fibrín
Fibrin is a protein that plays a crucial role in blood clotting. It is formed from a precursor protein called fibrinogen, which is found in the blood plasma. When an injury occurs to a blood vessel, a cascade of reactions is initiated, leading to the activation of an enzyme called thrombin. Thrombin then cleaves fibrinogen, converting it into fibrin monomers. These monomers then spontaneously polymerize to form a mesh-like network. This fibrin mesh traps blood cells, such as red blood cells and platelets, forming a blood clot. The clot stops bleeding and allows the damaged tissue to begin healing. Fibrin is essential for hemostasis, the process by which bleeding is stopped. Without functional fibrin, even minor injuries could lead to excessive blood loss. The breakdown of fibrin, a process called fibrinolysis, is also important for restoring blood flow after healing has occurred. This is primarily carried out by an enzyme called plasmin. Disorders affecting fibrinogen or the enzymes involved in its conversion to fibrin can lead to either excessive bleeding or an increased tendency to form unwanted clots.