Which vessel returns deoxygenated blood to the heart from the systemic circulation?

• A. Pulmonary artery
• B. Aorta
• C. Superior vena cava
• D. Inferior vena cava

Answer: (C)

Deoxygenated blood from the systemic circulation returns to the heart through the veins that enter the right atrium. The major vein bringing blood from the upper body is the superior vena cava, which drains into the right atrium. The inferior vena cava serves the lower body, also delivering deoxygenated blood to the right atrium. The pulmonary artery, by contrast, carries blood away from the heart to the lungs, and the aorta carries oxygenated blood from the heart to the body. So, the vessel that returns deoxygenated blood to the heart from the systemic circulation is the superior vena cava.