Hepatic veins are blood vessels that carry deoxygenated blood away from the liver. They collect blood from the liver's sinusoids, which are small blood vessels that allow for the exchange of nutrients and waste products. The hepatic veins then drain into the inferior vena cava, a large vein that returns blood to the heart. There are three main hepatic veins: the right, middle, and left hepatic veins. Each vein corresponds to a specific lobe of the liver. Proper functioning of the hepatic veins is essential for maintaining healthy liver function and overall circulation in the body.