Biliary Ducts

The biliary ducts are a series of pipe-like conduits which carry the hepatic bile from the liver and the gall bladder into the duodenum. There are five such conduits: the left and right hepatic ducts; the common hepatic duct; the cystic duct; and  the common bile duct. All biliary ducts are embedded in the hepatoduodenal ligament, which is a double-layer portion of the peritoneum called lesser omentum.

The left and right hepatic ducts arise from the left and right lobe of liver respectively as they are formed by the union of the bile ductules. They convey the bile synthesized and secreted by the liver cells (hepatocytes) into the common hepatic duct, which is formed by the union of the two aforementioned ducts. Then the common hepatic duct joins the cystic duct, which is 3 cm long, to form the common bile duct.

The common bile duct, which measures 7 cm in length, discharges the bile stored in the gall bladder into the duodenum. Before reaching this portion of the small intestine, the common bile duct meets the pancreatic duct to form the hepatopancreatic ampulla, through which both the bile and the pancreas digestive enzymes flow into the duodenum. They are all part of the hepatic bile system.

You must remember that the bile is an alkaline fluid secreted by hepatocytes. It contains bilirubins, bile salts, cholesterol, and steroids. It is involved in emulsification and absorption of the fat that enters the duodenum.

Above, schematic image showing all five biliary ducts and the gallbladder.