How does blood gets coagulated on coming out from an injured vessel. How coagulation normally prevented uninjured vessels.
When a blood vessel is injured, the blood starts coming out of it. At that time, the thrombocytes clump together, break and release the coagulation-promoting substances called thromboplastin. Thromboplastin helps in the formation of the enzyme thrombokinase. This enzyme thrombokinase hydrolyses prothrombin in the plasma into thrombin. Thrombin catalyzes the hydrolysis of soluble fibrinogen in the plasma into insoluble fibrin. The fibrin precipitates as a network of fibers and traps many blood cells to form a red solid mass called a blood clot. The clot seals the wound in the blood vessel to stop bleeding. However, in uninjured tissues and blood vessels, thromboplastin does not get released. That is why coagulation is prevented in an uninjured vessel.
