Male Sexual Dysfunction

Physiology of Penile Erection

Innervation of the Penis

The autonomic spinal erection center is located in the intermediolateral nuclei of the spinal cord at levels S₂-S₄ and T₁₂-L₂. Nerve fibers from the thoracolumbar (sympathetic) and sacral (parasympathetic) spinal segments join…    

Signal Transduction in Penile Erection

During sexual stimulation, NO released from nerve ending and endothelium diffuses into the trabecular and arterial smooth-muscle cells to activate guanylyl cyclase, which catalyzes the formation of second messenger cyclic guanosine monophosphate (cGMP) (_{Trigo-Rocha et al, 1993}). cGMP…    

Hormones & Sexual Function

Androgens are essential for male sexual maturity. Testosterone regulates gonadotropin secretion and muscle development; dihydrotestosterone mediates all other aspects of male sexual maturation, including hair growth, acne, male pattern baldness, and spermatogenesis. In adults, androgen deficiency results in…    

Male Sexual Dysfunction Introduction

by Tom F. Lue, MD

A better understanding of male sexual dysfunction has been made possible by innovative laboratory and clinical research in the mechanism, neurophysiology, and pharmacology of penile erection. Erectile function can now…