True statement regarding poal venous system is?
Whole system is valve less REF: BDC 4th edition vol II p. 268-71, Gray's Anatomy 39th edition p. 1218 In adults, the poal vein and its tributaries have no valves. In fetal life and for a sho postnatal period valves are d emonstrable in its tributaries, but they usually atrophy. Rarely some persist in an atrophic form into adulthood.