Platelet activation is a crucial process in the body's response to injury. When a blood vessel is damaged, platelets, which are small cell fragments in the blood, quickly adhere to the site of injury. This adhesion is triggered by exposure to collagen and other substances in the damaged tissue, leading to the activation of the platelets. Once activated, platelets change shape and release chemical signals that attract more platelets to the site. This aggregation forms a temporary platelet plug that helps stop bleeding. Additionally, activated platelets release substances that promote healing and initiate the coagulation cascade, further stabilizing the clot.