Adhesion In the adhesion phase, platelets adhere to exposed collagen fibers at the site of vascular injury. This process is mediated by von Willebrand factor (vWF), which binds to both collagen and the platelet surface receptors.
Activation Once adhered, platelets become activated. This activation leads to a shape change from a smooth disc to a spiky form and the release of various granule contents, including ADP and thromboxane A2, which further promote platelet activation and recruit additional platelets to the injury site.
Aggregation During aggregation, activated platelets bind to each other through fibrinogen bridges formed by the glycoprotein IIb/IIIa receptors on their surfaces. This results in the formation of a stable platelet plug.
