<prompt> True statement regarding portal venous system:Whole system is valve lessValves are present at the junction of superior mesenteric artery and splenic arteryValves are present in the intrahepatic systemThere are about 10-12 valves along the entire course  <response>: Ans. a Whole system is valve lessRef BDC 4th ed. Vol. 11268-71, Grays 39th ed 1218-19 In adults, the portal vein and its tributaries have no valves. In fetal life and for a short postnatal period valves are demonstrable in its tributaries, but they usually gets atrophied. Rarely some persist in an atrophic form into adulthood. 