CHAPTER VII. 

 STUDY OF THE UTERUS AND THE FETAL APPENDAGES OF MAN. 



Histology of the Uterus. 



In most mammals the uterus is double. This is the case in the pig, the 

 rabbit, and the mouse, the three species which furnish material for the practical 

 study as planned in this book. In these animals each uterus is a long, more or 

 less cylindrical tube. In primates the double uterus exists only during very early 

 embryonic stages, after which the two are found united into a single median 

 uterus. The mammalian uterus is always lined by a mucous membrane, con- 

 sisting of a superficial epithelium which forms glands, and of a deeper layer of 

 reticulate connective tissue, in which there are lymph spaces, nerves, and a fairly 

 abundant blood supply. The mucous membrane is subject to very marked periodic 

 changes in structure. It is enclosed by the muscular layers of the organ, the 

 muscle-fibers being of the smooth type. In animals with double uteri the muscle- 

 fibers form two distinct layers, an inner circular and an outer longitudinal layer. 

 In the primate 'uterus the disposition of the fibers is far more complicated, and 

 the two distinct layers cannot be identified. The surface of the uterus, wherever 

 it is free, is covered by a layer of peritoneum which consists of a layer of flattened 

 epithelial cells and a thin underlying layer of fibrillar connective tissue. 



The human uterus at birth has a mucosa which is about 0.2 mm. thick. 

 The mucosa is soft, pale gray or reddish gray in color; it consists of a covering 

 of ciliated epithelium and a connective-tissue layer. It is without glands, the 

 glands not appearing usually until the third or fourth year, and developing very 

 slowly up to the age of puberty. 



The development of the human uterine glands is accompanied by remarkable 

 and complex changes of A he epithelium.* The adult glands, as shown by figure 225, 

 are much branched, and the branches occasionally anastomose with one another. 

 The model, from which the figure is taken, demonstrates that the conception of the 

 character of the uterine glands, which has hitherto prevailed, is very inadequate. 



Menstruation. 



The function of menstruation involves great changes in the mucosa of the 

 body of the uterus. We distinguish three periods: (i) tumefaction of the mucosa, 

 with accompanying structural changes, taking five days, or, according to Hensen, 



* Unpublished investigations by C. A. Hedblom, to whom I am indebted for the privilege of inserting figure 225. 



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