This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
[{'content': 'True about valves in poal venous system? \nSelect and explain. \nA. Present at the junction of superior mesentric aery with the splenic aery, B. Within the poal vein only, C. The whole system is valveless, D. In the intrahepatic poion of poal vein.', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The whole system is valveless Venous valves help in unidirectional blood flow in veinsThe number of valves is greatest below the knee and decrease in number in the more proximal veins.Valveless veins or venous sytem are- Inferior vena Cava- Common iliac veins- Poal venous system- Cranial sinuses', 'role': 'assistant'}]