AEMCA Practice Exam

Which blood components are responsible for clotting?

1. Red blood cells

2. Platelets

3. White blood cells

4. Lymphocytes

The correct answer is: Platelets

Platelets are the blood components primarily responsible for clotting. When there is damage to a blood vessel, platelets quickly gather at the injury site to initiate the clotting process. They adhere to the exposed tissue and each other, forming a temporary 'platelet plug' that helps stop the bleeding. This action is critical in the hemostatic process, as platelets also release chemicals that further facilitate the recruitment of more platelets and the activation of clotting factors, leading to the stabilization of the clot through the conversion of fibrinogen to fibrin. Red blood cells are primarily involved in the transport of oxygen and carbon dioxide and do not play a direct role in clot formation. White blood cells are part of the immune system and are involved in defense against infections, whereas lymphocytes, a type of white blood cell, specifically target viral infections and other immune responses rather than participating in the clotting mechanism. Thus, while all these components play vital roles in maintaining health, it is platelets that are specifically responsible for initiating and regulating the clotting process.