The endpoint of activity for both the extrinsic and intrinsic pathways for coagulation is the activation of factor X. Reactions beyond this point are common to both pathways, and involves the combining of activated factor X with procoagulants (factor II, factor V, calcium ions, and platelet phospholipids) to form a prothrombinase complex. This complex catalyzes the conversion of circulating prothrombin into thrombin, which in turn converts circulating fibrinogen into insoluble fibrin. The coagulation process is terminated by the stabilization of fibrin via the activation of factor XIII.
Speiss BD. Perioperative coagulation concerns: Function, monitoring, and therapy. Clinical Anesthesia Updates. 1993;4:1-14