In human body, ______ are primarily used to stop bleeding by forming clots.

Platelets, also known as thrombocytes, are small, colorless cell fragments present in the blood that play a vital role in hemostasis, the process by which the body stops bleeding. When a blood vessel is damaged, platelets quickly move to the injured area and attach themselves to the exposed surface. They become activated and release chemicals that attract and activate additional platelets. These platelets then stick together to form a platelet plug, which temporarily seals the damaged blood vessel. Platelets also support the formation of a fibrin clot, which strengthens the plug and helps stop bleeding. Therefore, platelets are primarily responsible for initiating and supporting blood clot formation.