Platelets are small disc shaped cells that are formed in the bone marrow. Seventy to eighty percent of platelets circulate in the bloodstream while the remainders are stored in the spleen. The average platelet lives about 10 days.
Platelets play a crucial role in helping blood to clot.
A defect in any one of these functions will result in an increased tendency to bleed. Platelets attach to the lining of the injured blood vessel and begin the first phase of the clotting process. After platelets initially begin to adhere to the wall of an injured blood vessel, additional platelets are called to the site of injury. The platelets begin to aggregate or stick to each other, forming a platelet plug. Activation and Secretion Granules inside the platelets function to store and release specific proteins that help platelets aggregate at the site of blood vessel injury.