Clotting Cascade Flashcards
What are the steps from tissue injury to the common pathway for the extrinsic pathway?
Tissue Injury
Factor III (Tissue Factor) released
Tisue factor turns Factor VII into Factor VIIa
Factor VIIa turns Factor X into Factor Xa
Which factors are vitamin K dependent?
Factors II, VII, IX, X
What all makes up prothrombinase?
Factor Va
Factor Xa
Ca2+
What is the role of thrombin in the polymerization of fibrin?
It activates Factor XIII, which crosslinks fibrin polymers to form “stable fibrin.”
Thrombin catalyzes the activation of which two factors?
Factor V and Factor VIII
What lab test primarily tests the extrinsic and common pathway?
What factors of the extrinsic pathway are tested?
Prothrombin time
Just VII
What lab test primarily tests the intrinsic and common pathway?
Activated partial thromboplastin time
(Remember that kaolin is used for the negative surface in activated partial thromboplastin time tests.)
What test measures the activity of Heparin?
Activated partial thromboplastin time
Which factors are inhibited by heparin?
II, IX, and Xa
Which factors are inhibited by coumadin?
The ones that use Vitamin K
II, VII, IX, X
