Neurophysiology of Erection and Ejaculation

Authors

  • François Giuliano MD, PhD

    Corresponding author
    1. Neuro-Uro-Andrology, Department of Physical Medicine and Rehabilitation, Raymond Poincaré Academic Hospital, Garches, Versailles Saint Quentin en Yvelines University, Garches, France
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François Giuliano, MD, PhD, Neuro-Uro-Andrology, Department of Physical Medicine and Rehabilitation, 104 bvd, Raymond Poincaré Academic Hospital, Garches, Versailles Saint Quentin en Yvelines University, Garches 92380, France. Tel: 33 147 107748; Fax: 33 147 104443; E-mail: giuliano@cyber-sante.org

ABSTRACT

Introduction.  Penile erection and ejaculation are closely associated during sexual intercourse. Erection is a central psychoneuroendocrine and peripheral neuro-vasculo-tissular event, resulting in blood filling the sinusoidal spaces of the corpora cavernosa and corpus spongiosum. Ejaculation represents the climax of the sexual cycle and comprises emission (secretion of semen) and expulsion (propulsion of semen) phases.

Aim.  This article provides an overview of the proposed neurophysiology of erection and ejaculation.

Methods.  Review of the literature.

Main Outcome Measures.  Current data on the neurophysiology of erection and ejaculation.

Results.  In terms of peripheral innervation, the pelvic plexus represents a junction for efferent nerves to the structures involved in erection and ejaculation. At the spinal level, the spinal cord contains three sets of neurons (thoracolumbar sympathetic, sacral parasympathetic, and somatic) innervating the sexual organs involved in erection and ejaculation. The presence of cerebral descending pathways to spinal erection and ejaculation centers indicates that the brain has an excitatory or inhibitory effect on these processes. Brain structures that modulate spinal command of erection and ejaculation are part of a larger network that is dedicated to regulating sexual responses. Neurophysiological and pharmacological research has elucidated that dopamine and serotonin have central roles in modulating erection and ejaculation. Interestingly, erection is not a prerequisite for ejaculation, and each of these sexual responses can exist without the other.

Conclusion.  Despite the association between erection and ejaculation during intercourse, these two processes can be considered distinct events from an anatomical, physiological, and pharmacological perspective. Giuliano F. Neurophysiology of erection and ejaculation. J Sex Med 2011;8(suppl 4):310–315.

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