Veins return blood to the heart.

• A. False
• B. True
• C. Not always
• D. Not applicable

Answer: (B)

Veins are the vessels that return blood to the heart. In the systemic circulation they bring deoxygenated blood back to the right atrium via the superior and inferior vena cavae, while in the pulmonary circulation the pulmonary veins carry oxygenated blood back to the left atrium. The defining idea is the direction of flow: toward the heart. Veins have valves and operate under low pressure, with muscle contractions and breathing helping push blood back to the heart. So the statement is true.