hemosztázis

Hemostasis refers to the physiological process that stops bleeding. It is a complex and tightly regulated cascade involving blood vessels, platelets, and coagulation factors. When a blood vessel is injured, the first response is vasoconstriction, narrowing the vessel to reduce blood flow. This is followed by platelet activation and aggregation, forming a temporary plug at the site of injury.

The coagulation cascade then kicks in, a series of enzymatic reactions involving numerous clotting factors. This cascade culminates in the formation of fibrin, a protein that reinforces the platelet plug, creating a stable clot. This clot seals the damaged vessel and prevents further blood loss.

Once the vessel wall has healed, the clot is broken down through a process called fibrinolysis. This ensures that blood flow is restored and the circulatory system remains clear. Hemostasis is crucial for survival, preventing excessive blood loss from injuries. Disruptions in hemostasis can lead to either excessive bleeding (hemorrhage) or inappropriate clot formation (thrombosis).