CHANGES IN THE NON-PREGNANT UTERUS 83 



As a consequence of these changes the mucosa becomes con- 

 siderably increased in thickness. Thus, if a woman who had 

 been menstruating regularly dies shortly before the expected 

 approach of a menstrual period, the thickness of the mucous 

 membrane is often as much as one-sixth of an inch at its thickest 

 part, as compared with a thickness of from one-tenth to one- 

 twentieth of an inch in women who died within ten days 

 after the cessation of the flow.^ Leopold ^ has described a 

 growth so considerable that the uterine cavity, prior to the stage 

 of bleeding, becomes almost completely obhterated. 



It should be mentioned, however, that according to some 

 authors the amount of pre-menstrual growth in the uterine 

 mucosa is very slight, while Oliver ^ seems to be doubtful whether 

 any growth occurs at all, stating that he has made an examina- 

 tion of uteri at various pre-menstrual and menstrual stages, 

 and has failed to find any evidence of changes in the mucosa 

 tissue apart from those directly associated with the phenomena 

 of bleeding. Westphalen's view appears to be similar ; for, 

 according to this observer, there is no multiphcation of nuclei 

 during this stage, the pre-menstrual swelling being brought 

 about entirely by the serous saturation of the stroma. 



The Destructive Stage. — At the close of the constructive 

 period the blood leaves the capillaries and becomes extra- 

 vasated freely in the stroma, but there has been some dispute 

 as to how this process is effected. It has been suggested that 

 the blood transudes through the walls of unruptured capillaries 

 under the influence of congestion, or that permanent openings 

 exist from the vessels into the uterine glands, these being closed 

 normally by muscular contraction ; * but the belief now generally 

 held is that, whereas the walls of many of the congested vessels 

 break down under pressure, and so freely admit of the exit 

 of the blood corpuscles into the mucosa tissue, haemorrhage also 

 takes place partly by diapedesis. Engelmann,^ Williams,^ and 



• Galabin, A Mwrmal of Midwifery, 6th Edition, London, 1904. 



^ Leopold, " Untersuchungen Uber Menstruation und Ovulation," Arch, 

 f. Oyndlc., vol. xxi., 1883. 



^ Oliver, "Menstruation; its Nerve Origin," Jour. Anat. aiul Phys.. vol. 

 xxi., 1887. ■* Galabin, loc. cit. ' Engelmann, loc. cit. 



' Williams (Sir J.), " The Mucous Membrane of the Body of the Uterus," 

 Obstet. Jour. Gt. Britain vols. iii. and v., 1875 1877. 



