The hepatic veins are blood vessels that carry deoxygenated blood away from the liver. They collect blood from the liver's sinusoids, which are small capillary-like structures where nutrient and waste exchange occurs. The hepatic veins then transport this blood to 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 drains 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.