216 NORMAL HISTOLOGY. 



orifices of these glands sometimes become occluded, causing a cys- 

 tic dilatation of the acini, due to accumulated secretion, " ovula 

 Nabothi." 



The muscular and other tissues of the uterine wall undergo 

 hypertrophy during pregnancy, the individual muscular fibres be- 

 coming as much as thirty times their original bulk in the non-preg- 

 nant uterus. The bloodvessels also enlarge and acquire thicker 

 walls. These retain much of this increase of size, even after the 

 involution of the uterus following parturition, but the muscular 

 fibres suffer a partial fatty degeneration, which restores them to 

 nearly their original condition. 



4. The Vagina (Fig. 192). The subepithelial fibrous coat of the 

 vagina is covered with small papilla?, which project into the epithe- 



FIG. 192. 



ct 







-"I--V 



Portion of a longitudinal section of the vaginal wall. (Benda and Guenther's Atlas.} a, 

 stratified epithelium ; b, subepithelial areolar tissue ; c, muscularis mucosse ; d, areolar 

 submucosa containing vascular trunks ; e, muscular coat. Outside of the latter is the 

 ill-defined fibrous coat, not represented in the figure. 



Hum. Outside of this coat is one of smooth muscular tissue, which 

 is not clearly divisible into layers, but in which the inner fibres are 

 chiefly circular, forming an imperfectly defined muscularis mucosse, 

 while the outer have a longitudinal direction, and may be regarded 

 as the true muscular coat of the vagina. Outside of the muscular 



