Portal and hepatic veins

Portal vein:  the main vessel of the portal venous system (PVS), which drains the blood from the gastrointestinal tract, gallbladder, pancreas, and spleen to the liver.

Hepatic vein: blood vessels that return low-oxygen blood from your liver back to the heart. The veins are key players in the supply chain that moves the blood that delivers nutrients and oxygen to every cell in your body.