What is the hepatic portal system and how does it work?
The hepatic portal system refers to the route of blood flow through the liver. Several abdominal organs send blood to the liver for detoxification before it enters the general circulation. The stomach is a good example. We ingest substances on a daily basis that could prove to be harmful and toxic to our systems. This rerouting of blood to the liver attempts to rid it from these harmful substances before that blood enters the systemic circulation. The hepatic portal vein accomplishes this task.
After the blood leaves the liver it is then transported to the inferior vena cavae which empties into the right atrium of the heart. This completes the process of systemic venous return.
One reason this process is important is that the hepatic portal system acts to decrease blood glucose concentrations by removing glucose that would normally enter the circulation and storing it as glycogen in the liver.
The hepatic portal system (also known as the portal venous system) is the name for the collection of veins that make up the hepatic portal vein and its tributaries. It is responsible for moving the blood from different parts of the gastrointestinal tract to the liver. It is also responsible for the blood drainage from the spleen and pancreas.
It is important for the substances that are absorbed in the intestine to be filtered through the liver before it continues back to the heart, and this is part of the function of the hepatic portal system. Because of this system some drugs that are absorbed in the GI tract lose their effectiveness because they are metabolized by the liver so it is important for some drugs t be taken through the skin or under the tongue so it bypasses this system.