The mere mention of impotence is enough to make some men cringe. Unfortunately, for millions of men in the United States, impotence is not a feared possibility but a demoralizing reality. Kevin L. Billups, MD I mpotence, or erectile dysfunction, is the persistent inability to achieve or maintain an erection sufficient for satisfactory sexual performance. All contribute to poor penile blood flow.
Penile erection is primarily a vascular event.
This is probably the first event leading to an erection. Central to the process of erection is relaxation of the smooth muscle in the corporal bodies. Smooth-muscle relaxation is triggered by a reduction in intracellular calcium. As the corporal bodies relax and fill with blood, the penis begins to become tumescent. Penile firmness and rigidity depend on adequate smooth-muscle relaxation.