Common hepatic duct in the context of Major duodenal papilla

In vertebrates, the gallbladder, also known as the cholecyst, is a small hollow organ where bile is stored and concentrated before it is released into the small intestine. In humans, the pear-shaped gallbladder lies beneath the liver, although the structure and position of the gallbladder can vary significantly among animal species. It receives bile, produced by the liver, via the common hepatic duct, and stores it. The bile is then released via the common bile duct into the duodenum, where the bile helps in the digestion of fats.

The gallbladder can be affected by gallstones, formed by material that cannot be dissolved – usually cholesterol or bilirubin, a product of hemoglobin breakdown. These may cause significant pain, particularly in the upper-right corner of the abdomen, and are often treated with removal of the gallbladder (called a cholecystectomy). Inflammation of the gallbladder (called cholecystitis) has a wide range of causes, including the result of gallstone impaction, infection, and autoimmune disease.

The pancreatic duct or duct of Wirsung (also, the major pancreatic duct due to the existence of an accessory pancreatic duct) is a duct joining the pancreas to the common bile duct. This supplies it with pancreatic juice from the exocrine pancreas, which aids in digestion.

The biliary tract (also biliary tree or biliary system) refers to the liver, gallbladder and bile ducts, and how they work together to make, store and secrete bile. Bile consists of water, electrolytes, bile acids, cholesterol, phospholipids and conjugated bilirubin. Some components are synthesized by hepatocytes (liver cells); the rest are extracted from the blood by the liver.

Bile is secreted by the liver into small ducts that join to form the common hepatic duct. Between meals, secreted bile is stored in the gallbladder. During a meal, the bile is secreted into the duodenum (part of the small intestine) to rid the body of waste stored in the bile as well as aid in the absorption of dietary fats and oils.

The common bile duct (also bile duct) is a part of the biliary tract. It is formed by the union of the common hepatic duct and cystic duct. It ends by uniting with the pancreatic duct to form the ampulla of Vater (hepatopancreatic ampulla). Its sphincter the sphincter of Oddi, enables the regulation of bile flow.