Valve of heister is seen in ?: (A) Cystic duct, (B) Common bile duct, (C) Common hepatic duct, (D) Pancreatic duct
Answer is A. The mucous membrane of the cystic duct forms a series of 5-12 crescentic folds, arranged spirally to form the so called spiral valve of Heister. This is not a true valve.