bladder, urinary definition of bladder, urinary in the Free Online Encyclopedia.

bladder, urinary, muscular sac located in the pelvis that stores urine urine, clear, amber-colored fluid formed by the kidneys that carries metabolic wastes out of the body (see urinary system ). As the blood circulates it collects excretory products from the tissues and these substances are separated from the blood by the kidneys and
..... Click the link for more information. and contracts to expel it from the body. Urine enters the bladder from the kidneys through the ureters ureter (y
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..... Click the link for more information. . The bladder of the adult human can hold over a pint (0.6 liters) of urine. When the level of urine reaches about half this amount, pressure of the accumulating fluid stimulates nervous impulses that relax the external sphincter, a muscle that forms a dense band around the urethra at the base of the bladder. This muscle can be controlled voluntarily in most mammals. The muscles in the wall of the bladder also contract, forcing urine out through the urethra. The bladder is subject to infection (commonly called cystitis Interstitial cystitis is an inflammation of the bladder wall of unknown cause. It has the same symptoms as cystitis plus severe pelvic pain and frequency of urination (sometimes more than 60 times daily) that interferes with sleep, work, and daily life.
..... Click the link for more information. ) and the formation of stones. Its normal function may also be affected by nervous disorders or by external pressure, as from prostatic enlargement or pregnancy. See urinary system urinary system, group of organs of the body concerned with excretion of urine, that is, water and the waste products of metabolism. In humans, the kidneys are two small organs situated near the vertebral column at the small of the back, the left lying somewhat higher
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