Biology · Structural Organisation in Animals · NEET
The hepatic portal system connects the intestine and the liver. The hepatic portal vein carries blood coming from the intestine (full of absorbed food) to the liver first, before that blood returns to the heart. This is why the liver processes food nutrients right after a meal. NCERT states this special venous connection is present in frogs.
The renal portal system links the lower (posterior) parts of the body to the kidney. The renal portal vein carries blood FROM the hind region of the body INTO the kidney before that blood goes on toward the heart. So it delivers blood to the kidney, it does not drain blood away from it. NEET 2025 tested exactly this: renal system links kidney and the lower part of the body.
Both are portal systems (a vein between two organs), but they connect different organs. Hepatic portal system = liver and intestine (blood from intestine to liver). Renal portal system = kidney and lower body (blood from lower body to kidney). Easy rule: HEPATIC has the word for liver (hepato = liver), RENAL has the word for kidney (renal = kidney).
A normal vein carries blood straight back to the heart. A portal vein is different: it starts in capillaries of one organ and ends in capillaries of another organ, so blood passes through TWO capillary beds before reaching the heart. Because the blood goes through a second organ on the way, this special venous connection is called a portal system.
No. Humans (and mammals in general) have a hepatic portal system but do NOT have a functional renal portal system. The renal portal system is a feature of frogs and many lower vertebrates. This is a common NEET trap, so remember: frog has BOTH portal systems, humans have ONLY the hepatic one.
In frog, the Renal system is a special venous connection that acts to link:
Choose the correct statements regarding frog's anatomy: A. Hepatic portal system is the special venous connection between liver and intestine. B. There are twelve pairs of cranial nerves arising from the brain. C. The ureters and oviducts open separately into the cloaca in female frogs. D. Hind-brain consists of cerebellum, medulla oblongata and optic lobes. E. Sinus venosus joins the right atrium of heart.
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Two: the hepatic portal system (intestine to liver) and the renal portal system (lower body to kidney).
It carries nutrient-rich blood from the intestine to the liver, so the liver can process food nutrients before the blood returns to the heart.
The renal portal system is absent in humans. Humans keep only the hepatic portal system.
To the kidney. It brings blood from the lower parts of the body into the kidney before that blood continues toward the heart.
Portal systems are a favourite one-mark, high-yield topic. NEET 2025 and NEET 2026 both tested the exact organs each portal system links, so a single memorised line can win a direct mark.
