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Simple or Sophisticated? The Male Reproductive System... Explained
At first glance, the male reproductive system may seem a good bit simpler than the female system, in terms of the intricacy of its “machinery” and general function. But while men don’t release an egg every month or suffer from the grueling symptoms of PMS (or have the ability to carry a fetus, but who’s counting?), their reproductive systems are actually quite complex. Like the female system, men's sexual and reproductive systems are also governed by hormones released by the brain, various genes, and complex physiological mechanisms that underlie the whole setup. And let’s face it: the ability to develop and maintain an erection is truly a feat of physics that should be appreciated by all.
For most men the system is pretty robust, especially while they are young, and that is perhaps why many tend to overlook the delicate biological balance behind it. The complexity of the system becomes particularly apparent when problems arise. Some common male reproductive issues include premature ejaculation and erectile dysfunction (ED) – both are examples of disorders that can occur from time to time in the normal man, under normal circumstances. This article will outline how the male reproductive system functions overall, including its anatomy and physiology under normal conditions. It will also discuss some of the problems that many men may experience from time to time (like premature ejaculation and impotence) and some of the issues associated with the aging process and declining testosterone levels (is there such a thing as male “menopause”?).
The Sperm-Making Machinery
Similar to the female system, the male reproductive system is governed by the brain’s hypothalamus, a region that is responsible for basic physiological processes like sleep, hunger, and sex drive. And just as for females, the hypothalamus releases the hormone GnRH, which exerts its effects on the pituitary gland, sitting just adjacent to the hypothalamus. In response to GnRH, the pituitary releases the sex hormones luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which make their way to the testicles and affect sperm production.
Cells in the testes called Leydig cells are responsible for making testosterone, and get their cue from LH to do this. Interestingly, cholesterol is the precursor of testosterone, meaning that it’s the building block from which testosterone is made, although there are several intermediate steps before testosterone itself is produced. (Unfortunately – or fortunately – this does not imply that men with high cholesterol will also have high levels of testosterone.) The hormone FSH signals the other main cell type of the testes, Sertoli cells, to begin producing sperm, in a process called spermatogenesis. The entire process of creating new sperm cells takes between 72 and 74 days to complete.(1) Each day a typical man produces about 100 million new sperm cells, though this number may decline with age. When they are mature, the sperm cells begin their migration out of the testes by way of the epididymis and vas deferens, a process that takes about two weeks to complete.(1) But before the sperm cells are ready to leave the body during ejaculation, they must pick up some additional fluids: these fluids come from the seminal vesicles, bulbourethral gland, and prostate, and together constitute semen.
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