Henry Gray (18251861). Anatomy of the Human Body. 1918.
1107). By the fifth or sixth week this body forms an elongated spindle-shaped structure, termed the urogenital fold(Fig. 1106), which projects into the celomic cavity at the side of the dorsal mesentery, reaching from the septum transversum in front to the fifth lumbar segment behind; in this fold the reproductive glands are developed. The Wolffian bodies persist and form the permanent kidneys in fishes and amphibians, but in reptiles, birds, and mammals, they atrophy and for the most part disappear coincidently with the development of the permanent kidneys. The atrophy begins during the sixth or seventh week and rapidly proceeds, so that by the beginning of the fifth month only the ducts and a few of the tubules remain.
In the male the Wolffian duct persists, and forms the tube of the epididymis, the ductus deferens and the ejaculatory duct, while the seminal vesicle arises during the third month as a lateral diverticulum from its hinder end. A large part of the head end of the mesonephros atrophies and disappears; of the remainder the anterior tubules form the efferent ducts of the testis; while the posterior tubules are represented by the ductuli aberrantes, and by the paradidymis, which is sometimes found in front of the spermatic cord above the head of the epididymis (Fig. 1110,C).
FIG. 1107 Enlarged view from the front of the left Wolffian body before the establishment of the distinction of sex. (From Farre, after Kobelt.) a, a, b, c, d. Tubular structure of the Wolffian body. e. Wolffian duct. f. Its upper extremity. g. Its termination in x, the urogenital sinus. h. The duct of Müller. i. Its upper, funnel-shaped extremity. k. Its lower end, terminating in the urogenital sinus. l. The genital gland. (See enlarged image)
In the female the Wolffian bodies and ducts atrophy. The remains of the Wolffian tubules are represented by the epoöphoron or organ of Rosenmüller, and the paroöphoron, two small collections of rudimentary blind tubules which are situated in the mesosalpinx (Fig. 1108). The lower part of the Wolffian duct disappears, while the upper part persists as the longitudinal duct of the epoöphoron or duct of Gärtner1 (Fig. 1110,B).
FIG. 1108 Broad ligament of adult, showing epoöphoron. (From Farre, after Kobelt.) a, a. Epoöphoron formed from the upper part of the Wolffian body. b. Remains of the uppermost tubes sometimes forming appendices. c. Middle set of tubes. d. Some lower atrophied tubes. e. Atrophied remains of the Wolffian duct. f. The terminal bulb or hydatid. h. The uterine tube, originally the duct of Müller. i. Appendix attached to the extremity. l. The ovary. (See enlarged image)
The Müllerian Ducts.Shortly after the formation of the Wolffian ducts a second pair of ducts is developed; these are named the Müllerian ducts. Each arises on the lateral aspect of the corresponding Wolffian duct as a tubular invagination
Note 1. Berry Hart (op. cit.) 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 by these bulbs, aided by a special involution from below of the cells lining the urogenital sinus. He further believes that the lower third of the vagina is due to the coalescence of the upper portion of the urogenital sinus and the lower ends of the Wolffian ducts, and that the epithelial lining of the vagina is derived from the Wolffian bulbs. He also regards the colliculus seminalis of the male urethra as being formed from the lower part of the Wolffian ducts. [back]