PERIPHERAL DISTRIBUTION OF THE HUMAN DORSAL NERVE OF THE PENIS

Purpose: The integrity of the dorsal nerve of the penis is crucial for normal erectile and ejaculatory function. To our knowledge a descript ion of this nerve along the phallus has not been formally described. W e illustrate the distribution of the dorsal nerve of the penis to the penile shaft, anterior urethra and glans. Materials and Methods: Neuro anatomical dissections were performed on 28 cadaver penis specimens. E lectrodiagnostic testing was conducted on 10 healthy male subjects to confirm the anatomical findings. Results: The dorsal nerve of the peni s consists of 2 populations of axons, one to innervate the penile shaf t and urethra, and the other to innervate the glans. Stimulation of th e urethra resulted in responses recorded in the main trunk of the dors al nerve of the penis and stimulation of the nerve evoked responses wi thin the urethra. Bulbocavernosus muscle contraction was elicited foll owing urethral stimulation. Conclusions: Urethral innervation by the d orsal nerve of the penis supports the view that urethral afferent impu lses are a component of reflex ejaculatory activity. The pattern of gl anular innervation by the dorsal nerve of the penis identifies the gla ns as a sensory end organ for sexual reflexes. The undulating characte r of the dorsal nerve of the penis is a mechanism by which the nerve c an accommodate to significant changes in penile length with erection. Electrodiagnostic studies of the dorsal nerve of the penis should be m odified to consider the anatomical findings.