genitourinary disorders
Overview of Male Sexual Function and Dysfunction
Ejaculation and Orgasm
Ejaculationis controlled by the sympathetic nervous system. Neural stimulation of the alpha-adrenergic receptors in the male adnexa (eg, penis, testes, perineum, prostate, seminal vesicles) causes contractions of the epididymis, vas deferens, seminal vesicles, and prostate that transport semen to the posterior urethra. Then, rhythmic contractions of the pelvic floor muscles result in pulsatile ejaculation of the accumulated seminal fluid. At the same time, the neck of the bladder closes, preventing retrograde ejaculation of semen into the bladder. Selective serotonin reuptake inhibitors and alpha blockers may delay or inhibit ejaculation by receptor inhibition at these sites. Orgasmis the pleasurable sensation that occurs in the brain generally simultaneously with ejaculation. Anorgasmia may be a physical phenomenon due to decreased penile sensation (eg, from neuropathy) or a neuropsychologic phenomenon due to psychiatric disorders or psychoactive drugs. Ejaculatory dysfunction is reduced or absent semen volume. It may result from retrograde ejaculation, which may occur in men with diabetes or as a complication of bladder neck surgery or transurethral resection of the prostate. It also may result from sympathetic interruption, either due to surgery (eg, retroperitoneal lymph node dissection) or to drugs (eg, guanethidine,phentolamine,phenoxybenzamine,thioridazine). Radical prostatectomy (removal of the prostate gland plus the seminal vesicles and regional lymph nodes) eliminates any ejaculation because removing the seminal vesicles and prostate eliminates semen production. Premature ejaculation is defined as ejaculation occurring sooner than desired by the man or his partner and causing distress to the couple. It is usually caused by sexual inexperience, anxiety, and other psychologic factors instead of disease. It can be treated successfully with topical anesthetics, sex therapy, tricyclic antidepressants, and selective serotonin reuptake inhibitors. 