Portal vein

Nicole Wendler holds a PhD in biology in the field of oncology and immunology. As a medical editor, author and proofreader, she works for various publishers, for whom she presents complex and extensive medical issues in a simple, concise and logical manner.

More about the experts All content is checked by medical journalists.

The (liver) portal vein collects the venous, deoxygenated blood from the digestive organs and brings it to the liver. This is where the nutrients from food, drugs and toxins absorbed in the digestive tract are metabolized. Here you can find out everything you need to know about the portal vein!

What is the portal vein?

Strictly speaking, there are two portal veins (Vena portae) in the human body: the hepatic portal vein (Vena portae hepatis) and the pituitary portal vein (Vena portae hypophysiales). The short term portal vein usually means that of the liver. It is one of the veins and brings oxygen-poor blood from the abdomen to the liver. Its length is about six centimeters and it lies horizontally just behind the pancreas.

Collection point for blood from the abdomen

The portal vein of the liver is created by the union of the splenic vein and the superior intestinal vein. In its course, further veins from the unpaired abdominal and pelvic organs flow into: left and right gastric vein, pyloric vein (vein of the gastric porter), gallbladder vein, lower intestinal vein (first opens into the splenic vein) and veins from the abdominal wall around the navel.

The portal vein of the liver collects the blood from these veins and delivers it to the liver: As a central metabolic organ, it processes the nutrients from food that have been absorbed into the blood in the digestive tract. Also absorbed drugs and toxins as well as breakdown products from the spleen are metabolized in the liver.

The portal vein enters the liver at the hepatic portal - a point on the underside of the organ where the hepatic artery joins, among other things. Inside the liver, the portal vein splits into two main branches and then into ever finer branches. The oxygen-poor, nutrient-rich blood that is carried along mixes in the capillaries of the liver (liver sinusoids) with the oxygen-rich blood that is brought up by the fine branches of the hepatic artery. Two capillary networks are connected via the portal vein: that of the digestive organs and that of the liver.

The portal vein circuit

You can read everything you need to know about this secondary circulation of the great blood circulation in the portal vein circulation.

Discomfort around the portal vein

With portal hypertension, the pressure in the portal vein is permanently increased to over 12 mmHg (normally it is three to six mmHg). The cause is a flow obstacle in front of, in or behind the liver. Examples of a prehepatic block (flow obstruction in front of the liver) are portal vein thrombosis and tumors (e.g. of the pancreas, stomach, intestines) that obstruct the flow. An intrahepatic block (flow obstruction within the liver) can be due to liver cirrhosis, chronic liver inflammation (hepatitis) or liver tumors. Chronic pericardial inflammation and a leaky tricuspid valve (heart valve between the right atrium and right ventricle) can lead to portal hypertension as a posthepatic block (flow obstacle behind the liver).

Other health problems in the area of ​​the portal vein include injuries, malformations and benign and malignant neoplasms.

Tags:  fitness pregnancy birth anatomy