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 description of this nerve along the phallus has not been formally described. We illustrate the distribution of the dorsal nerve of the penis to the penile shaft, anterior urethra and glans.
MATERIALS AND METHODS: Neuroanatomical dissections were performed on 28 cadaver penis specimens. Electrodiagnostic testing was conducted on 10 healthy male subjects to confirm the anatomical findings.
RESULTS: The dorsal nerve of the penis consists of 2 populations of axons, one to innervate the penile shaft and urethra, and the other to innervate the glans. Stimulation of the urethra resulted in responses recorded in the main trunk of the dorsal nerve of the penis and stimulation of the nerve evoked responses within the urethra. Bulbocavernosus muscle contraction was elicited following urethral stimulation.
CONCLUSIONS: Urethral innervation by the dorsal nerve of the penis supports the view that urethral afferent impulses are a component of reflex ejaculatory activity. The pattern of glanular innervation by the dorsal nerve of the penis identifies the glans as a sensory end organ for sexual reflexes. The undulating character of the dorsal nerve of the penis is a mechanism by which the nerve can accommodate to significant changes in penile length with erection. Electrodiagnostic studies of the dorsal nerve of the penis should be modified to consider the anatomical findings.