Gallengang

The Gallengang, or biliary duct system, is the network that transports bile from the liver and gallbladder to the duodenum. It forms part of the biliary tract and coordinates the flow of bile into the digestive tract.

Anatomy

Intrahepatic bile ducts collect bile within the liver and converge into the right and left hepatic ducts. These ducts join to form the common hepatic duct. The cystic duct from the gallbladder merges with the common hepatic duct to form the common bile duct (ductus choledochus), which passes toward the duodenum and releases bile via the major duodenal papilla with the sphincter of Oddi.

Function

Bile ducts transport bile, a fluid containing bile acids, bilirubin, cholesterol, and phospholipids, which emulsifies fats and aids digestion. Between meals, bile is stored and concentrated in the gallbladder and released in response to cholecystokinin during digestion.

Clinical relevance

Anatomical variants can complicate surgical procedures, particularly cholecystectomy. Obstruction of the bile ducts may occur due to stones (choledocholithiasis), tumors, or strictures, causing jaundice, dark urine, pale stools, and abdominal pain. Infections such as cholangitis can accompany obstruction and require urgent evaluation.

Diagnosis and treatment

Initial imaging often includes ultrasound; magnetic resonance cholangiopancreatography (MRCP) noninvasively visualizes the ducts. Endoscopic retrograde cholangiopancreatography (ERCP) permits both diagnosis and treatment, such as stone extraction or stent placement. Management of biliary obstruction may involve endoscopic or surgical interventions, including cholecystectomy when indicated.

Development

The biliary tree develops from the hepatic diverticulum in embryonic life, forming progressively the intrahepatic and extrahepatic bile ducts and the gallbladder.