When it is said that platelets are suspended in blood plasma, it means that platelets are present in the fluid component of blood known as plasma. Plasma is a yellowish liquid that makes up about 55% of blood volume and is composed of water, proteins, hormones, nutrients, waste products, and other substances. Platelets, also called thrombocytes, are small colorless cells that are responsible for blood clotting. They float freely in the plasma and become activated when there is an injury or damage to blood vessels, helping to form blood clots to prevent excessive bleeding.
