Question

The renal portal system of vertebrates is significant for

• A. Elimination of excess fats by kidneys
• B. Removing nitrogenous wastes in kidneys
• C. Supplying food to the kidneys
• D. Draining blood from the kidney

Answer 1

The correct option is B Removing nitrogenous wastes in kidneys

When the vein of any organ of the body does not open in the caval vein or heart but it divides into capillaries in any other organ and its blood is transported by a vein of that other organ to heart then this type of system is called Portal system. It is of three types- Renal portal system, Hepatic portal system, Hypophysial portal system. The renal portal system comprises of veins which collect blood from posterior parts of body and legs and combines to form a renal portal vein. This vein goes into kidney and divides into capillaries. Kidneys separate nitrogenous wastes from this blood. This partly purified blood is now transported to the heart. This system is present in frog but absent in mammals.

So, the correct answer is option B.