Like man, most animals need a regular supply of nutriments. Eating and drinking cater for this need, but not with 100% efficiency. A considerable part of the conswned goods are expelled from the body as defecation. Waste products from the blood are filtered by the kidneys and excreted as urine. 1ms process continues throughout the day. In many situations, however, it would be very inconvenient to be expelling urine. Animals that leak urine continuously are more easily traced by preditors than the ones that don't. Besides this, for mankind it is socially intolerable at certain moments. Nature supplied q solution that enables storage of urine until a convenient moment for voiding: the bladder. Upon desire the bladder contracts and urine is expelled through the urethra, which, with the bladder, constitutes ti,e lower urinary tract. Thus the bladder owner controls when and where to expel urine.

Nierstichting Nederland, Stichting Urologisch Wetenschappelijk Onderzoek (SUWO, Rotterdam)
F.H. Schröder (Fritz) , R. van Mastrigt (Ron)
Erasmus University Rotterdam
Erasmus MC: University Medical Center Rotterdam

le Feber, J. (2000, October 4). Neurophysiological modeling of Voiding in Rats. Retrieved from