THE UTEKUS 417 



In the human uterus the arrangement of muscle fibres is 

 much less regular, but follows a similar plan, though there is no 

 distinct subdivision into layers. Nevertheless, careful examina- 

 tion reveals three indistinct strata which are intimately blended 

 with one another. The outermost of these indistinct layers con- 

 sists of irregularly disposed longitudinal fibres, the stratum supra- 

 vasculare. This layer is in most parts very 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 fibres, 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, 





Fio. 337. TRANSECTION THROUGH THE BODY OF THE HUMAN UTERUS. 



<7, blood vessels ; Z, lumen ; W, broad ligament ; Im, longitudinal muscle ; w, circular 

 muscle (the fibres are mostly oblique) ; , serous coat ; tp, mucosa. Hematoxylin and 

 eosin. x 2. (After Sobotta.) 



from which both the mucous and muscular coats are supplied. 

 This broad middle layer is therefore known as the stratum vas- 

 culare. The inner portion of this second layer passes insensibly 

 into a thin innermost stratum submucosum, which again contains 

 many longitudinal fibres, and upon which the mucosa directly rests. 

 The uterine mucosa is of considerable thickness (1 to 3 mm.). 

 It is clothed with epithelium, and its tunica propria contains 



numerous tubular glands. 

 28 



