The blood coagulation cascade.

The coagulation cascade is divided into an intrinsic and an extrinsic pathway. Coagulation factors are represented in blue and are designated by an “a” upon activation. Arrows symbolize the proteolytic conversion. Cofactors are marked in red and coagulation inhibitors in green. Proteins that participate in fibrinolysis have a brown color. The following abbreviations are used: F, factor; HK, high molecular weight kininogen; PAI-1, plasminogen activator inhibitor; PK, plasma kallikrein; TAFI, thrombin activatable fibrinolysis inhibitor; TFPI, tissue factor pathway inhibitor; tPA, tissue plasminogen activator; and uPA, urokinase-type plasminogen activator. Strong and weak interactions are indicated by solid and dotted lines.