Читать книгу Saving Your Sex Life: A Guide for Men With Prostate Cancer - John P. Mulhall - Страница 11

Much in the same way that the multiple tissues of the penis act in concert to achieve erection, the aforementioned reproductive organs—prostate, seminal vesicles and vas deferens—function together to ensure normal ejaculation. During sexual activity, after a threshold amount of stimulation (this varies dramatically from person to person),ejaculation occurs.The ejaculatory process starts by increased nerve signals coming from the brain to the spinal cord. The ejaculation control center is at the junction of the thoracic and lumbar spinal cord. Nerves travel from the spinal cord and travel to the prostate, seminal vesicle and vas deferens. Interestingly, these nerves use adrenaline (the anti-erection chemical) as their major neurotransmitter for the purposes of ejaculation. The neurotransmitter in the brain that is most intimately involved in ejaculation is serotonin. During arousal, prior to ejaculation, the seminal vesicle and the vas deferens contract and deposit semen into the urethra as it runs through the prostate. At the same time, there is simultaneous closure of the bladder neck, which is the opening between the bladder and the urethra sitting above the prostate, and the urethral sphincter, which sits below the prostate. This causes a high-pressure zone inside the urethra within the prostate. This is followed by the sudden opening of the urethral sphincter combined with rhythmic contractions of the muscles around the urethra, which forces semen out through the urethra, resulting in ejaculation. In patients who have had radical prostatectomy surgery, of course, there is no ejaculatory apparatus to produce or deliver semen, and so they fail to ejaculate. Likewise as previously mentioned, radiation therapy can cause damage to the ejaculation ducts, such that these patients either have a significant reduction in the amount of ejaculate or have a complete absence of ejaculate. In patients after surgery or radiation, the muscles surrounding the urethra still contract at the time of orgasm, so the genital throbbing sensation that men experience at orgasm should remain.

In men who have a benign prostate disease (BPH), the enlarged prostate may, in fact, interfere with this ejaculatory process, and if they are using certain prostate medications for their prostate enlargement (medications known as alpha blockers, such as Flomax, Uroxatral, Hytrin, or Cardura) or if they’ve had surgery for the prostate, the bladder neck will not close properly and they will experience retrograde ejaculation. This is a condition where the semen, rather than traveling out through the urethra and ejaculate, passes back into the bladder and is then passed out in the first urination after orgasm. Patients who have this problem because of medications can stop the medication, and it is fully reversible.

However, patients who have had surgery for benign prostate enlargement (such as TURP, green light laser, microwave therapy) cannot generally be cured of this, as it is a structural problem. It is surprisingly common for patients not to be informed that after radical prostatectomy and after radiation therapy that there will be significant interference with their ejaculation. For the majority of older men, this is not a major concern, as they are not interested in fertility, and most older men do not assign any major significance to the production of semen. However, in younger men, the production of semen and the process of ejaculation may for some be significant contributors to sexual satisfaction, and the loss of this may impact upon the quality of their sexual lives. This is not a physical process,but more a psychological one. It is very common to produce a tiny amount of clear sticky fluid at urethral meatus (opening of the urethra). This should be of no concern, as this fluid (known as pre-cum) is fluid that is produced by glands inside the urethra which are not interfered with by surgery or radiation. Most importantly, this fluid contains no sperm.

Orgasm is, in the words of Captain James Kirk, the final frontier. Little is known about the physiology of orgasm in comparison to the physiology of erection or ejaculation. Orgasm is a brain event and it has been shown at the time of orgasm that men and women have brain activity that is as close to a seizure as possible without there being an actual seizure. The ability to achieve orgasm, as well as its intensity, is mediated by many different factors, predominantly psychological, but some physical. Most patients after radical prostatectomy and radiation therapy achieve an orgasm, although many will say that it is different, particularly after surgery. Indeed, interestingly, about 10% of them will say that their orgasm intensity is better after surgery than before. What is surprising to most people is that, even in the complete absence of any erection whatsoever, they are capable of achieving an orgasm, and this is routine. I will discuss problems with orgasm later on in Chapter 8.