What is a portal system?
1 Answer
A portal system is defined as a vascular arrangement in which blood from the capillaries of one organ is transported to the capillaries of another organ by connecting veins.
Explanation:
In the circulatory system of animals a portal venous system occurs when a capillary bed pools into another capillary bed through veins, without first going through the heart. Both capillary beds and the blood vessels that connect them are considered part of the portal venous system.
Examples of such systems include the hepatitic portal system, the hypophyseal portal system and the renal portal system in non-mammals.
The significance of such a system is that it transports products of one region directly to another region in relatively high concentrations. If the heart were involved in the blood circulation between those two regions, those products would be spread around the rest of the body.
The portal venous system is responsible for directing blood from parts of the gastrointestinal tract to the liver. Substances absorbed in the small intestine travel first to the liver for processing before continuing to the heart.
