THE FEMALE REPRODUCTIVE ORGANS 



529 



thin, and is best developed opposite the margin of the lateral ligament 

 and in the cervix uteri. Within this is a broad layer of interlacing 

 bundles of more or less circular fibers, which, from the slight obliquity 

 of their course, frequently cross each other at acute angles. Inter- 

 mingled with these circular bundles are many large blood-vessels, from 

 which both the mucous and muscular coats are supplied. This broad 

 middle layer is therefore known as the stratum vasculare. The inner 



FIG. 464. TRANSECTION THROUGH THE BODY OF THE HUMAN UTERUS. 



g, blood-vessels; I, lumen; II, broad ligament; Im, longitudinal muscle; m, circular 

 muscle (the fibers are mostly oblique); s, serous coat; tp, mucosa. Hematoxylin 

 and eosin. X 2. (After Sobotta.) 



portion of this second layer passes insensibly into a thin innermost 

 stratum submucosum, which again contains many longitudinal fibers, 

 and upon which the mucosa directly rests. 



The uterine mucosa, or endometrium, is of considerable thickness 

 (1 to 3 mm.). It is clothed with epithelium, and its tunica propria con- 

 tains numerous tubular glands. 



The epithelium is of the ciliated columnar type, and consists of a 

 single row of cells. Apparently not all of its cells are provided with 

 cilia, areas of ciliated alternating with groups of non-ciliated epithelium. 

 The epithelial layer is continuous with the epithelium of the uterine 

 glands; in the region of the external os uteri it is replaced by the strati- 

 fied squamous epithelium of the vaginal mucosa. Ofttimes, and espe- 



