Test Taking Tip
Hematology requires lots of memorization. Important topics to look over include bleeding disorders and the various anticoagulants. These are basic questions you don’t want to miss.
Sequence of the intrinsic pathway of coagulation:
Prekallikrein + HMW kininogen + factor XII + exposed collagen → activates factor XI → activates factor IX, combines with factor VIII → activates factor X, combines with factor V → converts prothrombin (factor II) into thrombin. Thrombin converts fibrinogen into fibrin.
Schematic of the coagulation system. HMW, high molecular weight. (Reproduced with permission from Brunicardi FC, Andersen DK, Billiar TR, et al: Schwartz’s Principles of Surgery, 9th ed. New York, NY: McGraw Hill; 2010.)
Sequence of the extrinsic pathway of coagulation:
Which factor is the convergence point and common to both the extrinsic and intrinsic pathways of coagulation?
What does the prothrombin complex consist of?
What function does thrombin have?
Which factor has the shortest half-life?
What factor can be used to differentiate a consumptive coagulopathy from hepatocellular disease?
Which factors are known as the labile factors (activity lost in stored blood)?
What function does factor XIII have?
What does Von Willebrand factor (vWF) do?
What is the function of antithrombin III?
Binds heparin, inhibits factors IX, X, XI, and thrombin
Where does tissue plasminogen activator come from, and what does it do?