Which part of the vasculature carries blood back to the heart?

Veins are the vessels specifically responsible for returning blood to the heart. They are equipped with one-way valves that prevent backflow, ensuring that blood flows in the correct direction towards the heart, even against the force of gravity in parts of the body that are lower than the heart. The walls of veins are thinner and less muscular compared to arteries, which allows them to accommodate varying volumes of blood and to act as a reservoir.

In contrast, arteries carry blood away from the heart, distributing it throughout the body, while capillaries are the smallest blood vessels where the exchange of oxygen, carbon dioxide, nutrients, and waste occurs between blood and tissues. Venules, which are small vessels that collect blood from capillaries, transport blood toward veins but do not directly return blood to the heart themselves. Together, these different parts of the vascular system work harmoniously, but when specifically looking at the role of returning blood to the heart, veins are the key players.