Adhesive interactions in hemostasis

Adhesion molecules and adhesive interactions play a critical role in the process of hemostasis. A vascular rent requires a patch, and this patch must be provided from constituents of the cellular and fluid phases of flowing blood, constituents that must not interfere with this flow under unperturbed conditions. Platelets, the cellular elements of the patch, are inert until they encounter conditions that trigger their activation. In response to injury they undergo a rapid and dramatic change both in shape and in their surface characteristics, a change that allows them to become both the nidus and the stimulus for the precipitation of a meshwork of fibrin. The interactions between platelets and exposed collagen in the damaged vessel wall, plasma and platelet von Willebrand factor, and plasma and platelet fibrinogen can all be considered 'adhesive interactions'.