James A. Kashanian, M.D., is the Director of Male Sexual Health and Assistant Professor of Urology and Reproductive Medicine at Weill Cornell Medical College; and a Urologist at New York-Presbyterian Hospital, Cornell Campus.
Marc Goldstein, MD, DSc (hon), FACS is the Matthew P. Hardy Distinguished Professor of Reproductive Medicine, and Urology at Weill Cornell Medical College of Cornell University; Surgeon-in-Chief, Male Reproductive Medicine and Surgery; and Director of the Center for Male Reproductive Medicine and Microsurgery at the New York Presbyterian Hospital Weill Cornell Medical Center. He is Adjunct Senior Scientist with the Population Council’s Center for Biomedical Research, located on the campus of Rockefeller University.
Vasectomy is a simple and effective method for providing permanent contraception. Vasectomy is the surgical interruption of the two tubes (vas deferens) that carry a man's sperm from his testicles to his ejaculatory ducts, where the sperm are stored before departure from his body during orgasm. A vasectomy prevents sperm from being added to the man's ejaculation fluid (semen); therefore, he can no longer make a woman pregnant.
Emission is accomplished by contraction of the vas deferens, seminal vesicles, and ejaculatory ducts. This process is under adrenaline control. Ejection results from the rhythmic contractions of the muscles around the urethra, which causes the forcible ejection of the ejaculate. Within the spinal cord lies the ejaculation center which is the area involved in the coordination of signals from the brain and penis that eventually lead to ejaculation.
In normal men there exists a linear sexual response cycle: desire, arousal, plateau, orgasm, and resolution.
Abrupt bending of the erect penis can result in a tear in the tunica albuginea (the lining of the erectile bodies). This results in the instantaneous loss of the erection. In extreme cases, a tear in the urethra (urine channel) can also occur.
Penile fracture is considered a urologic emergency and when a penile fracture is suspected an urgent urologic consultation is needed. Failure to repair the tunica albuginea injury is associated with the development of delayed penile curvature and erectile dysfunction (ED).
Priapism is defined as a prolonged erection developing in the absence of sexual stimulation and unrelieved by ejaculation. The duration of the erection considered to represent priapism is generally over four hours.
What is Erectile Dysfunction?
Erectile dysfunction (ED) can be classified as organic, psychogenic or mixed. Organic ED is due to physical defects and can be further sub-classified. Psychogenic ED is secondary to psychological factors that are thought to inhibit a man's ability to achieve an erection because of specific stressors. ED often has a mixed component of both organic and psychogenic etiologies.
Peyronie's disease is a medical condition characterized by the development of a lump on the shaft of the penis. This lump is a scar (plaque) that forms on the lining (tunica albuginea) of the penile erectile body (corpus cavernosum). It is believed to be the result of direct injury to the penis. Early on following the trauma, an inflammatory reaction occurs, often bringing a man's attention to the problem because of pain associated with his erection. With time, the inflammation progresses and a scar develops.
Penile size differs between men of different ethnic backgrounds, and large studies of penis girth and length have been conducted by condom manufacturers. What many men perceive as a short penis actually falls into normal range size. Based on many published charts, scientific articles and self reported web based surveys, 95% of Caucasian men will fall into one of the following categories of size:
Dr. Schlegel is an internationally acclaimed expert in the treatment of male infertility, especially the interface of male factor treatment with assisted reproductive techniques. His work has also clarified the importance of hormonal therapy, sperm analysis and genetic studies in the evaluation of men with infertility. He was awarded the 1996 Established Clinician Award by The European Society for Human Reproduction and Embryology.