Physiology of primary hemostasis from A to Z

Primary haemostasis represents all the phenomena leading to the initial sealing of a vascular breach by the formation of a clot consisting essentially of platelets. Thus damage to the vascular endothelium a thromboresistant surface will lead to vasoconstruction and the platelets will come into contact with the thrombogenic components of the subendothelium. At present knowledge of the processes involved in primary haemostasis is extremely precise at the biochemical pharmacological and even molecular levels. It facilitates the diagnosis of constitutional disorders due to an impairment of one or more of the stages of primary haemostasis. Consequently therapeutic management is more appropriate. However a certain number of platelet abnormalities still escape precise diagnosis justifying the continuation of studies at the physiological or even pathophysiological level. It is the analysis of such abnormalities that may lead to considerable progress in the understanding of platelet physiology.