CLINICAL ENCOUNTERS
ANTICOAGULATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Extrinsic and intrinsic
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Primary and secondary
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Extinsic or intinsic
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None of the above
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Detailed explanation-1: -The intrinsic pathway consists of factors I, II, IX, X, XI, and XII. Respectively, each one is named, fibrinogen, prothrombin, Christmas factor, Stuart-Prower factor, plasma thromboplastin, and Hageman factor. The extrinsic pathway consists of factors I, II, VII, and X. Factor VII is called stable factor.
Detailed explanation-2: -The extrinsic pathway consists of the transmembrane receptor tissue factor (TF) and plasma factor VII/VIIa (FVII/FVIIa), and the intrinsic pathway consists of plasma FXI, FIX, and FVIII. Under physiological conditions, TF is constitutively expressed by adventitial cells surrounding blood vessels and initiates clotting.
Detailed explanation-3: -All the components necessary for the clotting process to proceed are found in the blood. As such, the proteins required for such clotting to take place are part of the intrinsic pathway of blood coagulation.
Detailed explanation-4: -The intrinsic pathway of blood coagulation is so named due to the presence of all the required reactants of this pathway in the circulation, with no external protein source required (unlike the extrinsic pathway that requires exposure to extravascular tissue factor for triggering).