bladder

n. bag in an animal’s body. which serves asthe receptacle of the urine and can be blown up as afloat（动物的）膀胱，尿泡。
△H.VIII.3.2.360 (359):“Like little wanton boys that swim on bladders，”像那些抱着猪尿泡游水的调皮小男孩。

bladder囊

解剖学中指任何盛液体的空器官，尤指膀胱。膀胱位于盆腔内，膀胱底有左右输尿管入口；颈部有出口，通尿道。尿液存于膀胱内；充盈后排出。