SOURCE AND CHARACTER OF MENSTRUAL CHANGES 725 



flow. On the other hand, in almost all subjects examined after death, of 

 which there is record, rupture of the follicle appears to have taken place 

 before the commencement of the menstrual flow. 



However, the presence of the ovaries seems necessary for the performance 

 of the menstrual function; for women do not menstruate when both ovaries 

 have been removed by operation. See page 46 for a discussion of the 

 functional effects of removal of the ovary. 



Source and Character of Menstrual Changes. The menstrual periods 

 usually occur at intervals of a lunar month, the duration of each being from 

 three to six days. In some women the intervals are so short as three weeks 

 or even less; while in others they are longer than a month. The periodical 

 return is usually attended by pains in the loins, a sense of fatigue in the lower 

 limbs, and other symptoms, which vary extremely in different individuals. 



The menstrual discharge is a thin sanguineous fluid, and consists of blood, 

 epithelium, and mucus from the uterus and vagina. The menstrual flow 

 is preceded by a general engorgement of all the pelvic organs with blood. 

 The cervix and vagina become darker in color and softer in texture, and 

 the quantity of mucus secreted by the glands of the cervix and body is in- 

 creased. The uterine mucous membrane is swollen and the glands are 

 enlarged. The discharge of blood, the source of which is the mucous 

 membrane of the body of the uterus, is probably associated with uterine 

 contractions. There is great difference of opinion as to whether or not 

 any of the uterine mucous membrane is normally shed during the process 

 of menstruation. John Williams believes that the w r hole of the mucous 

 membranes of the body of the uterus is thrown off at each monthly period, 

 forming a true decidua menstrualis, figure 496, while Moricke and others 

 believe that the mucous membrane remains intact. Leopold believes 

 that red blood corpuscles escape from the congested capillaries and under- 

 mine the superficial epithelium, and that in this way the superficial layer of 

 the mucous membrane is eroded and subsequently regenerated. There 

 is a period of regeneration followed by a period of rest before the next 

 repetition. Minot distributes the variations in time as follows: 



Tumefaction '. 5 days 



Menstrual discharge 4 days 



Restoration of mucosa 7 days 



Period of rest 12 days 



The menstrual period is often accompanied by profound disturbances in 

 other parts of the body, especially of the vascular and of the nervous systems, 

 and of the nutritive processes. 



Corpus Luteum. Immediately before, as well as subsequent to, the rupture 

 of an ovarian follicle and the escape of its ovum, changes ensue in the interior 

 of the follicle, which result in the production of a yellowish mass, termed a 

 corpus luteum. 



