Sphincter of Oddi
The sphincter of Oddi, abbreviated as SO, is a muscular valve that in some animals, including humans, controls the flow of digestive juices through the ampulla of Vater into the second part of the duodenum. It is named after Ruggero Oddi. The sphincter of Oddi is relaxed by the hormone cholecystokinin via vasoactive intestinal peptide.Opiates may cause spasms of the sphincter of Oddi, leading to increased serum amylase levels.Other animals
In many mammals, the smooth muscle around the ampulla of Vater does not form a sphincter.History
The sphincter was described for the first time by Ruggero Oddi when he was a young student in 1887. This description followed extensive research into the physiology of dogs and detailed histological examinations of humans and many other species.
