Extrinsic pathway of coagulation is tested by?

Simple tricks to remember questions of hemostasis: Intrinsic pathway – XII —>  XI —>  IX —>  X (Help of VIII, IV) Extrinsic pathway – III —> VII —> X Common pathway – X —> II —> I —>  fibrin plug (help of V, XIII) Vitamin K dependent clotting factors - 2, 7, 9, 10 (protein C and S) - mainly extrinsic pathway Vitamin K antagonists - Coumarin derivatives (dicoumarol) and warfarin