The process which controls the flow of blood following Vascular injury and the subsequent dissolution of the clot, after repair to the injured tissue, is haemostasis. Haemostasis is a normal physiological response, involving the dual pathways of platelet activation and coagulation cascade initiation, thus preventing blood loss. It serves to maintain the integrity of the circulatory system. When blood vessel injury occurs, physiological haemostasis is triggered when vascular integrity is compromised.

For haemostasis to take place, vasoconstrictors such as thromboxane and epinephrine are released and stimulates vascular constriction, limiting blood supply to the injured area; this is the fist mechanism of haemostasis. Thrombocytes must adhere to exposed collagen fibers. They do so by releasing chemicals that make them sticky. At the same time thromboxane A2 recruits more thrombocytes to the area to for a loose temporary platelet plug …show more content…
These pathways are: intrinsic and extrinsic. The intrinsic pathway constituents lead to the conversion of factor X, the two pathways converge at this clotting factor to form the common pathway of blood coagulation, in order to form a clot. Both pathways contain different proteins known as clotting factors. Tissue factor is released when injury to the vessel has occurred, this initiates the extrinsic pathway. This starts a cascade of events, that causes clotting factors to activate, this is known as the coagulation