THE OVIDUCT 



413 



mucosa is greatly folded, the primary rugae possessing small sec- 

 ondary folds which extend in all directions, and by their very com- 

 plexity nearly obliterate the otherwise broad lumen. In the 

 fimbriated portion the folds of the mucosa are continued into the 

 fimbriae, at the margin of which the columnar epithelium of the 

 oviduct becomes directly continuous with the serous endothelium 

 of the peritoneum investing the outer surface of the tube. 



FIG. 334. FROM A TIIANSECTION OF THE AMPULLA OF THE HUMAN OVIDUCT. 



One of the four major folds is included in the figure, a, mucosa ; J, muscular coat. 



Hematein and eosin. Photo, x 33. 



The mucosa is lined by columnar epithelium, arranged either in 

 a simple or pseudo-stratified manner, the greater portion of whose 

 cells are provided with cilia. The ciliary motion is directed toward 

 the uterus. The epithelial layer covers all the folds of the mucosa 



