Question

Hepatic portal system is found in
(a)All mammals
(b)All amniotes
(c)All vertebrates
(d)Higher invertebrates
(e)None of these

Answer 1

Hint: Hepatic portal system is a network of veins that is responsible for the filtration of the blood that is ingested by the organism. This filtration of food is done by the liver. The hepatic portal system is found in amphibians.

Complete answer:
The hepatic portal system has a deep connection of veins around the intestine, stomach, spleen, and the liver in all mammals. The function of this system is to transport blood from the intestine and deliver it to the liver where detoxification occurs.
As blood around the intestine has absorbed all the contents present in the food, it will also contain poison or toxins that have been ingested along with food. These harmful chemicals cannot be released in the body, so they are first taken to the liver where these chemicals are broken down into simpler less toxic forms.
Once the blood is detoxified, it is carried to the heart which pumps this blood to the entire body.
The hepatic portal system consists of the hepatic portal vein, inferior mesenteric vein, superior mesenteric vein, and gastrosplenic vein. The superior mesenteric vein and the gastrosplenic vein come together to give rise to the hepatic portal vein.
So, the correct option is ‘All mammals’.

Note: -An alcoholic person has a very damaged liver because the liver is constantly in exposure to toxic alcohol in order to detoxify it.
-Another portal system is found between the hypothalamus and anterior pituitary (adenohypophysis) known as the hypophyseal portal system.
-Through this portal system, hypothalamic hormones are released which then reach the pituitary and control its functioning.