Which blood vessels are responsible for carrying blood back to the heart?

Veins are the blood vessels responsible for carrying blood back to the heart. They play a crucial role in the circulatory system by returning deoxygenated blood from the tissues to the heart, where it can then be pumped to the lungs for oxygenation. The structure of veins, which includes valves that prevent backflow, and their capacity to hold larger volumes of blood, allows them to effectively fulfill this role.

In contrast, arteries are responsible for carrying blood away from the heart, typically delivering oxygen-rich blood to the body. Capillaries serve as the sites of exchange between blood and tissues, facilitating the transfer of oxygen, carbon dioxide, nutrients, and waste products, but they do not perform the function of returning blood to the heart. Arterioles are smaller branches of arteries that lead to capillaries and also do not carry blood back to the heart. Therefore, veins are uniquely structured and functionally adapted for the task of returning blood to the heart in the circulatory process.