What are the vessels called that carry oxygenated blood back to the heart?

Veins are the vessels responsible for carrying oxygenated blood back to the heart, particularly from the lungs where blood acquires oxygen. This is an essential function in the circulatory system, as it ensures that oxygen-rich blood can be distributed throughout the body.

In the context of systemic circulation, oxygenated blood from the lungs is transported via pulmonary veins to the left atrium of the heart. After the blood has circulated through the body, it returns to the heart through veins, which are structured to handle this flow and include valves to prevent backflow.

It's also important to note that while arteries carry oxygenated blood away from the heart to the tissues, and capillaries facilitate the exchange of nutrients and gases at the cellular level, veins specifically serve the function of returning blood to the heart, completing the cycle of circulation. Similarly, venules are smaller vessels that collect blood from capillaries and join to form veins, but they do not perform the primary function of carrying oxygenated blood back to the heart on their own.