How does blood return to the heart after circulating through the body?

The return of blood to the heart after it has circulated through the body primarily occurs via the vena cava. This large vein carries deoxygenated blood from the body back to the right atrium of the heart. The superior vena cava brings blood from the upper body, while the inferior vena cava collects blood from the lower parts. Once the right atrium receives this blood, it passes through the tricuspid valve into the right ventricle, where it is then pumped to the lungs for oxygenation.

Other options, while related to the cardiovascular system, serve different purposes. The tricuspid valve functions as a one-way valve between the right atrium and ventricle but does not have a role in collecting blood. The pulmonary vein carries oxygenated blood from the lungs to the left atrium of the heart, and the aorta is tasked with distributing oxygen-rich blood from the heart to the body after it has been pumped from the left ventricle. Thus, the vena cava is the correct answer as it specifically facilitates the return of blood to the heart from systemic circulation.