Flashcards in Defects of Coagulation mechanism Deck (55)
What are the 3 main types of bleeding disorders?
acquired platelet defects
inherited bleeding disorders
What is hemostasis?
process that prevents blood loss form damaged blood vessels
What is thrombosis?
pathological formation of a 'hemostatic' plug within the vascularture in the absence of bleeding
What important factor is needed for platelet adhesion? Receptor?
What important factor is needed for platelet aggregation? Receptor?
What is contained in dense granules in the platelet?
What does calcium release lead to?
What are the 2 binding domains on vWF?
What does binding of vWF with GP1b cause?
braking/activation of the platelet
What does binding of vWF ith GPIIb/IIIa cause?
arrest of the platelet
What does platelet granule release lead to?
signals other platelets
What does platelet membrane coagulant expression lead do?
thrombin and clot
Initiation phase of cell based coagulation
activaion of IXa & Xa
Xa converts II to IIa (thrombin)
Amplification phase of cell based coagulation
thrombin activated Va, VIIIa, XIa and platelets
Propagation of cell based coagulation
IXa catalyzing further thrombin formation
XIa augments by driving further IXa formation
Thrombin driven pahse of cell based coagulation
transformation of fibrinogen to fibrin and cross linking
What are the vitamin K dependent pro coagulant factors?
II, VII, IX, X
What are the vitamin K dependent anti coagulant factors?
Proteins C & S
What does thrombin activate?
Fibrinogen to fibrin
What does an intrinsic pathway deficiency lead to?
What does an extrinsic pathway deficiency lead to?
What enzymes are important for the fibrinolytic system?
What does active protein C do?
proteolysis of factors Va and VIIa
What does mucosal bleeding usually indicate?
platelet defect of vWF
What does deep tissue bleeding usually indicate?
Generalized oozing at venipuncture sites is indicative of?
What are screening tests done for platelet phase problems?
What are screening tests done for coagulation phase problems?
Inhibitor screening (1:1 mix)
How do we check for quantitative defects of platelets?
peripheral blood film
Vit B12, PF4 ELISA