Platelets rupture, releasing thromboplatin Ca++ Prothrombin converted to thrombin fibrinogin converted to fibrin fibrin thread network, clot.
Prothrombin is a precursor protein that is converted into thrombin, an enzyme that plays a crucial role in the blood clotting process. Fibrinogen is a protein that is also involved in blood clot formation, as it is converted into fibrin, which forms a mesh-like structure to stabilize the clot.