Penile erectile tissue is contained in three corporal bodies: two dorsal corpora cavernosa and a single corpus spongiosum. All the corpora surrounded by a thick fibrous sheath, the tunica Albuginea. All the corpora contain numerous cavernous spaces separated by trabeculae, composed by trabeculae, composed of thick bundles of smooth muscles Corpus spongium contains fewer muscles cells. The walls of cavernous spaces are covered by endothelial cells resembling those found in the blood vessels. Sexual activity, initiated by parasympathetic stimulation via hypogastric nerve, promotes the release of Nitric oxide (NO) from the endothelium of corpora. NO activates enzyme guanylate cyclase, allowing production of cyclicGuanesine monophosphate (cGMP) which causes relaxation of smooth muscles. As arterioles and the muscles relax, lacunar spaces are filled with blood, increasing the pressure on the veins and occluding the venous return and causing the penis to become erect. If there is no further sexual stimulation, cGMP is metabolized by phosphodiesterase 5 (PDE5) resulting loss of erection.

After ejaculation sympathetic tonic discharge resumes adrenergic never terminals activate adrenergic receptors, resulting in contraction of smooth muscles around the sinusoids and arterioles. Much of the blood from the sinusoidal spaces is expelled and the venous channels reopen.

: For further Information contact Wnho Clinic, 2014 sadashiv peth, Tilak road, Pune. And Testimonials on Youtube Vidios- Dr. Ramesh Maheshwari, Pune.