PENILE PHYSIOLOGY AND ERECTILE DYSFUNCTION: A REVIEW OF LITERATURE

Abstract

The penis is composed by one corpus spongiosum and two corpora cavernosa and is surrounded by the tunica albuginea with sensory and motor innervation. Parasympathetic innervation is primarily responsible for the erection and sympathetic nerves are responsible for ejaculation and the detumescence. Erection is a reflex neurovascular event in which sexual stimulation leads to release of nitric oxide, activating the NO-cGMP pathway and causing vascular relaxation and engorgement of the corpora cavernosa. The increase in penile blood flow culminates with an erection. Several factors such as cardiovascular disease and iatrogenic complications can lead to the development of erectile dysfunction, which brings psychological problems and self-confidence. Erectile dysfunction (ED) is defined as the inability of the man in attaining and maintaining penis erection sufficiently to permit satisfactory sexual intercourse. It is estimated that by 2025 about 300 million men will suffer from this problem. Various therapies have been used for the treatment of this disease such as psychotherapy and pharmacological treatment. In this respect, we highlight the use of phosphodiesterase inhibitors, which are the gold-standard in the treatment of erectile dysfunction as monotherapy. However, the different therapies have not been effective in all patients, requiring further investigation of new therapies. DESCRIPTORS: Penile Erection. Nitric Oxide. Erectile Dysfunction.