The constitution of the secretion of the vaginal mucous membrane, or of the secretion formed in the cervical canal, or both of these in combination, may constitute hindrances to the normal contact of spermatozoon and ovum.
The secretions of the female genital organs are manifold. The outer surface of the labia majora is covered with skin, containing sebaceous and sweat glands; but the inner surface of the labia majora and the rest of the external genital organs are covered with mucous membrane, the outer stratum of which consists of stratified pavement epithelium; this epithelium contains sebaceous glands and mucus glands. The intermixture of the secretions of these glands with the epithelial scales which are constantly being cast off in large numbers, constitutes the whitish material with which this region is smeared, known as “smegma.” A mucus secretion of a fluid consistency is discharged from the vulvo-vaginal glands known by the name of Bartholin’s glands.
The mucous lining of the vagina is poor in glands; it contains very numerous papillæ, which do not, however, project from the surface of the membrane, since the depressions between the papillæ are filled in by the stratified epithelium with which the entire extent of the vaginal mucous membrane is covered. The secretion of the vaginal mucous membrane is a fluid of thin consistency with an acid reaction; the admixture of numerous morphological elements, in the form of epithelial cells cast off from the superficial layers of the stratified epithelium, often, however, makes the vaginal secretion thick and opaque. The epithelial lamellae are frequently covered with heaps of lepthothrix granules, and among the granules are seen vibriones and bacteria and also numerous lepthothrix threads of varying length.
The same stratified epithelium extends on to the neck of the uterus to a distance which varies in different individuals; gradually, however, the number of layers diminishes, the flattened cells give place to thicker, prismatic cells, until we have a single-layered prismatic epithelium; finally the cells become columnar and ciliated, and this columnar ciliated epithelium covers the whole of the interior of the uterus. The mucous lining of the cervical canal contains numerous mucous glands, some of which are simple tubular glands, whilst others are racemose; they are lined with columnar ciliated epithelium, and secrete a dense, gelatinous, alkaline mucus, containing a few epithelial cells and occasional leucocytes. The mucous membrane of the uterine cavity is beset with simple tubular glands, lined with a single layer of prismatic epithelium; these glands secrete a grayish alkaline fluid. The secretion formed in the uterine cavity is thinner in consistency than that formed in the cervical canal.
Normally, the secretion of the vaginal mucous membrane is not more than is sufficient to keep the surface of the canal moist and slippery; it is a thin fluid of an acid reaction, and almost as clear as water. Shortly before and after menstruation, the secretion of the vaginal mucous membrane becomes more abundant; it is even thinner than at other times; the reaction remains acid. The secretion of the cervical canal is normally, in the absence of sexual intercourse, small in amount, so that a free flow of secretion from the os uteri externum is by itself sufficient to indicate that the mucous membrane of the canal is in an abnormal condition. The vitreous, gelatinous, alkaline mucus secreted by the glands of the cervical canal is normally retained within the canal, and is seen on examination with the speculum to fill the os uteri externum. In consequence of the congestion of the uterus that occurs during menstruation, and for the same reason during sexual excitement, the secretion of the cervical canal is more abundant, it also becomes less tenacious, and flows out through the os into the vagina. But this evacuation of the cervical secretion through the os is a normal occurrence only during menstruation and as a result of sexual intercourse; in these circumstances it appears in the form of a clear or somewhat yellowish drop of fluid exuding through the os uteri externum.
In catarrhal states, the secretions of the genital passage, like those of other mucous membranes, become abnormal. There is an increase in the number both of epithelial elements and of leucocytes; and in very acute catarrhs, erythrocytes also mingle with the secretion. On microscopical examination we find that the catarrhal secretion differs in its characters according to the part from which it is derived: the mucus from the cervical canal forms gelatinous accumulations; that from the vaginal mucous membrane forms thick opaque masses; and in the mixed secretion which exudes from the vulva, we find also smegma from the external genital organs. In addition to cells from the laminated epithelium, we see often young cells, somewhat oval or polyhedral in form, with granular protoplasm, and a vesicular nucleus. In some inflammatory states, pus corpuscles will also make their appearance. Various micro-organisms are in addition to be found in the catarrhal secretions.
The reaction of the vaginal secretion is normally faintly acid; should it become strongly acid, the movements of the spermatozoa are immediately suspended. The mucus of the cervical canal, the alkaline reaction of which is extremely favourable to the onward movement of the spermatozoa, may, owing to catarrhal processes, be so altered that it becomes acid; it then destroys the spermatozoa, and gives rise to sterility. This fact can sometimes be proved by microscopical examination. In several cases in which endometritis existed in sterile women I made a microscopical examination of the cervical mucus shortly after the completion of sexual intercourse; and in a number of these, no living spermatozoa were to be seen, but only dead, motionless spermatozoa (Fig. [82]). I had, of course, in these cases, previously assured myself that the husband’s semen was normally active.
Fig. [82].
Mucus from the Cervical Canal, taken one hour after sexual intercourse, from a woman suffering from chronic endometritis.
Among the epithelial cells, pus cells, and finely granular masses, we see a few motionless, dead spermatozoa.
According to Nöggerath, in cases of uterine catarrh, we may find one of three different varieties of secretion. In some cases it is small in amount, and very thin in consistency; in others, it is moderate in amount, very thick, non-transparent, bright yellow, and gelatinous in consistency; in the third class of cases, we have numerous degrees of variation, starting from the normal, purely mucus, transparent secretion, mixed with yellow flocculae, up to a secretion which has almost the aspect of pure pus. The first described variety is, according to Nöggerath, met with chiefly in women whose uteri are small, with indurated tissues, and its discharge seems to depend upon commencing atrophy of the mucous membrane. The second form is the most obstinate, the catarrh being situated chiefly in the cervical and probably also the uterine glands; whereas the first variety of secretion is rather a serous transudation, and contains very few formed elements. The third form is characterized by extensive denudation of the superficial epithelium, and is mixed with a smaller or larger quantity of pus.