Hepatic Portal System - Essentials
Hepatic portal system
- A special circulation system that transports venous blood from the digestive organs to the liver.
- Transports blood from the stomach, spleen, pancreas, and small and large intestines to the liver. This distinct circulatory pathway exists to allow the liver to metabolize nutrients and toxins from blood that leaves the digestive organs.
Primary tributaries of the hepatic portal vein:
Superior mesenteric vein drains tissues of the right side of the abdomen
Splenic vein drains structures on the left side of the abdomen.
- Merges with superior mesenteric vein to form hepatic portal vein
- Drains Inferior mesenteric vein
Inferior mesenteric vein drains tissues of the lower left side of the abdomen.
Additional information:
Hepatic vein
- Drains blood from liver to inferior vena cava
- Helps secure liver in place
Clinical Correlations:
- Portal hypertension occurs when the hepatic portal vein becomes blocked.
- Blood clots can cause obstruction of the hepatic portal vein, but, more commonly, portal hypertension is the result of cirrhosis, in which the liver tissue is replaced by scar tissue in response to damage from a variety of causes, including chronic alcohol intoxication or hepatitis C.
- As blood flow is obstructed, blood pressure in the hepatic portal system increases, and venous engorgement occurs. These enlarged veins form thin-walled varices, which are susceptible to trauma.
- Rupture of esophageal varices, which form at the junction of the stomach and esophagus, can cause fatal gastrointestinal hemorrhage.