Which coagulation factor is known as prothrombin?

Prothrombin is known scientifically as Factor II in the coagulation cascade. It plays a critical role in hemostasis, which is the process that prevents and stops bleeding. Prothrombin is synthesized in the liver and is converted into thrombin during the coagulation process, specifically when the intrinsic and extrinsic pathways lead to the formation of a complex that activates Factor X. Thrombin, the active form of prothrombin, then plays a key role in converting fibrinogen (Factor I) into fibrin, leading to the formation of a stable blood clot. This makes Factor II essential for proper blood coagulation and the maintenance of hemostasis in the body.

The other factors mentioned, such as Factor I (fibrinogen), Factor III (tissue factor), and Factor VIII (antihemophilic factor), have different roles in the coagulation pathway and are not associated with the name prothrombin.