Hemostasis – compendium for students

Abstract

Hemostasis is one of many well-known systems that ensure a constant conditions of the organism's internal environment. This process is usually divided into two main stages: coagulation and fibrinolysis. Both of them occur simultaneously and under physiological conditions they are in dynamic equilibrium. There are primary and secondary hemostasis. The primary hemostasis leads to the formation a platelet clot that forms almost directly after a blood vessel has been ruptured. In the other hand, the secondary hemostasis is the activation of coagulation, which leads to the strengthening of the platelet plug through the fibrin network formation as a result of the polymerization of the soluble plasma protein fibrinogen. The key role in hemostasis plays the interaction of platelets – which are the smallest non nucleated blood cells that are formed from the cytoplasm of megakaryocytes, and plasma coagulation factors with vascular endothelial cells and subendothelial tissues. In this report it is decribed the process of physiological hemostasis, especially the newer concept of blood coagulation.