The gallbladder is a small organ that stores the bile that's produced by the liver. Bile aids in the digestion of fat and may crystallize into a solid form known as a gallstone.
Anatomy
The gallbladder is located under a concave area of the liver called the gallbladder fossa. The adult gallbladder is about 3.1 inches long and 1.5 inches in diameter when full.
Ducts
Bile flows through the hepatic duct from the liver and into the gallbladder through the cystic duct. During digestion, bile drains out the gallbladder through the cystic duct and into the common bile duct where it's eventually secreted into the duodenum.
Storage
Bile becomes much more concentrated while it's being stored in the gallbladder, which increases its effectiveness in digesting fats. The capacity of the adult gallbladder is about 1.7 ounces.
Gallstone Formation
Bile may become so concentrated that it forms a solid gallstone. Gallstones generally don't cause symptoms until they grow to at least 0.3 inches in diameter.
Gallstone Classification
A gallstone that's at least 80 percent cholesterol is classified as a cholesterol stone; gallstones with less than 20 percent cholesterol are classified as pigment stones. Gallstones with compositions between these two levels are considered to be mixed stones.
