Corpus luteum at the end of the ninth
month. From Dr. Montgomery.
“If an examination be made within the first three or four months after conception, we shall, I believe, always find the cavity still existing, and of such a size as to be capable of containing a grain of wheat at least, and very often of much greater dimensions: this cavity is surrounded by a strong white cyst (the inner coat of the Graafian vesicle,) and as gestation proceeds the opposite parts of this approximate, and at length close together, by which the cavity is completely obliterated, and in its place there remains an irregular white line, whose form is best expressed by calling it radiated or stelliform.”[5] Dr. Montgomery adds, “I am unable to state exactly at what period the central cavity disappears, or closes up to form the stellated line. I think I have invariably found it existing up to the end of the fourth month. I have one specimen in which it was closed in the fifth month, and another in which it was open in the sixth: later than this I never found it.”
When pregnancy is over, the corpus luteum gradually diminishes and disappears. Dr. Montgomery states that “the exact period of its total disappearance I am unable to state, but I have found it distinctly visible so late as at the end of five months after delivery at the full time, but not beyond this period.” Hence it will be seen that in a few months after the termination of pregnancy, all traces of the corpus luteum are lost, and that, therefore, it will be impossible to decide as to how frequently impregnation has taken place, merely by examining the ovaries, as has been supposed. There is also another point to which Dr. Montgomery has alluded, which is well worthy of notice: in mentioning the fact that a vesicle may contain two ova, and thus a woman be delivered of twins, and yet there be but one corpus luteum, he observes that “the presence of a corpus luteum does not prove that a woman has borne a child, although it would be a decided proof that she has been impregnated, and had conceived, because it is quite obvious that the ovum, after its vivification, may be, from a great variety of causes, blighted and destroyed, long before the fœtus has acquired any distinct form. It may have been converted into a mole or hydatids: thus, however paradoxical it may at first sight appear, it is nevertheless obviously true, that a woman may conceive and yet not become truly with child, a fact already alluded to, as noticed by Harvey; but the converse will not hold good. I believe no one ever found a fœtus in utero without a corpus luteum in the ovary; and that the truth of Haller’s carollary, ‘nullus unquam conceptus est absque corpore luteo’ remains undisputed.”
During childhood, the ovaries present a perfectly smooth surface, and their structure appears to be homogeneous, consisting of a dense cellular tissue. About the seventh year, the first traces of the Graafian vesicles make their appearance; as the period of puberty approaches, the whole gland enlarges, becomes softer and more vascular; the Graafian vesicles are more numerous, and generally one or two will be found larger and more prominent than the rest. After repeated impregnations, and especially towards that time of life when the catamenia are about to disappear, the ovary becomes more or less flabby and corrugated, and at a still more advanced age presents a shrivelled appearance.
The ovaries are liable to inflammation and its consequences, more especially abscess, general enlargement, and induration: the malignant changes of structure, viz. cephaloma, hæmatoma, and cancer, rarely have their origin in the ovaries, but extend to these organs from the adjacent parts. Lipomatous or fatty tumours are occasionally met with, containing hair, rudiments of teeth, &c. Cysts not unfrequently occur in the ovaries, and attain a very considerable size; they are simple or compound, sometimes consisting of several cysts one within the other, and distended with fluids, which vary considerably in their character. These tumours come under the general head of Ovarian Dropsy. The ovaries are also liable to many remarkable morbid changes in the puerperal state, such as softening and complete disorganization, the natural structure of the organ being entirely broken down and converted into a bloody pulpy mass; in some cases the whole gland is apparently dissolved away, so as scarcely to leave a trace of its previous existence.
Fallopian tubes. The Fallopian tubes, which act as excretory ducts to the ovaries, take their course through the upper portion of the broad ligaments, running from without inwards, towards the superior margin of the uterus, the ovaries being situated behind and somewhat above them. They are somewhat contorted, and are considerably more dilated at their abdominal extremity where they are unattached, than where they are connected to the uterus, being as much as from three to four lines at the former point; whereas, at the latter, they are not more than half a line.
Their abdominal extremity, which is like the mouth of a funnel, has its edge strongly fimbriated, and has hence been called the morsus diaboli. Their other extremity opens into the cavity of the uterus at the angle which the fundus forms with its sides, and the whole of the tube is about five inches.
The Fallopian tubes receive their external covering from the peritoneum, which becomes connected at their open extremity with the membrane which lines them. Between the external and internal membrane is the proper tissue of the tubes, and which, except in very muscular subjects, seldom display the fibrous structure; still, nevertheless, two layers of fibres have been observed—an outer or longitudinal, and an inner or circular layer. The Fallopian tubes are lined with mucous membrane, forming numerous longitudinal rugæ. The canal is not pervious during the early months of fœtal life, the abdominal extremity being closed and rounded; this appears to open about the fourth month. The canal is relatively larger, the younger the embryo is, and may, therefore, be easily demonstrated at this time.
At the period of impregnation, the Fallopian tubes implant themselves by means of their fimbriated extremity upon that part of the ovary where the Graafian vesicle is about to burst; they become remarkably engorged with blood, assuming a deep purple colour, and are now much thicker; the canal enlarges, so that a tolerably-sized probe can be introduced, whereas, at other periods it will scarcely admit a large bristle. The uterine extremity of the tube is closed by a continuation of that pulpy coagulable lymph-like secretion which now lines the cavity of the uterus, forming the membrana decidua of Hunter, and which, especially on the side where the corpus luteum is found, extends into the tube to nearly the distance of an inch. The tubes are now observed to be in a state of distinct peristaltic motion, “like writhing worms,” as Mr. Cruickshank has well expressed it; “the fimbriæ were also black and embraced the ovaria (like fingers laying hold of an object) so closely and so firmly, as to require some force and even slight laceration to disengage them.”[6] From the great degree of vascularity which is observed in the Fallopian tubes at this period, some anatomists have been induced to consider that their proper tissue was vascular, analogous to the corpora cavernosa penis. Besides the peristaltic motion already mentioned, other movements called ciliary have been observed in the Fallopian tubes at this period, consisting of minute portions of mucous membrane moving briskly and whirling round their axis, apparently for the purpose of propelling the ovum.[7]