The gonads are the glands responsible for the essentials of reproduction. They also produce the characteristic sex hormones of either sex, although other centers can make sex hormones in lesser quantities. In the male this is represented by the testes and in the female by the ovaries.
Gonad derived from the Greek word gone, meaning seed. So, you might say, generally, it’s involved with the “seed” or reproductive processes of the body. Now does it make sense? Of course. It simply intrigues me how these names are created, but when they are related back to their origin, they so often make a lot of good sense. This occurs with most medical terms. The majority have been derived from either Greek or Latin words, and when you check in a medical dictionary—a favorite pastime of mine—the link is usually instantly obvious, as with “gone.”
Gonads organs of reproduction and the manufacture of the sex hormones in adult life. This all kicks off at “puberty,” when the organs are suddenly stirred into unprecedented activity. But in infancy and childhood they simply lie dormant, waiting for Mother Nature to come knocking at the door in a few years time, which she invariably does in a very capable manner!
The female’s gonadal system is represented by the ovaries. Later in life these will produce the egg each menstrual month, and also female hormones called estrogen and progesterone. These will have a profound effect on her reproductive system, the ova, uterus and tubes and breasts.
Male’s gonad organs are the two testes. One is located in each side of the scrotum that hangs like a little bag between the legs. When he starts showing the so-called secondary sexual characteristics, these will suddenly spurt to life.
The testicles will produce two elements: first, testosterone, the male sex hormone. This is responsible for many things, including libido, sexual sensations plus the secondary sexual characteristics that are so obvious during the teen years. Second, the testes will also produce the spermatozoa, the male cells of reproduction.
Fortunately not, for they are quiescent. However, there are a few considerations I feel are worth mentioning at this time, for they may be important and even life-endangering.
During the later part of prenatal life or very soon after birth, the testes descend from the back wall of the abdomen through an aperture in the front wall of the abdomen, to descend via the inguinal canals to reach the scrotum, the skin covered pouch where they remain thereafter. They are two in number, of firm consistency, and measuring about 4 cm by 2.5 cm.
Each testis has two distinct parts, the somniferous tubules and the so-called interstitial or Leydig cells. The somniferous tubules consist of lobules that produce spermatozoa after becoming fully developed at puberty. This takes place under the action of the hormone testosterone, aided by estrogenic hormone.
It is essential that the temperature of the testes be lower than the rest of the body, for the cells are very sensitive to heat; sperm production may be retarded by overheating. This is the reason why the testes are located outside the body, where the surroundings are cooler.
If the testes are not in the scrotum by the time the follicle-stimulating hormone (FSH) starts to act on them at puberty (causing their development), they may be permanently impaired. This is one reason why any abnormally placed testis must be brought down to its rightful location during the prepubertal years.
Another is the very high risk of malignancy (cancer) developing in a testis that remains in the abdominal cavity at this time. The interstitial cells of the testis produce the male hormone testosterone. It is a very potent hormone (a so-called androgen). Prenatally, testosterone is responsible for the development of the male genital tract, and during and after puberty it is essential for continual spermatogenesis (sperm formation).
However, testosterone also plays a profound part in the development of the secondary sexual characteristics of the male. These include growth and development of the sexual organs (penis, prostate and scrotum); skeletal and muscular growth; growth and distribution of hair on the face, under the arms and in the pubic area; the breaking of the voice and laryngeal development.
Gonadotrophins are the hormones produced by the anterior lobe of the pituitary gland, and consist of FSH, necessary for sperm formation, and luteinizing hormone (LH), which works on the interstitial cells and aids testosterone production.
Taking male sex hormones orally (as some do in the hope it may increase their libido) tends to depress the plasma levels of LH but has little effect on FSH levels unless very large doses are taken.
Therefore, the chances of its affecting libido favorably are slight for it merely dampens down the naturally occurring reasons for this. (For further details on these hormones see Chapter 2 of this section, where the pituitary gland and its functions are described in detail.) Several tests that measure testicular function are available, and these are sometimes used to check disorders.
Spermatogenic function is checked by directly examining seminal fluid. Normally not less than 20 million sperms per ml arc present, although pregnancy may occur with lesser counts provided sperm motility is particularly marked. Androgenic (hormonal) function can be assessed only after puberty. If the secondary sexual characteristics have occurred, it indicates that secretion is normal.
Gonadotrophic hormone can be measured either in the blood or urine. Testicular biopsy may sometimes be necessary if there is doubt as to the activity of the scrotal components.
Apart from undescended testes (cryptorchids), pathological irregularities are rare. However, they often receive considerable lay press coverage due to the incredible focus of public interest on all matters relating to sex these days.