bile duct

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Any of the excretory passages in the liver that carry bile to the hepatic duct, which joins with the cystic duct to form the common bile duct opening into the duodenum.

The passages in the liver and gallbladder that move bile into the duodenum.

1. generally, any of the biliary passages.
2. specifically the terminal segment of the biliary tree extending from the union of the common hepatic duct and cystic duct to the major duodenal papilla. See also bile passages.

• b. d. atresia — if it is extensive it causes jaundice and steatorrhea soon after birth. It is observed rarely in kittens and puppies.
• b. d. calculi — see cholelithiasis.
• b. d. canaliculi — formed between adjacent hepatocytes these are the smallest components of the biliary system; they open into biliary ductules.
• b. d. carcinoma — see cholangiocellular carcinoma.
• b. d. cysts — occur in all species and are probably derived from occluded or atretic embryonic bile ducts.
• b. d. ductule — bile duct.
• b. d. dyskinesia — a much-argued diagnosis in human medicine. The diagnosis assumes that there is a failure of biliary flow into the intestine for other than physical reasons. The hypothesis likens the problem to that of irritable colon. There is no proof of the existence of the malfunction in humans, much less in animals.
• b. d. fibrosis — a common severe lesion, accompanied by mineralization, as a result of infestation by Fasciola hepatica.
• b. d. hyperplasia — may be part of a general reaction of the liver but is most important as a purely cholangiolar proliferation, usually as a result of exposure to a poison such as butter yellow.
• b. d. inflammation — see cholangiohepatitis.
• b. d. obstruction — see biliary obstruction.
• b. d. proliferation — see bile duct hyperplasia (above).
• b. d. radiology — see cholangiography.
• b. d. rupture/perforation — most ruptures are traumatic and result in leakage of bile into the peritoneal cavity. See also biliary peritonitis.
• b. d. tumors — see cholangiocellular.

Bile duct
Digestive system diagram showing the bile duct
An intraoperative cholangiogram, which is an X-Ray of the bile ducts during a laprascopic cholecystectomy

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 (see below) 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

Contents 1 Common bile duct 2 Pathology 3 Additional images 4 External links

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.

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 is called jaundice and 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.

External links

• The Cholangiocarcinoma Foundation
• The Johns Hopkins Gall Bladder & Bile Duct Cancer Web page
• bile+duct at eMedicine Dictionary
• MeSH Bile+Ducts

v • d • e Anatomy of torso, digestive system: accessory digestive glands Liver by region: Left lobe (Caudate lobe, Quadrate lobe) • Right lobe • Transverse fissure of liver • Bare area of the liver by function: Fibrous capsule of Glisson • Hepatocyte • Space of Disse • Space of Mall • Kupffer cell • Liver sinusoid • Hepatic stellate cell • Hepatic lobule Biliary tract Bile ducts intrahepatic: Bile canaliculus • Canals of Hering • Interlobular bile ducts • Intrahepatic bile ducts • Left and Right hepatic ducts extrahepatic: Common hepatic duct • Cystic duct • Common bile duct Gallbladder by region: Body • Fundus • Neck Pancreas by region: Tail • Body • Neck • Head • Uncinate process by function: Islets of Langerhans • Exocrine pancreas ducts: Pancreatic duct • Accessory pancreatic duct Common Hepatopancreatic ampulla • Sphincter of Oddi

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