View source for Paper - The development of the prostate gland in the human female and homologies of the urethra and vagina of the sexes

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| [[File:Mark_Hill.jpg|90px|left]] This historic 1911 paper by Evatt is an early description of female genital "prostate" development. Regnier de Graaf (1641–1673) first described the female prostate in 1672 and this anatomical structure, even today, remains a controversial matter.

See also - {{Ref-Spaulding1921}}
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'''Modern Notes:''' [[Vagina Development]] | [[Genital System Development]] | [[Fetal Development]]
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<pubmed>28258707</pubmed>

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{{Historic Disclaimer}}
=A Contribution to the Development of the Prostate Gland in the Human Female, and a Study of the Homologies of the Urethra and Vagina of the Sexes=

by Evelyn John Evatt, 

Professor of Anatomy, Manitoba Medical College, Winnipeg.


==Introduction==
IN the human male a fusiform ﬁbro-muscular structure, supporting glandular tissue, is found in relation to the whole length of that part of the urethra which extends from the outlet of the bladder to the deep layer of the triangular ligament: this gland is known as the prostate.


FIG. 1. Bl,, bladder; U., urethra; W., Wolﬁian duct; Utr.,utriculus prostaticus; . R., rectum ; Ut , uterus; V., vagina; H., hymen.

That an organ homologous with this exists in some part of the female urogenital system cannot be doubted; but, owing to the uncertainty of our knowledge regarding the homologies of these organs, it is diﬂicult to know where in the female to look for a structure corresponding to the prostate. In the male we recognise a part of the prostate in relation to the urogenital canal, that is, in relation to that part of the urethra which lies between the attachment of the genital cord and the deep layer of the triangular ligament, and also a part in relation to the urethra between the genital cord and the Vesical outlet (ﬁg. 1, A).


The usual method of accounting for the development of the female urethra, and bringing it into line with the male, is summed up in Cunningham’s Text-book of Antomy as follows :—

“The female urethra is developed from that part of the anterior portion of the cloaca which lies below the developing bladder, and above the openings of the Miillerian and Wolflian ducts. The part below these openings, the urogenital canal, during the course of development, becomes shorter and shorter, and ﬁnally forms the epithelium at the bottom of the urogenital cleft, immediately surrounding the urethral and vaginal openings. Thus, in the adult the urethra, which originally led into the urogenital canal, opens into the urogenital ﬁssure; the lower fused portions of the Miillerian ducts, which in the embryo occupy the genital cord, represent the sinus poeularis of the male.

FIG. 2. Bl., bladder; U.,urethra; W., Wolﬁian duct; Utr., utricnlusprostaticus; R., rectum; Ut., uterus; V., vagina; H., hymen; U.C., urogenital canal.



“The vaginal portion of the fused Miilslerian ducts is at first relatively Very short, and at the point where it opens into the urogenital canal a slight fold appears, which is the future hymen. The vagina increases rapidly in length, and its opening moves downwards towards the urogenital cleft.

“In the foetus the Wolﬂian ducts can be traced along each side of the uterus as far as the upper end of the vagina.

“Striped muscular ﬁbres are also found in connection with the female urethra, and are especially plentiful in the lower part of the anterior wall of the passage.”


If this be the correct history of the development of the female urethra and vagina, we should expect to ﬁnd traces of the prostate in relation to the anterior and posterior walls of the vagina. Fig. 2 represents an attempt to visualise the development of the vagina on the lines suggested above. I have failed to ﬁnd any prostatic remnants in relation to the posterior vaginal wall, and I have not read of them having been observed in this position.

Quoting from Gray’s Anatomy :—

“Berry Hart has described the Wolfﬁan ducts as ending at the site of the future hymen in bulbous enlargements, which he has named the Wolfﬁan bulbs, and states that the hymen is formed from these bulbs. He also regards the colliculus seminalis of the male urethra as being formed from the lower part of the Wolfﬁan ducts.

“Ultimately the Miillerian ducts open into the urogenital sinus between the oriﬁces of the Wolfliari ducts, and terminate in an elevation named the Miillerian eminence. Berry Hart describes them as ending blindly on this eminence.

“In the female the Miillerian ducts persist and undergo development, The portions which lie in the genital cord fuse to form the uterus and the vagina; the fusion of the Miillerian ducts begins in the third month, and the septum formed by their fused mesial walls disappears from below upwards, and thus the cavities of the uterus and vagina are formed.” Diagrammatically, his view of the relative position_of the prostate in the female would also be represented by ﬁg. 2, C.

The development of the vagina in the manner just described would necessitate the growth of a septum between it and the urethra; but Wood- Jones maintains that no such septum exists, and that “ the vagina is, for a great part of foetal life, a solid and not an open canal at all.” He says further, “Early in the history of the embryo the Mullerian ducts open into the urogenital sinus at its upper part; late in its history they open at the hind end of the Vagina, and for an interval they have no opening at all— the old one being lost, and the new one not yet being formed. No septal division is employed in this change ; but as the hind gut, when its cloacal opening is lost, re-establishes communication with the exterior by a downward growth, so the Mullerian ducts, when this cloacal opening becomes, obliterated, tunnel a new passage to the hind end.— The active agent in this growth are two epithelial masses-that l1ave been described by Berry Hart as the Wolfﬁan bulbs, but to give this name to them is to give a deﬁnite idea as to their origin, and this seems to be by no means clear.”


Wood-Jones regards the female urethra “as a cloacal remnant in its simplest form,” and points out that it does not remain tubular throughout life, but it is for a time “ obliterated more or less completely by the proliferation of the vaginal bulbs.”


FIG. 3.— Model of female urethra and vagina, reconstructed from sections.



Certain tubules in connection with the female urethra have been described by Skene as the homologues of the prostate ducts in the- male. The homology of the urethral glands which are found in the neighbour- hood of the vestibule with the prostate was assumed by Virchow as early as 1853. The embryological researches of Tourneaux confirmed this conjecture. He also stated that the glands in the adult female possess a structure which corresponds with that of the prostate in a ﬁve or six months old embryo.

J. Grifﬁths says: “Any structure in the female, homological with the prostate in the‘ male, must be sought near the fore-part of the urethra, and its immediate neighbourhood in the small mucous glands which are there found.” Sir J. G.’ Simpson, on Hermaphrodism, says : “ If we are to ﬁnd a true prototype in the female of the prostate gland in the male, We shall probably detect it ‘in the follicular glands and structures that exist so abundantly in the course and at the extremity of the female urethra.” Gustav Pallin examined a female foetus of three months, criticising, in the light of his observations, the old contention as to whether, the ducts corresponding to the male prostate open into the urethra or vagina. He says: “ This embryo affords a decision in favour of neither of these views ; that is, they (the ducts) appear to open exactly at the boundary between the two; the ducts have almost the same appearance as those already described on the ventral wall of the urethra of a'male embryo of four months . . . . hence it is now clear that the lower urethral glands of the female are not homologous with the whole prostate, but only with those glands developed from the cephalic and ventral prostatic positions : and as far as the last are concerned they belong to the urethra proper, and not to the urogenital sinus ” (translation). '



FIG. 4. M .Pr., musculus prostaticus ; Cr.U.£ crista urethralis ; Pr.S., prostatic sinus; A.D., P.D., L.D., prostaic ducts; M. D., Miillerian ducts; W.D., Wolﬂian duct. '



The foregoing quotations from the works of various observers brieﬂy summarise our knowledge regarding the. homologies of certain structures found in the female with the prostate in the male."


The present writer reconstructed a model of the female urethra and vagina, together with the glandular tissue in relation to these organs (ﬁg. 3). The foetus from which the sections were made was three and a half months old. The urethra of this specimen is enveloped by a fusiform swelling like that of a male prostate, and, like it, it is composed of a stroma of ﬁbro- muscular tissue enclosed in a capsule derived from -the pelvic fascia; and within this capsule there is a well-developed musculus prostaticus, the sphincter urethrae of later development (ﬁg. 4c). The model shows an exuberant growth of glandular tissue, chieﬂy from the postero-lateral walls of the urethra, as well as also from the anterior wall. Microscopically, the ducts cannot be distinguished from those of the male prostate of the same age.




FIG. 5. —Section through prostatic sinuses, lettering as in ﬁg. 4.


On comparing the ducts which grow out from the male urethra to form the prostate with those which are derived from the female urethra, we ﬁnd that they correspond -in striking detail as regards their disposition and arrangement, e.g. the ducts of the “ third lobe” are quite as well developed as in ‘the male of a corresponding age; and the inferior horizontal ducts are also characteristic features; and further, the mode of separation of the ducts, as detailed in a previous paper on the prostate in the male, is the same in the female; again, the form of the female urethra at three and a half months is closely similar to that of the male of the same age. The crista urethralis is Well marked (ﬁgs. 4 and 5). The grooves on either side of the crista urethralis forming the prostatic sinus of the male are well deﬁned in the female, and, like the former, receive the prostatic ducts. There can, therefore, be no doubt but that the glandular organ surrounding the whole length of the female urethra is the homologue of the prostate in the male; this indicates that the female urethra is the counterpart of the whole of the prostatic urethra in the male; the corresponding parts in the sexes are represented diagrammatically in ﬁg. 1.



FIG. 6.—Diagrams of growth of female prostate.


The reconstructed model shows a solid vagina in the female, extending downwards from the level of the attachment of the genital cord. Trans- verse sections through the middle of the female urethra, as also through the middle of the male prostatic urethra, show the coalesced Miillerian ducts, with the Wolﬂian ducts entering the urethra (ﬁgs. 4 and 5), so that, as regards the relations of the genital cord to the urethra, the homologies are complete. ‘ The vagina cannot be fully accounted for in the male‘ genitoeurinary economy. The vagina, whatever its origin may be, is an organ that is probably peculiar to the human i female; it ‘does not seem to appear in the male. I ﬁnd, with Wood-Jones, that no septum exists between the urethra and vagina, and that the vagina is for a great part of foetal life a solid and not an open canal; I ﬁnd, further, that early in the history of the female embryo the Miillerian and Wolﬁian ‘ducts open into the urethra as they do in the adult male. The specimens I have examined show that the vagina is a solid organ; its lining wall is distinct from the contained cellular mass with which it is ﬁlled. The cells lining_ the vagina are columnar; those found within its cavity are large polyhedral structures; further, they are not like the lining cells of the Wolfﬁan ducts; they are probably proliferated from the cells lining the vagina.



FIG. 7.—Transverse section through urogenital cleft of fmtus of 35 months. U., uterus; V., vagina; B.G., Bartholin’s gland; L., labia; Ves., vestibule. ‘




The vagina is at ﬁrst a caecal diverticulum from the inferior wall of the coalesced Miillerian ducts, and is ﬁlled, with the cells mentioned above, The blind end of the diverticulum, passing beyond its original attachment to the urethra, reaches towards the surface-epithelium, blends with it, and forms with it a vaginal membrane (the hymen) (ﬁg. 6), in the same manner as the cloacal membrane is formed.


It isprobable that the growth of this diverticulum is contingent upon, the occlusion of the Miillerian ducts Where they open into the urethra; The vagina shows no tendency to be a double organ except at its distal

At this stage of development, three and a half months, the urethra is a very patent canal. With the disappearance of the glandular tissue of the prostate, the capsule, with its contained striped muscle, persists; and the former is the source of the ﬁbrous basis of the urethra, the latter con- stitutes the sphincter urethrae of the adult female urethra.

==Bibliography==

DIXON, A. F., Textbook of Anatomy, edited by Cunningham, 1909.

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EVATT, E. J ., Jowrn. of Anat., vol. xliii., 1908, “A Contribution to the Development of the Prostate.”

GRAY, Anatomy, Descriptive and Applied, edited by Howden, 1909.

GRIFFITHS, JOSEPH, Journ. of Anat., vol. iii., new series, 1888-1889, “Observa- tions on the Anatomy of the Prostate” ; and Journ. of Anat. and Phys, vol. v., 1890- 1891, “ Observations on the Urinary Bladder and Urethra.”

KEIBEL, F., “ Zur Entwickelungsgeschichte des Menschlichen Urogenital- apparatus,” Archtv f. Anat. u. Entwicln, 1896, pp. 55-156. »

KEIBEL, F., “ Noch einmal zur Entwickelung des Urogenitalsystem, z'bz'd., 1897, p. 201. ‘

WooD-JONES, F., “The Nature of the Malformations of the Rectum and Urogenital Passages,” Britzsh Medical Journal, Dec. 17, 1904.

PALLIN, GUSTAF, Archie: fit?‘ Anatomic’, 1901, “Anatomic und Embryologie der Prostata und der Samenblasen.” (In the Archiv a very complete literature on the development of the prostate will be found.)


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