Wound healing is characterized by an orderly sequence of events, which can be broadly classified into distinct phases (Fig. 4.1). These phases proceed in a systematic fashion with a high degree of integration, organization, and control. However, the various stages are not sharply delineated but overlap considerably, and factors affecting one phase have a stimulatory or inhibitory effect on the overall process [1]. Immediately following injury, platelets aggregate and release coagulation factors and growth factors that are important for hemostasis and initiation of the wound-healing process. A fibrin matrix is formed, which allows for cell migration on a scaffold within the wound site. Platelets adhere to the subendothelium that is exposed following injury. The process, referred to as platelet activation, induces changes in platelet structure and function that are necessary for coagulation to occur.