ABSTRACT
Overview of Coagulation System The coagulation system has 2 essential functions: to maintain hemostasis and to prevent and limit thrombosis. The procoagulant component of the hemostatic system prevents and controls hemorrhage. Vascular injury results in activation of hemostasis, which consists of vasospasm, platelet plug formation (platelet activation, adhesion, and aggregation), and fibrin clot formation (by activation of coagulation factors in the procoagulant system). The anticoagulant system prevents excessive formation of blood clots, and the fibrinolytic system breaks down and remodels blood clots. Quantitative abnormalities (deficiencies) and qualitative abnormalities of platelets and coagulation factors lead to bleeding disorders, whereas deficiencies of the anticoagulant system are risk factors for thrombosis.
