What is the function of the gallbladder in the digestive system?
The gallbladder is a small, hollow, pouch-like organ that lies just under the right side of the liver (see the figure here). It is about 8 cm (3.1 in.) long and shaped like a tapered sac, with the open end continuous with the cystic duct. The gallbladder stores and concentrates bile from the liver until it is needed in the duodenum to help digest lipids. After the bile leaves the liver, it reaches the gallbladder through the cystic duct. At any given time, the gallbladder may store between 30 and 60 mL (1-2 oz) of bile. A hormone stimulated by the presence of fat in the duodenum signals the gallbladder to contract and force its contents back through the cystic duct and into the common bile duct to drain into the duodenum.