<P> The gallbladder can be affected by gallstones, formed by material that cannot be dissolved--usually cholesterol or bilirubin, a product of haemoglobin breakdown . These may cause significant pain, particularly in the right upper corner of the abdomen, and are often treated with removal of the gallbladder called a cholecystectomy . Cholecystitis, inflammation of the gallbladder, has a wide range of causes, including result from the impaction of gallstones, infection, and autoimmune disease . </P> <P> The gallbladder is a hollow organ that sits in a shallow depression below the right lobe of the liver, that is grey - blue in life . In adults, the gallbladder measures approximately 7 to 10 centimetres (2.8 to 3.9 inches) in length and 4 centimetres (1.6 in) in diameter when fully distended . The gallbladder has a capacity of about 50 millilitres (1.8 imperial fluid ounces). </P> <P> The gallbladder is shaped like a pear, with its tip opening into the cystic duct . The gallbladder is divided into three sections: the fundus, body, and neck . The fundus is the rounded base, angled so that it faces the abdominal wall . The body lies in a depression in the surface of the lower liver . The neck tapers and is continuous with the cystic duct, part of the biliary tree . The gallbladder fossa, against which the fundus and body of the gallbladder lie, is found beneath the junction of hepatic segments IVB and V . The cystic duct unites with the common hepatic duct to become the common bile duct . At the junction of the neck of the gallbladder and the cystic duct, there is an out - pouching of the gallbladder wall forming a mucosal fold known as "Hartmann's pouch". </P> <P> The gallbladder wall is composed of a number of layers . The gallbladder wall's innermost surface is lined by a single layer of columnar cells with a brush border of microvilli, very similar to intestinal absorptive cells . Underneath the epithelium is an underlying lamina propria, a muscular layer, an outer perimuscular layer and serosa . Unlike elsewhere in the intestinal tract, the gallbladder does not have a muscularis mucosae, and the muscular fibres are not arranged in distinct layers . </P>

Where is the fundus of the gallbladder located