Sphincter of Boyden
The sphincter of Boyden is a sphincter located in the common bile duct before it joins with the pancreatic duct to form the ampulla of vater. This sphincter controls the flow of bile into the pancreatic duct and it helps in filling up of the gallbladder with bile.
Structure
The sphincter of Boyden is a smooth muscle sphincter surrounding the common bile duct. It occurs just before the junction with the pancreatic duct, where the ampulla of Vater is formed. Occasionally, some fibres also surround the pancreatic duct.It is subdivided into two parts - pars superior and pars inferior. The pars inferior is the strongest component of the sphincter of Oddi complex.
Function
Its contractions regulate the passage of bile into the gall bladder or the duodenum.