How does the process of blood clotting occur?

The function of a blood clot is to prevent blood loss from damaged blood vessels. In order for a blood clot to form, activated platelets and the damaged tissue release clotting factors which are proteins in the blood that control bleeding. The clotting factors then catalyse the reaction of the inactive zymogen, prothrombin to the active form, known as thrombin. Thrombin catalyses the conversion of soluble fibrinogen into insoluble fibrin which forms a mesh of fibres over the damaged area to help trap blood cells. The platelets can then stick to the area of damage and form a solid clot. This mechanism is vital as it prevents serious blood loss and stops pathogens from entering the body via the injury.