1278 UROGENITAL SYSTEM 



a thin investment of connective tissue. From the main mass of each bulbus a 

 slender prolongation, the pars intermedia, extends anteriorly past the side of the 

 urethra, to form the glans clitoridis. 



The greater vestibular glands [gl. vestibularis major (Bartholini)] or glands of 

 Bartholin (fig. 1038) represent the bulbo-urethral glands of the male. They are 

 two small, compound tubular glands, situated one on either side immediately 

 posterior to the bulbi vestibuli. 



The single duct of each gland opens on the floor of the vestibule in the angle between the 

 hymen and the orifice of the vagina and a little posterior to the mid-transverse line of the latter. 

 Numerous small tubular glands occur in the integument forming the floor of the vestibule; 

 they are termed the lesser vestibular glands and are especially developed in the interval between 

 the urethral and vaginal orifices. 



The muscles of the female external genitalia (fig. 1038) correspond to the 

 perineal muscles of the male (see Section IV). There are two transverse perineal 

 muscles, which have the same relations as in the male, and two ischio-cavernosi, 

 which are related to the crura clitoridis just as those of the male are to the crura 

 penis. The bulbo-cavernosi, however, present somewhat different relations, each 

 being band-like in form, arising from the central point of the perineum and ex- 

 tending forward past the orifice of the vagina, over the greater vestibular gland 

 and the bulbus, to form with its fellow of the other side a tendinous investment of 

 the body of the clitoris. The two muscles act as a sphincter to the vagina and 

 are sometimes termed the sphincter vagince. 



The urethra. — The urethra of the female [urethra muliebris] (figs. 1034, 1036) 

 corresponds only to the prostatic and membranous portions of the male and is a 

 relatively short canal, measuring from 3.0 to '4.0 cm. in length. At its origin from 

 the bladder it lies about opposite the middle of the symphysis pubis and thence 

 extends downward and slightly forward to open into the vestibule between the 

 glans clitoridis and the orifice of the vagina. Its posterior wall is closely united 

 with the anterior wall of the vagina, especially in the lower part of its course where 

 it forms the urethral carina of the vaginal wall; laterally and anteriorly it is sur- 

 rounded by the pudendal plexus of veins. 



Structure. — Its walls are very distensible, and are lined by a mucous membrane with 

 numerous longitudinal folds, one of which on the posterior side is more prominent and is 

 termed the crista urethralis. The mucosa contains numerous smaU glands [gl. urethrales], 

 a group of which on each side is drained by the inconstant ductus paraurethralis. External 

 to the loose submucosa is a sheet of smooth muscle, whose fibres are arranged in an outer 

 circular and an inner longitudinal layer, a rich plexus of veins lying between the two and 

 giving the entire sheet a somewhat spongy appearance. The circular fibres are especially 

 developed at the vesical end of the canal, forming there a strong sphincter, and striped muscle 

 fibres, derived from the bulbo-cavernosus, form a sphincter around its vestibular orifice. The 

 female urethra differs from that of the male in not being enclosed within a prostate gland; but 

 what are probably rudiments of this structure are to be found in the groups of urethral glands 

 drained by the paraurethral ducts. 



Vessels and nerves. — The arteries supplying the external female genitalia are the internal 

 and external pudendals, and the veins terminate in corresponding trunks. The lymphatics, 

 which are very richly developed, drain for the most part to the inguinal nodes; those from the 

 urethra pass to the iliac nodes. The nerves are partly sympathetic and partly spinal; the former 

 are derived from the hypogastric plexus, the latter principally from the pudendal, the anterior 

 portions of the labia majora being supplied by the ilio-inguinal and the external spermatic 

 branch of the genito-femoral. 



DEVELOPMENT OF THE REPRODUCTIVE ORGANS 



It has already been pointed out (p. 1267) that during development a transitory excretory 

 organ, the mesonephros or Wolffian body, reaches a high degree of development, and its duct, 

 the Wolffian duct, opens into a cloaca or common outlet for the intestinal and urinary passages. 

 The me.soncphroH forms a strong projection from the posterior wall of the abdomen into the 

 body cavity, and on the medial surface of the peritoneum which covers it a thickening appears 

 which is termed the genital ridge. The upper part of this ridge becomes the ovary or testis, 

 as the case may be, while the remainch^r of it becomes the ovarian and round ligaments in the 

 female and the guhernaculum testis in the male. 



As the ovary or testis develops the tubules of the upper part of the Wolffian body enter 

 into relation with it, forming, indeed, in the case of the testis, a direct union with the semin- 

 ferous tubules. The Wolffian body then becomes divisible into a reproductive and an excretory 

 portion, and, when the metanephros or permanent kidney develops, the latter portion degene- 

 rate.s, leaving only a few rudiments, such as the paroophoron in the female (p. 1209) and the vas 

 aberrans and paradidymis (p. 1257) in the male. The reproductive portion also becomes nnich 

 reduced in the female, persisting as the tubules of the epoophoron (p. 1269), but in the male it 



