SECT. VIII.
Of the Urinary Organs and Genital Parts.
The kidnies, the ureters, the bladder, and the urethra, are the principal urinary organs. The kidnies receive two arteries called the emulgent arteries, from the great arterial trunk, called aorta, before described; they each send also two veins back again, accompanying the arteries to the vena cava. Whilst the blood is circulated in the kidnies, the urine is secreted in many small quantities, and carried from each kidney by a tendinous tube, the bigness generally of a small goose quill, called the ureter to the bladder. The ureters enter the bladder between its lamillas, so as not to admit of a return. Hence, a bladder in its natural position is both wind and water tight, and if reversed, is neither.
The bladder of urine is of a tendinous and nervous texture, and capable of great extension, but at the same time exquisitely sensible. The neck of the bladder is very muscular, and by this forms a sphincter, or annular muscle, by which the urine is retained; and as it is of a very sensible nature, this part is subject to inflammatory constrictions; great pain, and many evils have there been occasioned, either from venereal cases, or gravelous complaints.
From the neck of the bladder to the end of the penis, is the urethra; which canal serves for the emission of the urine, as well as that of the seed.
The whole is lined with a number of very little glans, to lubricate and protect the sensitive lining from the sharpness of the urine.
These are the urinary organs. We will in the next place, proceed to the organs of generation.
The testicles are the principal instruments for forming the human seed; they are generally two in number. The testicles receive the blood, of which they secrete the seed, from the aorta, about the same parts, whence the emulgent arteries project. These arteries run down from the aorta to the testicles, in a very contorted and winding manner, accompanied by the veins which return back again from the testicles, and fix themselves in the ascending vena cava. These contorted and interwoven vessels are called the spermatic vessels, which carry the blood from the arteries in little quantities, and slowly return it again into the great vein.
Whilst the blood is circulated in the testicles, the seed is secreted in them; but as it is secreted, it is transported back again from thence by tubes, called vasa deferentia, towards the neck of the bladder, where there are two irregular bladder-like vessels, wherein the seed is contained, and kept for use, called the vesiculæ seminales.
In these seed bladders the seed is kept for use, till it is wanted. They are remarkably delicate and nervous; and when they are filled with seed, they stimulate all the organs of generation with a desire for venery.
The penis, or the manly member of generation, is partly covered with the common skin; the foremost part of which, that covers the glans, is called the præpuce. This præpuce is tied underneath to the substance of the penis, by what is called the frænum.
The inner part of the penis is composed of two kinds of bodies, the cavernous bodies of the penis, and the cavernous body of the urethra. The first are bodies enveloped in their peculiar teguments, and make the greatest part of the penis. Each of these bodies takes its origin from the erecting muscle of the penis, which is near the pubis; through each of them goes an artery and a nerve, which spread themselves through these bodies.
These bodies are full of cavities, which have all a communication with one another. The cavernous body of the urethra continues from the bulb, near the neck of the bladder all along to the end of the penis, and includes the glans, or the nut of the yard; and is much of the same substance with the former. At the back of the penis, goes along the large vein, called the vena penis, which spreads itself all along into numberless branches that connect themselves with the ramifications of the arteries throughout all the cavernous bodies; and from thence is caused the erection, as I shall presently describe. The glans, or the nut of the yard, is remarkably delicate and sensible, as being the seat of pleasure in coition; it is also of a cellular substance, and in one continuation with the cavernous body of the urethra.
Its sensation is greatly heightened by the frænum being tied underneath, from the præpuce to that part which keeps it, as it were, in an agreeable constriction when erect.
The penis is allowed two pair, and a single muscle. The first pair is the erectores, which take their origin from the fleshy protuberances of the ischium, and lose themselves in the cavernous body of the penis. The second pair of muscles is the transversales; these take their rise near the forementioned, and fasten themselves at the root of the penis. The fifth is the accelerator, or the odd muscle; this muscle takes its commencement from the cavernous body of the urethra, and grasps the whole penis, and adheres to the sphincter of the anus; the muscles aid and assist each other in the erection of the penis, which happens in the following manner:
At the influx of the animal spirits, the vena penis, or the great vein in the penis is somewhat contracted, whence the blood is forced into the cavernous bodies of the penis and that of the urethra, as the reflux of the circulating blood from the arteries is hindered; hence, the cellulæ of the cavernous bodies are obliged to swell up and distend all the parts, and thus make the penis turgid and erect; when the penis is further titillated by the friction of coition, the parts become generally irritated to an agreeable constriction, whereby the seed rushes from the seed-bladders into the urethra, and is thus forcibly ejected in the time of ejaculation; then the whole fabric slackens, the constriction of the great vein relaxes, the blood regains its free circulation, and the penis becomes slack again.
These are the faint out-lines of the genital parts; but to have a full description and comprehension of the peculiar properties of the genitals of both sexes, and also the sacred act of generation, I recommend to a serious perusal of the anatomical and physiological description of the genital parts of both sexes, in my Treatise on the Venereal Disease, where they will find a full and satisfactory account.