Platelets and Hemostasis

Platelets are circulating, anucleate cells derived from megakaryocytes. While platelets were originally thought to have a role only in primary hemostasis, more recently, these cells have been discovered to participate in a wide variety of pathways, including hemostasis, immunology, wound healing, and cancer biology. Dependent on their RNA and protein expression profiles, platelets may also display various phenotypes that play a part in the pathophysiology of specific diseases, such as sepsis, cancer, and autoimmune conditions. In order to understand platelets and their roles within the body, it is important to understand the origin and development of the platelet, starting from the hematopoietic stem cell. In this article, we provide a bird's-eye view of the increasingly complex megakaryocyte-platelet axis and its various roles in the body.