UTERINE TUBES. 



295 



development of large embryos within it is not a rare occurrence. The 



epithelium is chiefly simply columnar and ciliated, the stroke of the cilia 



being toward the uterus. Small 



areas of flat non-ciliated cells may 



occur near the infundibulum and 



non-ciliated cells have been found in 



the isthmus. The tunica propria is 



a vascular tissue often containing 



lymphocytes. It extends into the 



folds. In some places the presence 



of strands of longitudinal smooth 



muscles (a muscularis mucosae) 



separates the mucosa from a sub- 



mucosa. The muscularis consists 



of a thick inner layer of circular 



337. 



A, XEAR ITS FIMBRIATED END; B, NEAR THE 

 UTERUS. (After Orthmann.) 



fibers and a thin outer longitudinal 



layer. The layers are thin toward the infundibulum where the longitudi- 

 nal fibers may be absent. The loose inner tissue of the serosa is 

 sometimes called the adventitia. Abundant elastic fibers occur in it, and 



\ \ 



\ Longitudinal muscles. 

 Blood vessels. 



Circular muscles. 



Mucosa. 

 FIG. 338. CROSS SECTION, NEAR THE AMPULLA, OF A UTERINE TUBE FROM AN ADULT WOMAN. 



