gallbladder

gallbladder

[gawl-blad-er]

Muscular membranous sac under the liver that stores and concentrates bile. Pear-shaped and expandable, it holds about 1.7 fluid oz (50 ml). Its inner surface absorbs water and inorganic salts from bile, which becomes 5–18 times more concentrated than when it leaves the liver. The gallbladder contracts to discharge bile through the bile duct into the duodenum. Disorders include gallstones and inflammation (cholecystitis). Surgical removal of the gallbladder (cholecystectomy) has no serious side effects.

Learn more about gallbladder with a free trial on Britannica.com.

The gallbladder (or cholecyst, sometimes gall bladder) is a small organ whose function in the body is to store bile and aid in the digestive process.

Anatomy

The cystic duct connects the gall bladder to the common hepatic duct to form the common bile duct. This common bile duct then joins the pancreatic duct, and enters through the hepatopancreatic ampulla at the major duodenal papilla.

The fundus of the gallbladder is the part farthest from the duct, located by the lower border of the liver . It is at the same level as the transpyloric plane.

Microscopic anatomy

The different layers of the gallbladder are as follows:

Section References

Function

The gallbladder stores about 50 mL (1.7 US fluid ounces / 1.8 Imperial fluid ounces) of bile, which is released when food containing fat enters the digestive tract, stimulating the secretion of cholecystokinin (CCK). The bile, produced in the liver, emulsifies fats and neutralizes acids in partly digested food.

After being stored in the gallbladder the bile becomes more concentrated than when it left the liver, increasing its potency and intensifying its effect on fats. Most digestion occurs in the duodenum.

Vertebrates have gallbladders, but invertebrates don't. This is because vertebrates eat in boluses while invertebrates are constantly eating. To digest a large bolus of food requires a large amount of digestive secretions, hence the presence of a gallbladder.

Diseases and disorders

See also

References

Search another word or see gallbladderon Dictionary | Thesaurus |Spanish
Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature