Which substance from the blood accumulates to form a clot?

Platelets are the primary component from the blood that accumulates to form a clot. When a blood vessel is damaged, platelets quickly adhere to the site of injury, becoming activated in the process. They release chemical signals that recruit even more platelets to the area, creating a sticky mass that helps seal the wound. This process is known as hemostasis and is vital for preventing excessive bleeding.

While white blood cells play a crucial role in the immune response and can contribute to inflammation during the healing process, they do not directly participate in the formation of blood clots. Plasma is the liquid component of blood that transports various substances, including nutrients and waste, but it does not itself form clots. Red blood cells are responsible for oxygen transport and are also involved in clotting, but they primarily become trapped within the clot rather than initiating its formation. Therefore, the involvement of platelets is key to the clotting mechanism.