77//'; oviDccrs 22.'^} 



!iiudi thicker in proportion to the lumen. Tlie ciha of the eohunnar 

 e])ithelial cells beat away from the ostium, so tiiat the egj? and 

 follicular fluid are propelled toward the uterus. The e])ithelial 

 lining may show variations in the a])i)earance of the eohunnar cells 

 at different periods of the ovarian cycle. 



The f7('/7/.s.— Regardless of its anatomical variations, whether 

 sim])lex, hicornis, or dui)lcx, the uterine structure is the same 

 fundamentally. At the end of the oxiduct the uterus begins as 

 an abruptly exi)ande(l tube containing the same three coats of tissue. 



Fig. 139. — Photograi>h of a section through the oviduct of a kitten near the ovary. 

 The mucosa is much folded. 



Ilowexer, the three divisions of adventitia, muscularis, and mucosa 

 are much more developed than in the preceding portion of the duct. 

 The adventitia is called the perimyometrium, the muscularis 

 becomes the myometrium, and the mucosa is called the endo- 

 metrium. (Figs. 140 and 141.) 



In the connective-tissue framework of the myometrium are many 

 types of connective-tissue cells, including an embryonic variety 

 capable of forming muscle cells in great numbers when pregnancy 

 occurs. In ]:)regnancy the myometrium increases many times its 

 size in the resting uterus, due to increase in cell numbers as well 

 as to increase in cell size. The connective-tissue fibers also increase 

 and there is a looser arrangement and more tissue juice. 



The uterus is interpreted usually as having no submucosa; the 

 connective tissue of the mucosa continues into that of the subjacent 



