A bile duct is any of a number of long tube-like structures that carry bile.

Bile, required for the digestion of food, is excreted by the liver into passages that carry bile toward the hepatic duct, which joins with the cystic duct (carrying bile to and from the gallbladder) to form the common bile duct, which opens into the intestine.

The biliary tree is the whole network of various sized ducts branching through the liver.

The path is as follows: Bile canaliculi → Canals of Hering → interlobular bile ducts → intrahepatic bile ducts → left and right hepatic ducts merge to form → common hepatic duct exits liver and joins → cystic duct (from gall bladder) forming → common bile duct → joins with pancreatic duct → forming ampulla of Vater → enters duodenum

Common bile duct

The top half of the common bile duct is associated with the liver, while the bottom half of the common bile duct is associated with the pancreas, through which it passes on its way to the intestine. It opens in the part of the intestine called the duodenum into a structure called the ampulla of Vater.

1: Right lobe of liver 2: Left lobe of liver 3: Quadrate lobe of liver 4: Round ligament of liver 5: Falciform ligament 6: Caudate lobe of liver 7: Inferior vena cava 8: Common bile duct 9: Hepatic artery 10: Portal vein 11: Cystic duct 12: Common hepatic duct 13: Gallbladder

The gall-bladder and bile ducts laid open.

Pathology

Blockage of the bile duct by a cancer, gallstones, or scarring from injury prevents the bile from being transported to the intestine and the active ingredient in the bile (bilirubin) instead accumulates in the blood. This condition results in jaundice, where the skin and eyes become yellow from the bilirubin in the blood. This condition also causes severe itchiness from the bilirubin deposited in the tissues. In certain types of jaundice, the urine will be noticeably darker, and the stools will be much paler than usual. This is caused by the bilirubin all going to the bloodstream and being filtered into the urine by the kidneys, instead of some being lost in the stools through the ampulla of Vater.

Jaundice is commonly caused by conditions such as pancreatic cancer, which causes blockage of the bile duct passing through the cancerous portion of the pancreas; cholangiocarcinoma, cancer of the bile ducts; blockage by a stone in patients with gallstones; and from scarring after injury to the bile duct during gallbladder removal.

Additional images

Section across portal canal of pig. X 250.

An intraoperative cholangiogram, which is an X-Ray of the bile ducts during a laprascopic cholecystectomy.

The common hepatic duct is the duct formed by the convergence of the right hepatic duct (which drains bile from the right functional lobe of the liver) and the left hepatic duct (which drains bile from the left functional lobe of the liver). The common hepatic duct then joins the cystic duct coming from the gallbladder to form the common bile duct. The duct is usually 6–8cm length and 6mm in diameter in adults.

The hepatic duct is part of the biliary tract that transports secretions from the liver into the intestines. It carries more volume in people who have had their gallbladder removed.

It is an important anatomic landmark during surgeries such as gall bladder removal. It forms one edge of Calot's triangle, along with the cystic duct and the cystic artery. All constituents of this triangle must be identified to avoid cutting or clipping the wrong structure.