Key organs of Biliary and Pancreatic Duct System:
- Liver produces bile
- Gallbladder stores and concentrates bile
- Pancreas produces pancreatic juices
- Duodenum receives bile and pancreatic juice, and mixes them with the contents of the GI tract
Key terms:
- Duct is a small tube.
- Ampulla is the dilated terminal end of the duct.
- Sphincter is a circular muscle.
- Papilla is a protuberance of target organ where the ampulla releases secretions.
Drainage Pathways:
- Right, left, and common hepatic ducts drain bile from the liver; their function is reflected in their name, as "hepatic" refers to the liver.
- Cystic duct carries bile to and from the gallbladder; it's helpful to know that "cystic" refers to the gallbladder (recall the "cystic" artery).
- Bile duct receives bile from the cystic and common hepatic ducts, and delivers it to the duodenum. Notice that its name simply reflects its contents (bile), not a specific organ.
- Main pancreatic duct drains pancreatic juice from pancreas
- Main pancreatic and common bile duct merge at hepatopancreatic ampulla (regulated by hepatopancreatic sphincter)
- Pancreatic juice and bile is drained into duodenum via major duodenal papilla.
- When present, accessory pancreatic duct drains pancreatic juice into duodenum via minor pancreatic papilla.
Embryologic Origins
Clinical correlations:
- Post-hepatic jaundice (aka, obstructive jaundice) refers to the yellow staining of body tissues, including skin and mucous membranes; it is the result of accumulation of yellow bile pigments in the blood, and is a sign that bile is not exiting the gallbladder appropriately.
- Gallstones, which are formed from crystalized bile, can become lodged within and obstruct the ducts of the biliary system, with serious health consequences.
For example:
- Cholecytitis (inflammation of the gallbladder) occurs when obstruction of the cycstic duct causes excessive bile accumulation in the gallbladder; subsequent swelling and irritation of the gallbladder can cause intense pain.
- Pancreatitis (aka, pancreatic inflammation) can result from obstruction of the hepatopancreatic ampulla; instead of entering the small intestine, bile and pancreatic juices back up into the pancreas, causing inflammation.
Duct/Artery associations:
- Cystic duct travels with the cystic artery
- Right and left hepatic ducts travel with the right and left hepatic arteries
- Common hepatic duct arises near the hepatic artery proper.