Question

The venous system of frog differs from that of rabbit in the presence of

• A. Hepatic portal system
• B. Renal portal system
• C. Hepatic vein
• D. Three vena cava

Answer 1

The correct option is B Renal portal system

The venous system of frog differs from that of rabbit in the presence of renal portal system. The capillaries receiving deoxygenated blood from the hind limb of frog join together and form a femoral vein and a sciatic vein. The femoral vein arising from the outer lateral side in the thigh region runs anteriorly and divides into two braches : An outer external iliac vein and an inner pelvic vein. The sciatic vein arising by the union of capillaries in the major part of the hind limb muscles runs anteriorly and dorsally to enter the body cavity where it joins with the external iliac vein and forms a large renal portal vein. One or two dorsolumbar veins join the renal portal vein on the outer margin of the kidney. These veins drain blood from the dorsal body wall especially of the lumbar region. In female frog an oviducal vein also opens in the renal portal vein. The renal portal vein enters the kidney from the outer margin and divides into a large number of capillaries therein.