Bladder
From LoveToKnow 1911
BLADDER (from A.S. blaeddre, connected with blawan, to blow, cf. Ger. blase), the membranous sac in animals which receives the urine secreted from the kidneys. The word is also used for any similar sac, such as the gall-bladder, the swimbladder in fishes, or the small vesicle in various seaweeds.

