What is the effect of increased parasympathetic tone on erection?

What is the effect of increased parasympathetic tone on erection?

• A. Parasympathetics stimulate erection (correct)
• B. Parasympathetics inhibit erection
• C. No effect on erection
• D. Sympathetics stimulate erection

Answer: (A)

Erection is driven by parasympathetic activity that releases nitric oxide in the penile tissue. Increased parasympathetic tone activates pelvic nerves, and nitric oxide stimulates guanylate cyclase in smooth muscle, raising cGMP and causing relaxation of cavernous smooth muscle. This relaxation allows blood to flow into and trap within the corpora cavernosa, producing an erection. Sympathetic activity, by contrast, tends toward detumescence and ejaculation, not erection. So increasing parasympathetic tone directly promotes erection, making the correct statement that parasympathetics stimulate erection.

Erection is driven by parasympathetic activity that releases nitric oxide in the penile tissue. Increased parasympathetic tone activates pelvic nerves, and nitric oxide stimulates guanylate cyclase in smooth muscle, raising cGMP and causing relaxation of cavernous smooth muscle. This relaxation allows blood to flow into and trap within the corpora cavernosa, producing an erection. Sympathetic activity, by contrast, tends toward detumescence and ejaculation, not erection. So increasing parasympathetic tone directly promotes erection, making the correct statement that parasympathetics stimulate erection.