The process of blood clotting, also known as coagulation, is a complex series of steps that the body undergoes in response to an injury in order to stop bleeding and begin the process of healing. Here are the steps involved in blood clotting:
Vasoconstriction: When an injury occurs, the blood vessels in the affected area constrict, or narrow, to decrease blood flow and reduce bleeding.
Platelet activation: Platelets, which are small, disk-shaped cells found in the blood, become activated and begin to stick to the walls of the damaged blood vessels.
Platelet aggregation: Activated platelets release chemicals that attract more platelets to the site of the injury. These platelets then stick together, or aggregate, to form a plug that helps to stop the bleeding.
Formation of the fibrin mesh: The activated platelets release chemicals that stimulate the production of a protein called fibrin. Fibrin forms a mesh-like structure that helps to hold the platelet plug in place and strengthen the blood clot.
Blood clotting: The combination of the platelet plug and the fibrin mesh forms a blood clot that seals off the damaged blood vessel and stops the bleeding. Clot retraction: Once the blood clot has formed, the platelets in the clot contract, or shrink, to help pull the edges of the damaged blood vessel together and further seal the wound.
Clot dissolution: After the injury has healed, the body begins to dissolve the blood clot. This is done through the action of enzymes called plasminogen activators, which break down the fibrin in the clot.