Osmosis video - Coagulation (secondary hemostasis)

Coagulation is the process of formation of a blood clot. It is secondary hemostasis that occurs after vascular damage has occurred and platelets have been activated. Its purpose is to form the fibrin mesh necessary to stabilize the platelet plug to stop bleeding. Coagulation happens in a series of steps called the coagulation cascade, which is a series of enzymatic reactions that leads to the conversion of fibrinogen to fibrin. The final product is a stable plug that stops the bleeding. Factors XII, XI, IX, VIII, VII, V, and IV are essential for the initiation of coagulation. Proteins C and S inhibit the coagulation cascade by inactivating factors Va and VIIIa, respectively.