ETYM Old Eng. bladder, bleddre, AS. blaedre, blaeddre; akin to Icel. blathra, SW. bläddra, Dan. blaere, Dutch blaar, Old High Germ. blâtara the bladder in the body of animals, German blatter blister, bustule. Related to Blow, to puff.
Hollow elastic-walled organ which stores the urine produced in the kidneys. It is present in the urinary systems of some fishes, most amphibians, some reptiles, and all mammals. Urine enters the bladder through two ureters, one leading from each kidney, and leaves it through the urethra.
1. A bag that fills with air.
2. A distensible membranous sac (usually containing liquid or gas); SYN. vesica.