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.
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Malignant tumour of the bladder. The most significant risk factor associated with bladder cancer is smoking. Exposure to chemicals called arylamines, which are used in the leather, rubber, printing, and textiles industries, is another risk factor. Most bladder cancers are diagnosed after the age of 60; men are affected more than women. Symptoms include blood in the urine, difficulty urinating, excessive urination, or, more rarely, painful urination. Bladder cancer can be treated with surgery, radiation therapy, or chemotherapy.
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