Common bile duct
Encyclopedia
The common bile duct is a tube-like anatomic structure in the human gastrointestinal tract
. It is formed by the union of the common hepatic duct
and the cystic duct
(from the gall bladder). It is later joined by the pancreatic duct
to form the ampulla of Vater. There, the two ducts are surrounded by the muscular sphincter of Oddi
.
When the sphincter of Oddi is closed, newly synthesized bile
from the liver is forced into storage in the gall bladder. When open, the stored and concentrated bile exits into the duodenum
. This conduction of bile is the main function of the common bile duct. The hormone cholecystokinin
, when stimulated by a fatty meal, promotes bile secretion by increased production of hepatic bile, contraction of the gall bladder, and relaxation of the Sphincter of Oddi.
Several problems can arise within the common bile duct. If clogged by a gallstone
, a condition called choledocholithiasis can result. In this clogged state, the duct is especially vulnerable to an infection called ascending cholangitis
. Very rare deformities of the common bile duct are cystic dilations (4 cm), choledochoceles (cystic dilation of the ampula of Vater (3–8 cm)), and biliary atresia
.
Gastrointestinal tract
The human gastrointestinal tract refers to the stomach and intestine, and sometimes to all the structures from the mouth to the anus. ....
. It is formed by the union of the common hepatic duct
Common hepatic duct
The common hepatic duct is the duct formed by the convergence of the right hepatic duct and the left hepatic duct . The common hepatic duct then joins the cystic duct coming from the gallbladder to form the common bile duct...
and the cystic duct
Cystic duct
The cystic duct is the short duct that joins the gall bladder to the common bile duct. It usually lies next to the cystic artery. It is of variable length...
(from the gall bladder). It is later joined by the pancreatic duct
Pancreatic duct
The pancreatic duct, or duct of Wirsung , is a duct joining the pancreas to the common bile duct to supply pancreatic juices which aid in digestion provided by the "exocrine pancreas"...
to form the ampulla of Vater. There, the two ducts are surrounded by the muscular sphincter of Oddi
Sphincter of Oddi
The sphincter of ampulla or sphincter of Oddi is a muscular valve that controls the flow of digestive juices through the ampulla of Vater into the second part of the duodenum. It is named after Ruggero Oddi...
.
When the sphincter of Oddi is closed, newly synthesized bile
Bile
Bile or gall is a bitter-tasting, dark green to yellowish brown fluid, produced by the liver of most vertebrates, that aids the process of digestion of lipids in the small intestine. In many species, bile is stored in the gallbladder and upon eating is discharged into the duodenum...
from the liver is forced into storage in the gall bladder. When open, the stored and concentrated bile exits into the duodenum
Duodenum
The duodenum is the first section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms anterior intestine or proximal intestine may be used instead of duodenum...
. This conduction of bile is the main function of the common bile duct. The hormone cholecystokinin
Cholecystokinin
Cholecystokinin is a peptide hormone of the gastrointestinal system responsible for stimulating the digestion of fat and protein...
, when stimulated by a fatty meal, promotes bile secretion by increased production of hepatic bile, contraction of the gall bladder, and relaxation of the Sphincter of Oddi.
Several problems can arise within the common bile duct. If clogged by a gallstone
Gallstone
A gallstone is a crystalline concretion formed within the gallbladder by accretion of bile components. These calculi are formed in the gallbladder, but may pass distally into other parts of the biliary tract such as the cystic duct, common bile duct, pancreatic duct, or the ampulla of...
, a condition called choledocholithiasis can result. In this clogged state, the duct is especially vulnerable to an infection called ascending cholangitis
Ascending cholangitis
Ascending cholangitis or acute cholangitis is an infection of the bile duct , usually caused by bacteria ascending from its junction with the duodenum...
. Very rare deformities of the common bile duct are cystic dilations (4 cm), choledochoceles (cystic dilation of the ampula of Vater (3–8 cm)), and biliary atresia
Biliary atresia
Biliary atresia, also known as "extrahepatic ductopenia" and "progressive obliterative cholangiopathy" is a congenital or acquired disease of the liver and one of the principle forms of chronic rejection of a transplanted liver allograft. As a birth defect in newborn infants, it has an occurrence...
.
Additional images
- S.E.Miederer et al.:Endoscopic transpapillary splitting of a choledochocele. Dtsch Med. Wochenschr. 1978 Feb.3:103(5):216,219. PMID 631041