Which type of blood vessel carries blood back to the heart?

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

Answer: (B)

Veins carry blood back to the heart. They are the low-pressure vessels that return blood from the body, aided by valves that prevent backflow as the blood moves upward or against gravity. Blood collected from the capillaries in tissues drains into small veins called venules, which then join larger veins that funnel blood toward the heart. Most of this returning blood is deoxygenated, though there are exceptions like the pulmonary veins, which bring oxygenated blood from the lungs to the heart. Arteries do the opposite, carrying blood away from the heart under higher pressure, while capillaries are the tiny vessels where exchange of gases, nutrients, and wastes occurs. Venules are simply the smaller components of the venous system, leading to the larger veins.