Dangerous age in men - the prostate gland

The prostate gland is both a urinary and a sexual organ. It is also thought to have an in ternal secretion which aids the functional activity of the body. About the size of a horse-chestnut, it is situated at the neck of the bladder and is penetrated by the urethra. Irregular in form, the prostate is flattened from before backward, with its base upward where it blends with the muscles at the neck of the bladder. In this way it helps control the urine. The long axis of the prostate is vertical when the body is in a vertical position, and is about 1^4 inches long. Its transverse diameter, greatest near the base, measures about i 1 /* inches, and its antero-posterior diameter measures (about) I inch. Its usual weight is from 20 to 25 grams, nearly the same as that of the testis.

The prostate and testicles, rudimentary in early life, increase rapidly in size toward puberty. At this time, as in the other genital organs, active evolution occurs, and from then on the structural and functional development of the one is inti mately associated with that of the other. This con tinues up to the age of forty-five or fifty. It may then again increase in size, becoming double or triple its normal volume. This process is called hypertrophy. In some cases a reverse process oc curs. The gland shrinks and becomes smaller. Atrophy is the term then applied, and frequently it is as troublesome as the hypertrophic condition. These will be discussed in a later chapter.

The prostate consists of two lateral lobes and a medium portion composed of muscular and glandular tissue. The muscular element represents about one-half of the entire mass. Part of the muscle fibers embrace the floor of the prostatic urethra, forming a ring of great firmness and strength around the fifteen or twenty openings of the prostatic ducts. These tubes carry the fluid from the secreting structure of the prostate, the prostatic glands, grape-like clusters which termi nate in fine ducts leading into the tubes. The muscles about these tubes serve a double function; to prevent leakage of the prostatic fluid, and to intercept the backward flow of the semen and prostatic fluid during sexual congress. Muscular fibers intermingled with the glandular tissue initi ate the forward propulsion of the mingled pros tatic and seminal secretions, the ejaculation being further aided by the contraction of the surround ing muscles.

Two ejaculatory ducts pass through the sub stance of the prostate and empty upon the summit of the veru montanum, a small but important structure which forms part of the floor of the prostatic urethra. The fluid coming through these ducts from the seminal vesicles is mixed with the prostatic fluid at the time of ejaculation. It is here that the prostatic secretion serves to dilute the seminal fluid and to stimulate the spermatozoa to active movement.

The prostate gland is provided with a free blood supply as well as an extraordinary wealth of nerve fibers and nerve end organs. It is conceivable that the unusually rich blood and nerve supply may de termine, on the one hand, the readiness with which the gland undergoes congestive changes, and on the other hand, the numerous local and general nervous manifestations associated with prostatic inflammation.

The prostate gland is essentially generative. It also serves to reinforce the bladder neck, although its imperfect development in the female, in chil dren, and in eunuchs, appears to entail no defect in the muscular control. It is represented in the female by some poorly developed glands which open into the terminal portion of the urethra.

The urethra is the canal which conveys the urine from the bladder through the penis to the surface. It is lined with mucous membrane and conveys the seminal ejaculations during inter course or whenever emissions occur. In its course it pierces the prostate gland from base to apex. For descriptive purposes it is divided into three portions, the prostatic, the membranous and the spongy. Its course is somewhat S-shaped. Hyper trophy of the prostate may greatly lengthen the canal by stretching its internal end upward. Im bedded in the sphincter of the urethra ar^ two Cowper's glands. These produce an alkaline, glairy secretion, which probably acts to neutralize any acidity which might inhibit the activity of the spermatozoa.

The testes, two in number, are suspended in the scrotum from the groin, or inguinal region, by the spermatic cords. The left testicle hangs somewhat lower than the right in the majority of cases. Each gland consists of two portions, the testis proper and the epididymis. In each testis are from five to seven hundred little tubes, or tubules. The sper matozoa after being developed in these tubules are transmitted through the epididymis to the vas deferens. Thence, at orgasm, they reach the ure thra through the ejaculatory duct. This duct is formed by the junction of the vas deferens and a narrow duct coming from the corresponding semi nal vesicle.

The seminal vesicles are two hollow organs lying above the base of the prostate between the bladder and the rectum. They are two inches long and one-half inch in diameter, lie transversely along the upper border of the prostate, and in cline upwards, especially at the outer end. They are bound to the bladder wall by a layer of tissue or fascia, continued upwards from the back of the prostate. Each seminal vesicle consists of a coiled and folded tube which will stretch to about six inches in length. At the inner and lower end is the narrow duct which unites with the corresponding vas deferens to form the ejaculatory duct. The function of the seminal vesicle is to store sper matic fluid, to which it adds a secretion of its own.

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