Which component helps stop bleeding by forming a plug?

Which component helps stop bleeding by forming a plug?

• A. Plasma
• B. Platelets
• C. Red Blood Cells
• D. White Blood Cells

Answer: (B)

The key idea here is platelet-driven hemostasis. When a blood vessel is injured, exposed collagen and other factors trigger platelets to adhere at the site. They stick via von Willebrand factor, become activated, change shape, and release granules containing ADP and thromboxane A2. This recruits and activates more platelets, causing them to pile up and form a temporary platelet plug that rapidly reduces bleeding. This initial plug is what answers the question. Plasma is the liquid component carrying clotting factors for the later, more stable step of coagulation. Red blood cells mainly transport oxygen and contribute to clot structure passively, not by forming the plug. White blood cells are involved in immune responses and inflammation, not the primary plug formation. So the component that actually forms the plug to stop bleeding is platelets.

The key idea here is platelet-driven hemostasis. When a blood vessel is injured, exposed collagen and other factors trigger platelets to adhere at the site. They stick via von Willebrand factor, become activated, change shape, and release granules containing ADP and thromboxane A2. This recruits and activates more platelets, causing them to pile up and form a temporary platelet plug that rapidly reduces bleeding. This initial plug is what answers the question.

Plasma is the liquid component carrying clotting factors for the later, more stable step of coagulation. Red blood cells mainly transport oxygen and contribute to clot structure passively, not by forming the plug. White blood cells are involved in immune responses and inflammation, not the primary plug formation. So the component that actually forms the plug to stop bleeding is platelets.