Platelets are released from megakaryocytes in the bone marrow and circulate for 5 to 10 days before being cleared by the cells of the reticuloendothelial system. They play a critical role in haemostasis, with key features being (1) adhesion—when the wall of a blood vessel is damaged, platelets adhere to exposed collagen and other components of the subendothelium via the glycoprotein Ib receptor and other adhesive receptors; followed by (2) activation—release of thrombin, adenosine diphosphate, and arachidonic acid, which is converted by a cascade of enzymes into platelet activating agents including thromboxane A...