Reflex mechanisms for bladder inhibition.

Continence of urine requires ability of the bladder to maintain a low intravesical pressure at increasing filling, in order to preserve a positive urethral-bladder pressure gradient. During micturition the conditions are reversed: the bladder has to generate pressures exceeding the urethral pressure, which also presupposes that the urethra opens and remains open as long as is required for all urine to be expelled. These events are made possible by a complicated pattern of central and peripheral neural responses, affecting the bladder-urethral unit. The pioneer work of determining the reflex mechanisms involved in the regulation of the lower urinary tract was done at the beginning of this century. Recently, further studies have been made and by means of electrophysiological investigations previous data have been confirmed. In this communication some important observations are reviewed and one example is given of how bladder inhibitory reflexes are utilized in therapy.