hemostàsia

Hemostasia, also known as hemostasis, is the physiological process that stops bleeding. It is a complex cascade involving blood vessels, platelets, and coagulation proteins. When a blood vessel is injured, the first response is vasoconstriction, a narrowing of the vessel to reduce blood flow. Immediately following this, platelets adhere to the site of injury and aggregate, forming a temporary platelet plug. This plug acts as a plug to stem the flow of blood. Concurrently, the coagulation cascade is activated. This is a series of enzymatic reactions involving various clotting factors in the blood. The ultimate goal of the coagulation cascade is to form fibrin, a protein that reinforces the platelet plug and creates a stable clot. This clot seals the injured vessel and prevents further blood loss. Once the vessel has healed, a process called fibrinolysis begins, which breaks down the clot and restores normal blood flow. Disruptions in hemostasis can lead to excessive bleeding (hemorrhage) or unwanted clot formation (thrombosis).