Fig. 5.

Formation of an optimal platelet plug. Vascular injury produces a hemostatic response that can be too aggressive (leading to occlusion and ischemia), inadequate (leading to further bleeding), or optimal. This model suggests that an optimal response varies in detail (hence, a range of normal), but is best viewed as a response that results in hemostasis with a minimum of blood loss and an avoidance of unwarranted vascular occlusion. In the setting of a vascular wall disease such as atherosclerosis, the rapid accumulation of platelets on top of a ruptured plaque represents an escape from normal restraints.