2U 



THE ESSENTIALS OF HISTOLOGY. 



layer, on the other hand, is thick ; its fibres run in different directions, 

 but chiefly circularly, and it is prolonged internally into the deeper part 

 of the mucous membrane, the extremities of the uterine glands extending 

 between and amongst its fibres. It is imperfectly separated from the 

 thinner external layer by the ramifications of the larger blood-vessels, 

 and represents a much-hypertrophied muscularis mucosoe. 



FIG. 248. SECTION OF THE MUCOUS MEMBRANE OF THE BABBIT'S UTERUS. 



s, serous layer; l.m., longitudinal muscular fibres; c.m., circular muscular fibres of the 

 muscular coat ; a, areolar tissue, with large blood-vessels ; m.m., muscularis mucosse ; 

 m, mucous membrane. 



3. A mucous membrane, which is very thick and is composed of soft 

 connective tissue containing a large number of spindle-shaped cells. It 

 contains long, simple, tubular glands, which take a curved or con- 

 voluted course in passing through the membrane. They are lined 

 by ciliated epithelium continuous with that which covers the inner 

 surface of the mucous membrane. In the cervix the mucous membrane 

 is marked by longitudinal and oblique ridges, and the glands are shorter 

 than those of the body of the uterus. Near the os uteri the epithelium 

 becomes stratified and overlies vascular papillae of the corium. The 

 mucous membrane is exceedingly vascular, and it also contains a large 

 number of lymphatic vessels. 



