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)…

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…

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…

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…