Love: A Treatise on the Science of Sex-attraction / for the use of Physicians and Students of Medical Jurisprudence

by Bernard Simon Talmey

Colliculus.—With the erection of the corpora cavernosa, the colliculus also swells and almost fills up the entire lumen of the prostatic urethra. In this way the bladder which has already been closed by the contraction of the sphincter, is closed up more tightly, so that not a drop of urine could escape. The erection of the colliculus also causes the orifices of the ejaculatory ducts to take the direction forwards toward the pars membranacea.

Urethra.—At this stage the urethra obtains an actual lumen. Through the net of veins which surround the mucous membrane of the urethra and through the turgescence of the corpus cavernosum urethrae, the canal of the urethra opens and remains gaping through the entire duration of the erection. In this way it is admirably fitted to give a free passage for the semen. In the mean time the urethral glands are constantly secreting their viscid clear fluid, which, together with the secretion of the Cowper’s glands, provide a lubricating and protecting coat for the urethra and neutralize the contents of the urethral walls which are otherwise bathed in acid urine.

Ejaculation.—The last important step of the male sexual act is ejaculation. The spermatozoa leave the lining of the tubuli contorti and wander through the tubuli recti to the rete vasculosum and hence through the vasa efferentia to the head of the epididymis. They continue their wanderings through the epididymis and vasa deferentia until they reach the seminal vesicles and the ejaculatory ducts. During sexual tranquility and in a normal state of health, the ejaculatory ducts, owing to the narrowness of their diameter and the oblique direction of their orifices, are sufficiently compressed to prevent the semen from reaching the urethra. The semen, therefore, remains in the seminal vesicles until needed for ejaculation. If not needed in due time, it is, as a rule, reabsorbed, and the overflow, if there be any, is discharged during sleep, accompanied by libidinous dreams.

Coincident with erection the entire situation changes. Before ejaculation the testicles are forcibly drawn up to the external rings of the inguinal canal, by the action of the cremaster muscle. Through the contraction of the epididymis and the coni vasculosi, the seminal fluid is propelled toward the vasa deferentia. Through the peristaltic movement of the vasa deferentia and the seminal vesicles, the semen is pressed into the ejaculatory ducts. The latter, by means of the muscular layer in their walls, forward the semen to the prostatic urethra. The action of the ducts is at this moment facilitated by the changed direction of their orifices. The change takes place through the turgescence of the colliculus. The swelling of the colliculus and the contraction of the external sphincter of the bladder prevent the semen from flowing backward into the bladder.

At this stage the muscular substance of the prostate contracts and squeezes out the prostatic fluid into the urethra. The fluid had been stowed up in the follicles until there was a demand for it. All these secretions of the testicles, seminal vesicles, and prostate, meet synchronously in the prostatic urethra and are there temporarily stowed up.

The muscular layer which surrounds the membranous portion of the urethra is a veritable sphincter, the contractions or dilatations of which will propel or retain the semen. The semen pouring from the ejaculatory ducts and the secretion of the prostate are steadily forced forward. But, retained by the contracted sphincter externus, the semen is forced into the bulb of the urethra, as the place of least resistance. In this way the bulbous part of the urethra becomes distended and serves as a temporary reservoir for the semen before ejaculation. By reflex excitation, this distention causes spasmodic contractions of the musculus bulbo-cavernosus and clonic contractions of the accelerator urinae. The contractions of these two muscles overcome the contractions of the sphincter, i. e., the muscular layer of the membranous portion of the urethra, and the semen is driven forward and gushes out of the meatus, in several jets, through the open and well-lubricated canal of the urethra.

Nervous control of erection.—The mechanism of erection and ejaculation is controlled by six centres, the three cerebral, one in the medulla oblongata, and the two spinal. Erection may be caused by the stimulation of the cerebral centre of voluptas. Impressions originating in the brain, as sexual thoughts, may evoke vigorous erections. There is no function of the human economy over which the mind exerts a more powerful influence than over that of sex. The imagination, says Hammond, is always a more potent stimulant of sexual desires than the physiological incentive supplied by nature. Besides by imagination, the cerebral centre may be excited by impressions conveyed through the senses. Sight, smell, hearing, and in some pathological states even taste are well known to convey sexual stimulation to the brain. The sense of touch has such an influence over the generative function that it is considered the inseparable companion of sexual activity.

CUT XXXIII.

Diagram of nerves and centres.[D]
1, brain; 2, centre of inhibition; 3, centre of libido; 11, centre of voluptas; 4, vasodilatory centre in the medulla oblongata; 16, centre of erection; 7, centre of ejaculation; 10, genitals at the periphery. The broken lines designate centripetal nerves, the solid lines denote centrifugal nerves.