Urinary bladder an organ that regularly stores a hyperosmotic concentration of urine. It therefore is relatively impermeable and has multiple epithelial layers. The urinary bladder of the cetaceans (whales and dolphins) is proportionally smaller than that of land-dwelling mammals. In the whole class of Aves there is no urinary bladder per se. Although all birds have kidneys, the ureters open directly into a cloaca which serves as a reservoir for urine, fecal matter, and eggs. In crustaceans, the urinary bladder consists of two sets of lateral and central lobes. Urinary bladder The urinary bladder is a hollow muscular organ in humans and
Underactive bladder et al. (2014). "Pathophysiology and animal modeling of underactive bladder." Int Urol Nephrol 46 Suppl 1: 11-21. van Koeveringe, G. A., K. L. Rademakers, et al. (2014). "Detrusor underactivity: Pathophysiological considerations, models and proposals for future research. ICI-RS 2013." Neurourol Urodyn 33(5): 591-596. Underactive bladder Underactive bladder syndrome (UAB) describes symptoms of difficulty with bladder emptying, such as hesitancy to start the stream, a poor or intermittent stream, or sensations of incomplete bladder emptying. The physical finding of detrusor pressurization of insufficient strength or duration to ensure timely and efficient bladder emptying is properly termed "detrusor underactivity" (DU) (Abrams et