Question

Hepatic portal system starts from
A) Digestive system to liver
B) Kidney to liver
C) Liver to heart
D) Liver to kidney

Answer 1

Hint: It is a venous system that is important because it delivers blood to the center which is important for many chemical reactions concerned with the absorption of food and circulation.

Complete answer:
The hepatic portal system consists of veins beginning in the capillary beds of the stomach and intestine and terminating in the capillary beds of the Liver (liver sinusoids).
The hepatic portal system is a unique and complex vascular connection between the digestive tract and the liver. The veins draining the gastrointestinal tract do not directly join the inferior vena cava, the large vein that returns blood to the heart. Instead, the veins from the stomach and intestine enter the hepatic portal vein, which carries the products absorbed from the gastrointestinal tract directly to the liver. When the portal vein reaches the liver where it again breaks up into a capillary network (the liver sinusoids) to facilitate exchange between the blood and the hepatocytes.
Arterial blood coming from the aorta and venous blood coming directly from the gastrointestinal tract are the two sources of blood. Like other cells, the hepatocytes receive fresh arterial blood via the hepatic artery, which supplies oxygenated blood. The blood from parts of the gastrointestinal tract to the liver is carried out by the hepatic portal vein (a vein that carries blood from one capillary network to another is called a portal vein). Substances absorbed in the small intestine reach first to the liver for processing before continuing to the heart.

So, the correct answer is ‘Digestive system to liver’.

Note: When the blood pressure of the portal venous system is too high, it results in a condition known as Portal hypertension that often results in cirrhosis of the liver. High flow - low resistance system is the characteristic of normal hepatic circulation.