(>46 



UTERUS AND ITS APPENDAGES. 



thinner. He found the thickness of the ute- 

 rine walls, three weeks after conception, 6'" ; 



Fig. 444. 



During these changes, which take place in 

 the uterine body in the course of pregnancy, 

 similar, but much slighter, alterations occur in 

 the cervix. For the latter, being only the ex- 

 cretory channel of the uterus, undergoes no 

 further modification than is necessary to pre- 

 p'are it for transmitting the foetus when fully 

 developed. Accordingly, in the early months 

 of gestation, while the body is rapidly en- 

 larging, the cervix undergoes but little change. 

 Its tissues, however, become slightly expanded, 

 so that the whole part is thicker, softer, and 

 more elastic than in the virgin state. The 

 margins of the os externum are consequently 

 rendered more cushiony, and the orifice itself 

 is enlarged. The canal of the cervix is also 

 widened, and the palmas plicatas become un- 

 folded, and project in the form of frill-like 

 expansions (fig. 446.) ; while an unusual ac- 

 tivity, occurring in the crypts and follicles, 

 by which these parts are covered, a tough 

 gelatinous secretion is poured out, which 



Fig. 445. 



Human gravid uterus at eiyht months. The vessels 

 have been injected, and tlie peritoneum removed from 

 the sides and fore-part of the uterus. (After IVm. 

 Hunter.) 



a, commencement of the cervix; bb, portion of 

 the body corresponding with the brim of the pelvis ; 

 cc, Fallopian tube concealing the ovary; dd, round 

 ligament ; e, hypogastric artery, and /, vein ; g, 

 spermatic artery, and h, vein. 



at the commencement of the third month, 5'" ; 

 at the commencement of the fourth month, 

 4'". At the end of the fourth month, in two 

 cases, 4"' ; in a third, 3"' at the upper, and 

 4'" at the lower part ; in a fourth, 5"'. At 

 five months, in one case, 3'"; in another, 2"' 

 superiorly, and 4"' inferiorly. At six and 

 seven months, rather less than 3'" ; at eight 

 months, in one case, 2'", and 2'" ; and in 

 another, 3"' above, and more than 4'" below. 

 At nine months, they appear to be still rather 

 thinner. 



In several uteri, which I have examined at 

 all stages of gestation, I have found the thick- 

 ness of the uterine walls exceedingly variable 

 in different instances, even at corresponding 

 periods of pregnancy, and particularly variable 

 also in different parts of the same uterus.* 

 According to my measurements, the extremes 

 of thickness range from 2'" to 9 /// . 



* This circumstance is remarkably exemplified 

 in prep. No. 3605, in the Museum of the .Royal 

 College of Surgeons, London. 



Os and cervix uteri in the eighth month of pregnancy. 



The os is surrounded by a broad disc of enlarged 

 cervical follicles filled with a gelatinous secretion. 

 The os is represented as seen from the vagina, va, 

 vaginal walls divided ; u, walls of uterus. Half the 

 natural size. (Ad Nat.) 



collecting here in the form of a plug, assists 

 in shutting out the uterine cavity and its 

 contents from contact of external air and 

 other influences. 



The increase in size of the os and cervix, 

 which is gradually progressive through the 

 whole of gestation, will be sufficiently ex- 

 pressed by comparing the dimensions of these 

 parts in their two extreme states. The virgin 

 cervix measures usually at the base 7 8"' in 

 its shorter, and 11 12'" in its transverse dia- 

 meter, and has an aperture of 3 V" wide. 

 It projects into the vagina to the extent of 

 V" (fig. 425). At the end of pregnancy, 

 the whole vaginal portion of the cervix would 

 fill a circle of 1^" diameter; the orifice 

 measures transversely 10 II"'; and that 

 part which formerly projected into the fornix 

 of the vagina, is now reduced nearly to the 

 level of the vaginal walls. 



During these changes, it is often observed, 

 especially in a first pregnancy, that, as gesta- 

 tion advances, the projection of the cervix 



