224 



THE FEMALE REPRODUCTIVE SYSTEM 



miisciilaris region. The mucosa or endometrium undergoes remark- 

 able modifications in cyclical, or seasonal, periods. (Fig. 141.) In 

 humans, a series of changes are repeated each lunar month of the 

 productive period if pregnancy does not occur. During each of these 



Fig. 140.— Photograph of a section through the resting uterus of the rabbit. The 

 endometrium is thrown into several broad folds and many shallow tubular glands 

 occur in it near the lumen. The dark band surrounding the endometrium is the 

 myometrium. At the left the connective tissue and blood vessels of the mesentery 

 are shown continuing with the perimyometrium. 



Fig. 141. — Uterus of the cat in heat, showing glandular endoiiietriiun and broad 



myometrium. 



