Organ
Common bile duct
Final extrahepatic route from the liver and gallbladder
High-yield
Trace four regions: above the duodenum, behind it, in the pancreatic region and within the duodenal wall. The final pancreatic-duct junction is variable.
Overview
Below the cystic duct junction, the extrahepatic bile passage is called the common bile duct. It descends beside the portal structures, passes behind the proximal duodenum and runs through or against the pancreatic head. It reaches the descending duodenum, commonly joining the main pancreatic duct before opening at the major papilla.
Reference facts
- Location
- Extends from the cystic–common hepatic duct junction to the medial wall of the descending duodenum.
- Parts
- Supraduodenal, retroduodenal, pancreatic and intramural duodenal portions.
- Blood supply
- Small hepatic/cystic and gastroduodenal/pancreaticoduodenal branches contribute to a longitudinal periductal vascular network.
- Innervation
- Hepatic and celiac autonomic pathways, with vagal parasympathetic fibers.
- Relations
- The portal vein is posterior in the hepatoduodenal ligament and hepatic artery is usually to the left; distally the duct is closely related to the pancreatic head.
- Function
- Carries bile into the duodenum; distal sphincter resistance and gallbladder contraction help determine bile flow through the extrahepatic ducts.
Clinical correlation
A stone within this duct or a lesion near its pancreatic segment can block bile flow and cause jaundice. Duct caliber must be interpreted with symptoms, imaging technique, age and prior gallbladder surgery rather than a universal numerical cutoff.
Frequently asked questions
Where is the common bile duct located?
The common bile duct lies extends from the cystic–common hepatic duct junction to the medial wall of the descending duodenum.
What does the common bile duct do?
Carries bile into the duodenum; distal sphincter resistance and gallbladder contraction help determine bile flow through the extrahepatic ducts.
What are the parts of the common bile duct?
The parts of the common bile duct are the supraduodenal, retroduodenal, pancreatic and intramural duodenal portions.
What is the blood supply of the common bile duct?
Small hepatic/cystic and gastroduodenal/pancreaticoduodenal branches contribute to a longitudinal periductal vascular network.