156 



BIOLOGY OF THE LABORATORY MOUSE 



epithelium and have a spiral course deep in the mucosa. Occasionally they 

 may penetrate into the muscular layer. The lamina propria consists of 

 reticular tissue and contains many small polyhedral cells with relatively 

 large, round nuclei. Lymphocytes are present and are especially numerous 

 near the muscle wall. The mucosa (the epithelium, uterine glands and the 



Lumen of uterine horn 



Lumen of corpus uteri 



4i> Vaginal fornix 



Cervix 



^^^„„„ Vagina 



Fig. 8o. — Transverse section of the uterine horns, corpus uteri, cervix and vagina. 



(X30.) 



lamina propria) of the non-pregnant uterus is called the endometrium. It 

 is well supplied with blood vessels. The endometrium is elevated into 

 circular folds. The small polyhedral cells of the endometrium change 

 during pregnancy into large epithelioid decidual cells. 



The myometrium surrounding the mucous membrane consists of a 

 compact ring of circularly arranged smooth muscle fibers, outside of which a 

 layer of loose connective tissue containing large blood and lymph vessels 



