of clot formation
vessel constriction, platelet adhesion, cross linking of fibrin through coagulation cascade
Prostaglandin F 2a and Thromboxane A2 are what?
Potent vasoconstrictors-helps limit hemorrhage
ADP and Serotonin are involved in what?
platelet aggregation
coagulation cascade is intitiated by what?
TF binding with factor VII which activates it to VIIa
Is intrinsic or extrinsic pathway more important?
extrinsic
cascade ultimately leads to
Thrombin which activates Factor XIII that cross links the fibrin mesh
small protein that is a serine protease inhibitor-inactivates coagulation
Antithrombin
Protein C zymogen is activated when it
binds to thrombin
single chain polypeptide which can reversibly inhibit factor Xa
Tissue factor pathway inhibitor
which protein cuts fibrin to help break down clots?
plasmin
Streptokinase, urokinase, reteplase, alteplase, tenecteplase are all
fibrinolytics-used to break down thrombi
these drugs act on antithrombin
indirect thrombin inhibitors-heparin
Fondaparinux works exactly like____
Heparin-binds to AT
Drugs that act on anti-thrombin are considered what?
indirect inhibitors
Drugs that act on fibrinogen and block its activity are considered
direct thrombin inhibitors
Coumarins (anti coagulant) works by what mechanism?
Blocks the conversion of oxidized vitamin K back to the reduced form. The body then runs out of reduced vitamin K and thrombin becomes inactive.
antidote for warfarin overdose
vitamin K, aqua mephyton
Antidote for heparin overdose
protamine sulfate
Aspirin inhibits what?
thromboxane A2 synthesis
Clopidogrel works by blocking what?
ADP receptors
Epifbatide and tirofiban work by blocking what?
GPIIb/IIIa
Bleeding disorders are treated by what?
replacement therapy
