The response to vascular injury involves attachment and aggregation of
platelets, coupled with initiation of the coagulation cascade. These
inter-related processes ensure that the vessel injury is rapidly block
ed with an aggregated clump of platelets that is then stabilized by a
crosslinked fibrin matrix. Initial adherence relies on the ability of
the platelet adhesion receptors to bind subendothelial matrix molecule
s. Platelet activation then results in the expression of high affinity
integrin receptors on the cell surface that bind soluble ligands, all
owing platelets to aggregate and form a haemostatic plug.