Urethral Sensory Receptors in Voiding Physiology and Lower Urinary Tract Symptoms

Voiding is not a sole action of the bladder, but a complex interaction and integration of signals from the bladder, the outlet consisting of urethra and sphincter complex, and the central nervous system. The urethra appears to be more than a simple tube that transports urine; it serves as a sensory unit that is necessary for maintaining continence and micturition. Several reflexes originating in the urethra have an influence on bladder activity, possibly through an extensive sensory web with specialised cells. In normal conditions, urethral flow and/or distension for example enable bladder contraction to prolong until complete emptying. Although the exact mechanisms remain unknown, it is believed that urethral dysfunction may be an important contributor to the pathophysiology of lower urinary tract symptoms (LUTS). In this review, we aim to give a brief insight into the role of the proximal urethra in voiding physiology and LUTS, uncovering some of its secrets.