254 



NORMAL HISTOLOGY. 



THE OVIDUCTS. 



The oviduct or Fallopian tube, also called the tuba uterina, is, in 

 principle, the excretory canal of the sexual gland, since it conveys the ova 

 liberated from the ovary to the uterus, into which it opens. The relation 

 between the ovary and its duct is exceptional, in that these organs are not 

 continuous but only in apposition, the ova liberated from the ruptured 

 Graafian follicles finding their way into the expanded end of the oviduct. 

 This canal, one on each side of the body, lies within the free border of the 

 broad ligament and extends laterally from the uterus to the ovary, in relation 

 with the mesial surface of which it ends after repeated windings. The entire 



FIG. 304. Transverse section of oviduct near outer end of ampulla. X 35- 



length of the tube is about 11.5 cm. (4^ i n -)> its diameter increasing from 

 3-4 mm. at the isthmus, next the uterus, to from 6-8 mm. at the outer limit 

 of the ampulla, where the canal suddenly expands into the terminal trumpet- 

 shaped infundibuhim. The mucous membrane lining the oviduct is thrown 

 into longitudinal folds, which become progressively more marked towards 

 the outer end, so that cross-sections of the ampulla present a lumen of 

 complex outline owing to the projection of primary and secondary plications 

 (Fig. 304). At the irregularly notched or fimbriated margin of the infun- 

 dibulum, the mucous lining of the tube is directly continuous with the 

 peritoneum. The exceptional relation of the tubal mucosa to the serous 

 membrane, this being the only place in the body where a mucous tract 

 directly communicates with a serous sac, is a persistence of the similar 

 relation of the embryonal Miillerian duct, from which the oviduct is directly 

 derived. 



