Explain the role of the hepatic portal system and lymphatic system within the circulatory system

The hepatic portal vein is responsible in carrying blood to the liver from the spleen and the gastrointestinal tract. Another role is that the hepatic vein drains blood coming from the cystic veins as well as the inferior mesenteric gastric veins. Therefore, the hepatic vein is an important portal venous system in the human body and to the circulatory system in general. Meanwhile, the lymphatic system is composed of lymph nodes and lymph vessels that serve as a transport service of blood to the external environment.