Which vein returns blood to the right atrium from parts of the body below the diaphragm?

• A. Superior Vena Cava
• B. Pulmonary Vein
• C. Inferior Vena Cava
• D. Pulmonary Artery

Answer: (C)

Blood returning to the right atrium from parts of the body below the diaphragm travels via the inferior vena cava. This large vein collects deoxygenated blood from the lower body—the legs, pelvis, and abdomen—and also receives hepatic venous drainage from the liver as it ascends. The inferior vena cava delivers this blood directly into the right atrium, supplying the heart’s right side for the next step in circulation. For contrast, blood from above the diaphragm uses the superior vena cava, while the pulmonary veins return oxygenated blood to the left atrium and the pulmonary arteries carry blood from the right ventricle to the lungs.