Inroduction

The urinary bladder can be compared to a big flexible muscular balloon that stores urine produced by the body from its kidneys. To fill and store urine, the bladder expands. When it wants to empty, it contracts, thereby pushing urine out. At the base of the bladder, a tube called the urethra is attached and is the path though which urine comes out. The urethra is surrounded at the base by a muscle valve mechanism called a urinary sphincter that stays closed to keep urine in and opens to let urine out. To fill, store and keep urine in the bladder, a coordination of closing the sphincter and relaxing The urinary bladder can be compared to a big flexible muscular balloon that stores urine produced by the body from its kidneys. To fill and store urine, the bladder expands. When it wants to empty, it contracts, thereby pushing urine out. At the base of the bladder, a tube called the urethra is attached and is the path though which urine comes out. The urethra is surrounded at the base by a muscle valve mechanism called a urinary sphincter that stays closed to keep urine in and opens to let urine out. To fill, store and keep urine in the bladder, a coordination of closing the phincter and relaxing