Microcytes are the smallest blood cells. It is spherical, ovoid, rod-shaped and without a nucleus. Their diameter is 1-4 µm. Their cytoplasm contains pinocytic cavities and contractile cavities. The number of platelets per cubic milliliter of blood is 1.5-3.0 lakhs. But its number is more in diseased body. Their average lifespan is 8-12 days. It contains proteins and phospholipids called cephalin. It is stored only in the spleen. They originate from megakaryocyte cells in the bone marrow and are destroyed in the liver and spleen. About 200 billion (20 thousand crore) molecules are produced every day. Glycoproteins located in the molecular membrane bind to vascular lesions and large amounts of phospholipids are released from the membrane. It accelerates blood clotting.