CORPUS LUTEUM. 



783 



marked general disturbance, except a sense of lassitude, which may become 

 exaggerated if the discharge be unusually abundant. It has been noted, 

 however, by Rabuteau, that during the menstrual period the production of 

 urea is diminished more than twenty per cent., that the pulse becomes slower 

 and that the temperature falls at least one degree Fahr. (about half a de- 

 gree C.). 



If the mucous membrane of the uterus be examined during the menstrual 

 flow, it is found smeared with blood, which sometimes extends into the Fallo- 

 pian tubes. It is then much thicker and softer than during the intermen- 

 strual period. Instead of measuring about ^ of an inch (1/8 mm.) in thick- 

 ness, as it does under ordinary conditions, its thickness is fa to J of an inch 

 (4-2 to 6-4 mm.). It becomes more loosely attached to the subjacent parts, 

 is somewhat rugous, and the glands are very much enlarged. At the same 

 time there are developed, in the substance of the membrane, large numbers 

 of spherical and fusiform cells. This condition probably precedes the dis- 

 charge of blood by several days, during which time the membrane is gradu- 

 ally preparing for the reception of the ovum. There is also a fatty degenera- 

 tion of the different elements entering into the structure of the mucous 

 membrane, including the blood-vessels, this change being most marked at 

 the surface ; and it is on account of the weakened condition of the vascular 

 walls that the haemorrhage takes place. A short 

 time after the flow has ceased, the mucous mem- 

 brane returns to its ordinary condition. There is a 

 considerable desquamation of epithelium from the 

 uterus, with the flow of blood, during the menstrual 

 period. Sometimes, in normal menstruation, the 

 epithelium thrown off is in the form of patches. 



Changes in the Graafian Follicles after their 

 Rupture (Corpus Luteum). After the discharge 

 of an ovum, its Graafian follicle undergoes certain 

 retrograde changes, involving the formation of what 

 is called the corpus luteum. Even when the dis- 

 charged ovum has not been fecundated, the corpus 

 luteum persists for several weeks, so that, ovulation 



. * Fro. 285. Sections of two cor- 



occurrmg every month, several of these bodies, in vora lutea : natural size 



J (Kolliker). 



various stages of retrogression, may sometimes be i, corpus luteum eight days af- 



jppn in flip nvaripc ter conception ; a, external 



m aries ' coat of the ovary ; 6, stroma 



at the fifth 



For a certain time anterior to the discharge of 

 the ovum, there is a cell-proliferation from the 

 proper coat of the Graafian follicle, and probably 

 from the membrana granulosa, with a projection of 

 looped blood-vessels into the interior of the follicle. 

 This is the first formation of the corpus luteum. 

 At the time of rupture of the follicle, the ovum, with a great part of the 

 membrana granulosa, is discharged. Usually, at the time of rupture of the 

 follicle, there is a discharge of blood into its interior ; but this is not invaria- 



{ O r fi usuteuni elope f 



