The hepatic portal system is a unique circulatory system that connects two systems of capillary beds: one in sinusoidal area of the liver and the other in the wall of the small intestine and spleen. The portal vein receives drainage from the gallbladder, spleen, pancreas, stomach, and small and large intestines. It is the only mammalian vein which starts with and ends in a capillary network.

The hepatic portal vein carries blood from organs in your abdomen (belly) to your liver.