In terms of blood circulation, veins carry blood:

In the context of blood circulation, veins are responsible for carrying blood back to the heart. This process is crucial because it allows the heart to then pump that deoxygenated blood to the lungs for oxygenation. The unique structure of veins, including thinner walls and valves, aids this return journey by preventing backflow and accommodating lower pressure compared to arteries.

In contrast, arteries carry blood away from the heart, delivering oxygen-rich blood to various parts of the body. The notion that veins carry blood only to the lungs is misleading since veins are involved in returning blood from all body tissues back to the heart, not exclusively to the lungs. Additionally, veins do not transport blood directly to arteries; instead, they function in the circulatory system to ensure that deoxygenated blood is returned efficiently to the heart, which is crucial for maintaining proper blood flow and overall physiological balance.