See Also: prothrombin(encyclopedia)
Prothrombin(medicine)
prothrombin(dictionary)
prothrombin test(medicine)
prothrombin deficiency(medicine)
prothrombin accelerator(medicine)
Prothrombin time(medicine)
prothrombin and proconvertin test(medicine)
serum prothrombin conversion accelerator(medicine)
proserum prothrombin conversion accelerator(medicine)

prothrombin (sh)




Carbohydrate-protein compound in plasma essential to coagulation.

In response to bleeding, a complex series of clotting-factor interactions leads to its conversion by thromboplastin to thrombin, which transforms fibrinogen in plasma into fibrin. Fibrin and platelets combine to form a clot. Hemophilia is caused by a hereditary lack of one of the clotting factors. Vitamin K is needed to synthesize prothrombin, so conditions that impair the vitamin's absorption result in prothrombin deficiency and a tendency to prolonged bleeding.