1. Platelets help in clotting of blood at the site of injury thus it controls the loss of blood from the wound.
2. When blood flows out, the platelets release an enzyme called THROMBOK1NASE.
3. This acts on another substance called PROTHROMBIN converting it into THROMBIN.
4. Thrombin acts on FIBRINOGEN, converting it into FIBRIN.
5. The blood cells entangle in the fibrin fibres forming the CLOT.
6. Prothrombin \(\overset{Thrombokinase}{\longrightarrow}\) Thrombin
FIbrinogen \(\overset{Thrombin}{\longrightarrow}\) Fibrin → clot.