What is the function of the venae cavae in the circulatory system?

The venae cavae serve a crucial role in the circulatory system by returning oxygen-depleted blood from the body back to the heart. Specifically, the superior vena cava collects blood from the upper body, while the inferior vena cava collects blood from the lower body. This deoxygenated blood then enters the right atrium of the heart, where it is subsequently pumped to the lungs for oxygenation. This process is essential for maintaining the efficient functioning of the circulatory system as it ensures that the blood is continually cycled to pick up oxygen and release carbon dioxide.

The other options refer to functions that are not associated with the venae cavae. The supply of oxygen-rich blood is primarily the responsibility of the arteries, particularly the pulmonary veins and the aorta. Nutrient transport is chiefly conducted by the blood vessels associated with the digestive system, while hormone distribution is managed by the bloodstream and various endocrine glands.