Platelet Function Under Flow.

As vertebrates have evolved high-pressure, high-flow circulatory systems, an extraordinarily effective hemostatic system has developed alongside to protect these organisms from hemorrhage. More than a century's worth of evidence indicates that platelets are the blood cells chiefly responsible for maintaining hemostasis and causing thrombosis. Platelets are geared to monitor vascular integrity and effect hemostasis in the arterial circulation, as injuries to arteries (rather than veins) are much more likely to result in circulatory collapse and death. Furthermore, deployment of the hemostatic mechanism in the setting of vascular disease—particularly that caused by atherosclerosis—is largely responsible for the tremendous disease burden associated with vascular disease, being the culminating event in myocardial infarction and stroke. In this chapter, we review the characteristics of blood flow that influence platelet function and the cellular and molecular determinants that allow the platelets to carry out their hemostatic functions under flow. [ABSTRACT FROM AUTHOR]