Photomicrograph of two megakaryocytes forming platelets from their cytoplasmic extensions.
Click here to view a video clip of the primary hemostastatic process

The Role of Platelets

Platelets play a major role in hemostasis. They maintain surveillance of blood vessel continuity, filling small gaps that can form between endothelial cells that make up the lining of the vessel wall. They form the primary hemostatic plug when vessel injury occurs, and secrete growth factors to stimulate healing after injury.¹

Disc-shaped and inert in the environment of the normal endothelium, platelets respond to injury by forming a hemostatic plug.¹ This process follows a sequence of four steps. Click on the following to learn more:

• Platelet Adhesion
  
• Platelet Activation
  
• Platelet Aggregation
  
• Platelet Secretion

For information on secondary hemostasis or coagulation, click here.


Reference