How does blood clot and a wound heal?
Whenever an injury takes place in which bleeding occur, clotting and blood coagulation are initated to stop the bleeding.
Clot formation starts when platelets come in contact with a damaged blood vessel. They tend to stick to the irregular surface of the blood vessel and build up to plug it, if it is narrow enough. This also initiates the production of thrombia, an enzyme which catalyzes the conversion of the plasma protein fibrinogen into string like molecules called fibrin. Fibrin molecules adhere to one another forming a fibrons matrix which immobilizes the fluid portion of the blood, causing it to solidify. It also traps the RBCs and platelets to further increase the density of the clot. Within half an hour, the platelets contract, pulling the flesh tighten and forcing the liquid out. This action creates a denser and stronger clot on the skin called a scab and it also constricts the wound pulling the damaged surfaces closer together to promote healing.
