Which structure carries blood back to the heart and contains one-way valves?

Which structure carries blood back to the heart and contains one-way valves?

• A. Veins
• B. Arteries
• C. Capillaries
• D. Aorta

Answer: (A)

Venous return relies on vessels that move blood back toward the heart and keep it moving in one direction. Veins have one-way valves inside their walls that prevent backflow as blood flows against gravity, especially from the lower body. These valves work with muscle contractions and breathing changes to push blood upward toward the heart. Arteries carry blood away from the heart and generally don’t have valves along their length (valves are located at the heart junctions, not within the arterial network). Capillaries are tiny exchange vessels and don’t contain valves. The aorta is the main artery leaving the heart and also lacks internal valves along its course. Thus, the structure that returns blood to the heart and contains one-way valves is veins.

Venous return relies on vessels that move blood back toward the heart and keep it moving in one direction. Veins have one-way valves inside their walls that prevent backflow as blood flows against gravity, especially from the lower body. These valves work with muscle contractions and breathing changes to push blood upward toward the heart.

Arteries carry blood away from the heart and generally don’t have valves along their length (valves are located at the heart junctions, not within the arterial network). Capillaries are tiny exchange vessels and don’t contain valves. The aorta is the main artery leaving the heart and also lacks internal valves along its course. Thus, the structure that returns blood to the heart and contains one-way valves is veins.