Physiology, Gallbladder

The gallbladder is a small hollow organ about the size and shape of a pear. It is a part of the biliary system, also known as the biliary tree or biliary tract. The biliary system is a series of ducts within the liver, gallbladder, and pancreas that empty into the small intestine. There are intrahepatic (within the liver) and extrahepatic (outside of the liver) components. The gallbladder is a component of the extrahepatic biliary system where bile is stored and concentrated. Bile is a fluid formed in the liver that is essential for digesting fats, excreting cholesterol, and even possesses antimicrobial activity. The gallbladder lies in the right upper quadrant of the abdomen affixed to the undersurface of the liver at the gallbladder fossa. It is attached to the rest of the extrahepatic biliary system via the cystic duct. The liver produces bile that is drained into the gallbladder and stored until needed for digestion.