Koagulationsbahn

The Koagulationsbahn, also known as the coagulation cascade, is a series of biochemical reactions in the blood that lead to the formation of a clot. This process is crucial for preventing excessive bleeding and maintaining hemostasis, the body's ability to stop bleeding. The cascade is initiated by the exposure of subendothelial tissue, which triggers the release of tissue factor (TF) from damaged cells. TF then binds to factor VII (FVII) and factor X (FX), forming a complex that activates FX to FXa. FXa, in turn, activates factor II (FII), also known as prothrombin, to FIIa, which is thrombin. Thrombin plays a central role in the cascade, as it converts fibrinogen to fibrin, which forms the mesh-like structure of the clot. Additionally, thrombin activates factor XIII (FXIII), which stabilizes the fibrin clot by cross-linking fibrin molecules. The Koagulationsbahn is tightly regulated by natural anticoagulants, such as antithrombin and protein C, to prevent excessive clotting and the formation of unwanted blood clots. Dysregulation of the coagulation cascade can lead to conditions such as thrombosis and hemorrhage.