Question

multiple choice question
release of factor xii by platelets initiates the ______ mechanism of coagulation.

○ extrinsic

○ intrinsic

Explanation:

In the coagulation process, the intrinsic pathway is initiated by factors present within the blood, like factor XII (Hageman factor) released by platelets or exposed to subendothelial collagen. The extrinsic pathway is initiated by tissue factor (factor III) from outside the blood. Since factor XII is a blood - borne factor, its release by platelets initiates the intrinsic mechanism.

Answer:

B. intrinsic