Functions of the ovary.—The ovary is lined by a layer of genital epithelia (“Keimepithel”), which undergo certain changes during the entire sexual life of the woman. The epithelia are continually transformed into ova. When a single genital epithelium leaves the ovarian lining to be transformed into an ovum it moves from the periphery toward the centre. It then surrounds itself with follicular epithelia and forms the Graafian follicle. Through its growth the Graafian follicle approaches again the periphery. All ripe Graafian follicles are, therefore, situated near the periphery of the ovary.
Ovulation.—About once a month a general congestion of the entire genital system takes place.F This congestion causes an effusion of serum and blood into the Graafian follicle and the rupture of the same. In this way the ovum is set free and is seized by the fimbriae of the Fallopian tube. The ovum begins now its journey towards the uterus. During its progress through the oviduct the maturition of the ovum, or the reduction of its chromosomes to half the number peculiar to its species, takes place by a double segmentation. The ovum is divided, twice in succession, each time into two quite unequal parts. The smaller segments, called polar bodies, remain near the periphery of the ovum and are extruded later on. The ovum is now ripe for fertilization.
According to Bischoff and Hiss, the impregnation takes place in the distal end of the tube. After impregnation the zygote continues its wandering by the current of the ciliated epithelia of the tube, towards the uterus. The ovum needs, according to Hensen, from three to five days, according to Bischoff eight days, to transverse this way, in the woman. It could not last any longer, says Von Winckel, because the uterine end of the tube, in the human female, has a diameter of only two to three millimeters, while the diameter of the ovum, in the second week of pregnancy, is three to six millimeters already. Hence, when a retardation, for one cause or another, takes place, a tubal pregnancy will be the result.
When the impregnated ovum has reached the cavity of the uterus it penetrates through the epithelium into the submucous fibrous tissues of the uterus, where it completes its development.
Internal ovarian secretion.—Besides the function of preparing the ova, the ovary has an internal secretion which is the cause of the female secondary characteristics. When both ovaries are removed before puberty, the time when the stamp of sex is becoming impressed on every part of the body, the essential feminine features fail to develop. The absence of the ovaries leads to the development of a colorless, neuter creature of angular form, strident voice, striding gait, and even of bearded chin.
Function of the Fallopian tubes.—The function of the ducts is to furnish a path for the ovum in its passage towards the uterus and for the spermatozoa on their way to meet the ovum. The current of the tubal ciliated epithelia is directed towards the uterus. In this way the ovum which does not possess self-motion, as do the spermatozoa, is carried towards its destination, while the spermatozoa have to swim against the current.
Menstruation.—The main function of the uterus is to serve as a couch or resting place for the fertilized ovum during its development. For this end a wound has to be set in the lining of the uterus to facilitate the grafting of the fertilized ovum, just as the gardner makes a slit for ingrafting the young shoot. The preparation of the ingrafting of the young animal is accomplished by the monthly changes in the uterus preceding menstruation. The monthly general congestion of the genital organs, necessary for the ovum to leave the Graafian follicle, also causes the uterine mucous membrane to swell from one to three millimeters in the thickness.G The mucosa becomes thus turgid and velvety. The epithelial cells of the endometrium swell and multiply. The openings of the uterine glands are enlarged, and a whitish, opaque mucus is poured out. The glandular cells are enlarged, and there is a multiplication of the round cells of the stroma. The cells are cloudy and filled with fat granules. This fatty degeneration involves the glandular cells, the cells of the inter-glandular tissue, and the cells of the blood vessels which are distended with blood. The endometrium or lining is thus prepared for the reception of the impregnated ovum. These alterations develop independently of the haemorrhage. The swelling begins a long time before the period and reaches its maximum only at this time.
If the ovum has become impregnated it is ready to respond to these preparations. If, however, nature’s attempt to reproduce an individual of the species has been frustrated, and the ovum has not been impregnated, the latter has to be cast out, and all the preparations are eliminated. The exuberant epithelial cells are exfoliated. The delicate capillaries, engorged with blood, sweat drops of blood by diapedesis or burst and discharge their contents. The congested and engorged glands secrete and excrete profusely.
This mingled mass of epithelial cells, blood and mucus leaves the body in form of menstrual discharges. Menstruation, therefore, is a retrograde process, in consequence of the failure of the impregnation of the ovum. The monthly flow is like the shedding of the leaves by the tree, the getting rid of some material the function of which has been frustrated and for which the economy has no more use.
Menstruation is thus the manifest phenomenon of the retrograde metamorphosis which ensues at the failure of the ovum to become fertilized. Where there is fertilization there is no menstruation. Hence, those women who marry immediately after menstruation sets in, at puberty,H and are impregnated and those women who are impregnated immediately after they finished nursing their babies, will seldom show the phenomenon of menstruation. This is the reason why menstruation is so rarely observed among animals.I
The concubitalis function of the uterus.—Another highly important function of the uterus is to serve as an organ of copulation. During the orgasm, at the moment of the highest excitement, the uterus descends deeper into the small pelvis.J It is assisted in the descent by the pressure of the abdominal muscles. The uterus, usually flattened in the sagittal direction, assumes a round, pear-shaped form during the orgasm and for some time afterwards. In this way a real cavum uteri is produced, and through the vacuum thus produced, the uterus is able to suck in the semen by means of aspiration. Furthermore, through the excitation, the circular fibres of the cervix contract at the same time as the longitudinal fibres. The result is a dilatation of the cervical orifice. The formerly flat opening becomes round. At the same time the uterine orifices of the tubes, which are generally closed, open widely and challenge the entrance of the spermatozoa.
Female ejaculation.—The contraction of the cervical fibres also causes the erection of the vaginal portion and of the neck of the uterus. This erection, at the moment of the highest orgasm, serves to expel Kristeller’s slimy plug from the cervix. This expulsion represents female ejaculation. After the expulsion the cervix becomes soft and flabby. The erection and sudden relaxation of the cervix cause the external os to open, sometimes to the extent of fully three centimeters, and to make several successive gasps. Each time the gasp draws powerfully the external os into the cervix and causes the aspiration of the semen.
Function of the vagina.—The function of the vagina is to serve as a receptacle of penis and semen. The erectile tissue which runs along the entire length between the different membranes, forming the vaginal wall, helps the vagina to adjust itself to the volume of the penis and to augment its turgescence. The muscular fibres, situated within the tunica media of the vaginal mucous membrane, contract during the ejaculation of the semen. The contraction is of a peristaltic nature, starting from the vaginal aperture. In this way the semen is stowed toward the uterine orifice under a certain pressure and is prevented from flowing off.
Previous to this contraction the sphincter cunni, the analogous muscle to the musculus bulbo-cavernosus in the male, also contracts and clinches the penis, pressing, at the same time, upon the two bulbs of the vestibule. In this way the vaginal orifice is more firmly compressed.
Function of the Bartholinian glands.—Through the activity of the constrictor cunni, the Bartholinian glands are also compressed. Normally these glands are inactive. They only secrete on irritation.K At the first voluptuary thrills, the lubricating fluid gushes forth from the Bartholinian glands, moistens the sexual organs, prepares the way for the painless entrance of the male organ and furnishes the ante-orgastic libido which is second only to the orgasm itself, and is the only libido experienced by many women throughout their lives.
The alkaline lubricating fluid from the Bartholinian glands serves the further purpose of neutralizing the vaginal contents which are of an acid reaction. But for the alkaline secretions, before the male ejaculation, the spermatozoa would be killed by the acids, or, at least, checked in their movements. The secretion of the Bartholinian glands has, therefore, a threefold purpose: it facilitates the frictions, neutralizes somewhat the vaginal contents, and increases or furnishes the ant-orgastic libido.
Function of the clitoris.—The most sensitive organ of the female genital apparatus is the clitoris. In the female child the clitoris, analogous to the penis in the male, represents the main erogenous zone, and its activity manifests itself by frequent twitchings and erections. After puberty the main function of the clitoris is, according to Freud, to transmit the stimuli to the other genital organs.
The erection of the clitoris is produced in the same way as the erection of the penis, by the relaxation of the arteries of the corpora cavernosa of the clitoris, which are thus filled with blood. The erection is further helped by the contraction of the muscles ischio-cavernosus and constrictor cunni. The clitoris has a direction, inverse to that of the erected penis, namely, downward. By virtue of its direction and its angle, the erected clitoris is able to yield and descend to meet the dorsal face of the glans and body of the penis, without being in a position to rise again during its action. The contraction of the two last named muscles will, therefore, help to press the right-angled clitoris on the dorsal side of the penis. The erection and the bending of the clitoris are further helped by the action of the bulbs of the vestibule which, through the pressure of the penis, send their fluid to the corpora cavernosa and the glans of the clitoris and thus increase the sensitiveness.
Ordo rei.—According to the functions of the different organs, the initus muliebris takes the following course. As soon as the mentula reaches the vestibule, the glans of the clitoris is pressed down to the vaginal edge of the orifice of the vagina to meet the glans fascini. Under the influence of the erotic irritation, the tonus of the blood vessels of the corpora cavernosa clitoridis and of the bulbs is removed, and the organs fill with blood. The erected clitoris, bent down and pressing upon the dorsal surface fascini, is thus unable to rise again.
At the first touch of these sensitive organs, the lubricating fluid gushes forth from the Bartholinian glands, moistens the vaginal orifice, and prepares the way for the painless entrance fascini. The glans fascini passes now the two edges of the vaginal bulbs, et collum corpusque fascini are seized by the protruding parts of these bulbs. The constrictor cunni now clinches the vaginal orifice, and the vagina, by means of its erectile tissue, adjusts itself to the volume mentulæ. At the moment of the male ejaculation a peristaltic contraction of the vagina takes place, by which the sperma is stowed toward the uterus and is prevented from flowing off until the female ejaculation has taken place.
In the meantime the uterus descends deeper into the small pelvis, and its muscles open the three uterine orifices. The secretions of the cervical glands, or Kristeller’s plug, are now expressed through the open external os, and a suction of small amounts of sperma into the cervical canal ensues. The expression of the cervical secretions represents the female ejaculation and takes place at the moment of the highest orgasm.