Question

multiple choice question
what initiates the extrinsic mechanism of coagulation?
prostacyclin coating the endothelium
clotting factors in the plasma
factors released by damaged blood vessels or tissues
myeloblasts released prematurely from the bone marrow

Explanation:

The extrinsic mechanism of coagulation is initiated by tissue - factor (also known as tissue thromboplastin) which is released by damaged blood vessels or tissues. Prostaglandin coating the endothelium inhibits platelet aggregation. Clotting factors in the plasma are involved in the cascade but not the initiator of the extrinsic pathway. Myeloblasts released prematurely from the bone marrow are not related to initiating the extrinsic coagulation mechanism.

Answer:

Factors released by damaged blood vessels or tissues