THE EP-OOPHORON AND PAR-OOPHOROK 1315 



which joins the lateral angle of the uterus. The last portion of the canal, or pars 

 uterina, is embedded in the substance of the uterine wall, which it traverses to 

 reach the cavity of the titerus (Fig. 1032, B). The opening into the uterus, or 

 ostium uterinum tubse, is smaller than the ostium abdominale, being about 1 mm. in 

 diameter. The lumen of the canal gradually increases in width as it is traced out- 

 wards from the uterus towards the ovary. 



Course of the Uterine Tube. Traced from the lateral angle of the uterus the 

 uterine tube is directed at first horizontally in a lateral direction towards the uterine 

 extremity of the ovary. It then passes upwards in relation to the medial side of 

 the mesovarian border of the ovary, until it reaches the tubal extremity, where, 

 arching backwards, it descends along the posterior or free border, resting against 

 the medial surface of the ovary (Fig. 1028). As the uterine tube describes this loop 

 it often covers almost the entire medial surface of the ovary. The fimbriated 

 end of the tube is applied against the free border and inferior part of the medial 

 surface of the ovary, and from it the ovarian fimbria pass upwards to gain attach- 

 ment to the tubal extremity of the gland. 



The fimbriated end of the uterine tube lies in the abdominal cavity until the ovary in its 

 descent has entered the pelvis. 



Structure of the Uterine Tubes. The wall of each tube, which is surrounded 

 by a covering of peritoneum or tunica serosa, is composed of a number of concentric layers 

 or coats. Immediately beneath the peritoneum is a layer of loose connective tissue, 

 the tunica adventitia, in which lie many vessels and nerves. Beneath this is the tunica 

 muscularis, composed of two strata of smooth muscle fibres a more superficial thin 

 stratum of longitudinally arranged fibres, the stratum longitudinale, and a deeper 

 thicker layer, the fibres of which are circularly disposed, the stratum circulare. Deeper 

 is a submucous layer or tela submucosa, and then the lining membrane or tunica mucosa. 

 In the part of the tube near the uterus the muscular layer is thicker than towards the 

 other end, and in the isthmus it forms the chief part of the wall. The mucous membrane, 

 on the contrary, is thickest towards the fimbriated end, and here it forms the chief part 

 of the tube wall. The stratum of circular muscle fibres is especially well developed near 

 the uterus. The mucous membrane is thrown into numerous longitudinal folds, the plicae 

 tubarise, which in the ampulla are exceedingly complex, the larger ones being beset on 

 the surface by smaller folds. In transverse sections of this part of the tube the folds of 

 the mucous membrane look like large branching processes projecting into, and almost 

 completely filling up, the lumen of the tube. The mucous membrane is covered by a 

 ciliated epithelium, the cilia of which tend to drive the contents of the tube towards the 

 uterus. The epithelium is continuous with that of the uterus, and at the fimbriated end 

 joins the peritoneum. 



Vessels and Nerves of the Uterine Tube. The uterine tube receives its chief blood-supply 

 from a ramus tubarius of the uterine artery, but it also receives small branches derived from the 

 ovarian artery. The veins of the tube pour their blood partly into the uterine and partly into 

 the ovarian veins. The lymph-vessels join the lumbar group of lymph-glands. The nerves are 

 derived from the plexus that supplies the ovary, and also from the plexus in connexion with the 

 uterus. The afferent fibres appear to belong to the eleventh and twelfth thoracic and the first 

 lumbar nerves. 



EP-OOPHORON AND PAR-OOPHORON. 



These are two rudimentary structures found between the layers of the broad 

 ligament. 



The ep-obphoron (O.T. parovarium ; often called the organ of Kosenmiiller) lies in 

 the mesosalpinx between the uterine tube and the ovary. In the adult it consists 

 of a number of small rudimentary blind tubules lined by an epithelium. One of 

 these tubules the ductus epoophori longitudinalis (O.T. duct of Gartner) lies 

 close to, and runs nearly parallel with, the uterine tube. It is joined by a number 

 of the other tubules, or ductuli transversi, which enter it at right angles, from the 

 neighbourhood of the ovary. The longitudinal duct is a persistent portion of the 

 Wolffian duct, and represents the canal of the epididymis in the male, while the 

 tubules which join it are derived from the mesonephros and represent the efferent 

 ductules of the testis (and probably also the ductuli aberrantes of the duct of the 

 epididymis). The ep-oophoron is best seen when the part of the broad ligament 

 in which it lies is held up to the light. 



84 a 



