MENSTRUATION. 



953 



m 



FIG. 363. Sagittal Section through the Normal Endometrium, m, to- 

 gether with a Portion of the Contiguous Muscular Layer, m\. 



With regard to the connection between ovulation and therdischarge of blocd 

 from the endometrium, there are at the present time two views. Pfiuger[ con- 

 siders the bloody exfoliation of the superficial layer of the endometrium as a 

 preparatory freshening 

 of the tissues (in the 

 surgical sense) occur- 

 ring physiologically, as 

 a result of which it is 

 rendered capable of unit- 

 ing firmly by adhesion 

 (as in case of thrombosis 

 or cicatrization) with the 

 ovum that finds its way 

 into the uterus, so that 

 the ovum is further 

 nourished from the new 

 lining membrane of the 

 uterus like a developed 

 or adherent part. This 

 view is entirely at vari- 

 ance with another, ac- 

 cording to which there 

 develop within the uter- 

 us marked engorgement, 

 sponginess, and swelling 

 of the mucosa, under 

 normal conditions, even 

 before the discharge of the 

 ovum from the follicle, in con- 

 sequence of a sympathetic 

 formative process. The en- 

 dometrium thus prepared is 

 designated the menstrual de- 

 cidual membrane. From this 

 point of view it is capable, as 

 a suitable place of incubation, 

 of receiving an impregnated 

 ovum. If, however, the ovule 

 has not been impregnated and 

 if, therefore, it is lost after its 

 passage through the genital 

 canal, destruction of the uter- 

 ine mucosa takes place with 

 hemorrhage, as already de- 

 scribed. Accordingly, the 

 hemorrhage from the uterine 

 mucosa would be a sign of 



the nonoccurrence of pregnancy. The mucosa undergoes destruction because 

 it could not be utilized for the time being, and the menstrual hemorrhage is, 



therefore, an external 

 sign that the discharged 



Ovarian stroma. ovum has not been im- 



pregnated. Accordingly, 



External tunic of follicle. pregnancy, that is the 



development of the fetus 

 in the uterus, must be 

 reckoned not from the 

 last menstruation that 

 occurred, but from the 

 first menstruation that 

 was absent. 



With the rupture of 

 the follicle, the cumulus 



oophorus first is detached from the wall of the latter, the most superficial 

 portion of the follicle, designated the stigma, becomes thin, its vessels 



FIG. 364. Horizontal Section of the Normal Endome- 

 trium (after Orthmann). 



Vessel between the external tunic of the 

 follicle and the tunica propria. 



... Folded and hypertrophied tunica propria. 



FIG. 365. Fresh Corpus luteum (after Balbiani). 



