koagulatsioonisüsteemi

The coagulation system, also known as the hemostasis system, is a complex network of proteins and cells in the blood that work together to stop bleeding. When a blood vessel is injured, the coagulation system is activated to form a clot, which seals the wound and prevents excessive blood loss. This process involves a cascade of enzymatic reactions where inactive precursor proteins, called zymogens, are converted into active enzymes. These active enzymes then activate the next protein in the cascade, ultimately leading to the formation of fibrin. Fibrin is a protein that forms a mesh-like structure, trapping blood cells and platelets to create a stable clot.

The coagulation system can be broadly divided into two main pathways: the intrinsic and extrinsic pathways. Both pathways converge on a common pathway, which culminates in the activation of thrombin. Thrombin is a key enzyme that converts fibrinogen, a soluble protein in plasma, into insoluble fibrin. Platelets also play a crucial role by adhering to the site of injury and aggregating to form a platelet plug, which is then reinforced by the fibrin clot. The entire process is tightly regulated to prevent excessive clotting, which could lead to thrombosis, or insufficient clotting, which can result in bleeding disorders. Anticoagulant proteins and enzymes are present to control and break down clots once they are no longer needed.