Portal circulation, also known as the hepatic portal system, is a functional component of hepatic circulation. It is the circulation of nutrient-rich blood between the gut and liver. The portal vein is the main vessel of the portal venous system (PVS), which carries blood from organs in the abdomen to the liver. The portal vein drains almost all of the blood from the digestive tract and empties directly into the liver. This enables the liver to remove any harmful substances that may have been digested before the blood enters the systemic circulation. The hepatic portal system is about 8 cm long trunk of the vena portae, which arises behind the pancreas. The collection area of the hepatic portal system includes the stomach, pancreas, spleen, and intestines. Blood from these organs is rich in nutrients but poor in oxygen. Therefore, in addition to the functional circulation, systemic circulation must be introduced into the liver. The systemic circulation is supplied by the proper hepatic artery. In case of obstruction of the hepatic circulation or some of the veins of the portal system, functional connections to the body circulation are created, which are able to ensure the drainage of blood from the v. Portae system. These functional joints are called portocaval anastomoses, and their spread is an important diagnostic feature of so-called portal hypertension.