628 



UTERUS AND ITS APPENDAGES. 



that of the external surface. But whilst the 

 anterior and posterior walls exhibit an average 

 and nearly uniform thickness of about 6''', 

 that of the lateral boundaries and of the 

 fundug varies from 6'" to V". Hence the 

 section of this cavity represented in fig. 

 426., which exhibits the organ as divided 

 from before backwards, is described by a 

 right line ; whilst the section (fig. 431.) 

 shows the cavity as bounded by three curves, 

 the degree of curvature varying in different 

 subjects, and being generally supposed to be 

 always greatest ami most marked in women 

 who have never borne children. 



This point has been much dwelt upon as 

 serving to distinguish the nulliparous from 

 the multiparous uterus. I have reason to 

 think, however, that this observation has 

 been again and again repeated without con- 

 firmation by an appeal to facts. For although 

 the sides of the virgin uterus are often strongly 

 incurved, yet in some uteri in my possession 

 from young subjects who had not borne 

 children, the walls of the cavity are nearly 

 straight, and this is the form which they have 

 in the foetus (fig. 442.), and in undeveloped 

 uteri (fig. 465.); whilst in other specimens, 

 taken from women who had borne many chil- 

 dren, the sides and fundus may be incurved in 

 various degrees. Much will depend upon the 

 mode in which the sections are made; for un- 

 less, in dividing the organ, the knife has passed 

 exactly through the median line, a portion of 

 either the anterior or posterior wall will be in- 

 cluded in the section, and the apparent form of 

 the cavity will be materially modified thereby. 



Thus the uterine cavity in the unimpreg- 

 nated state is nothing more than the narrow 

 interspace between the flattened walls which 

 are normally either in immediate contact, or 

 are separated from each other by only a small 

 quantity of mucus. The triangular form re- 

 sults from the confluence of three ducts or 

 channels ; viz., the two oviducts above, and 

 the cervical canal below. The tubal canals, 

 having passed through the substance of the 

 uterus, expand trumpet-like into the uterine 

 cavity, whilst in the same way the cervical 

 canal traced upwards is prolonged, though 

 more gradually, into the same cavity. But 

 the perpendicular diameter of the uterus 

 being always greater than the transverse, 

 the form of the cavity, in so far as it is trian- 

 gular, represents not an equilateral, but an 

 isosceles triangle with incurved sides (fig. 431 .). 



By reference to these particulars regarding 

 the form of the interspace between the uterine 

 walls, we are enabled to explain many pheno- 

 mena relating to the first entrance of the 

 ovum into the uterus, and its mode of deten- 

 tion there, before it has become organically 

 united to the uterine walls. 



The cavity of the uterus is lined by a mu- 

 cous membrane, the peculiarities of which 

 will be afterwards more fully described. This 

 membrane appears to the unaided eye nearly 

 smooth, and is usually of a pale pink colour, 

 except in those cases where death has oc- 

 curred during menstruation, when it is of a 



deep red hue, and more or less plainly 

 vascular. A moderate amplifying power, 

 however, suffices to show that the mucous 

 membrane is not smooth, but is perforated 

 everywhere by minute apertures, which are 

 the orifices of numerous ramified canals or 

 follicles occupying the substance of the mu- 

 cous membrane, and lying for the most part 

 in a direction perpendicular to the surface 

 upon which they terminate. A few folds are 

 occasionally perceptible in the mucous mem- 

 brane, these being seen chiefly in the neigh- 

 bourhood of the tubal orifices. 



The apertures by which the Fallopian 

 tubes enter the upper angles of the uterus are 

 so small as only to admit of the passage of a fine 

 bristle (fig. 406.). That by which the cavity 

 of the body communicates at its inferior angle 

 with the canal of the cervix has an average 

 diameter of 1%"%". This orifice is the 

 os uteri internum (fig. 431. i). 



The following are the dimensions of the ute- 

 rine cavity : length 11'" 12'"; breadth be- 

 tween the points of entrance of the Fallopian 

 tubes 11'" 12'"; at the centre of the ca- 

 vity 4'" ; at the os internum !"' 3"'. 



The cavity of the cervix consists of a flat- 

 tened fusiform canal running through the 

 centre of the uterine neck. The widest por- 

 tion occurs about the middle, where the 

 canal measures transversely 3"' &" (fig. 

 431. ce), whilst towards either extremity the 

 parietes gradually approximate so as to leave 

 a narrow aperture at each end ; the superior 

 aperture being the orifice already described 

 as the os uteri internum, the dimensions of 

 which have been given; the inferior being the 

 os externum, or os tineas, which measures 

 3'" V" in transverse diameter. The antero- 

 posterior diameter of the canal at its widest 

 part is not more than !"' 2'". The en- 

 tire length of the cervical cavity is 12'" 

 13"'. 



The mucous membrane lining this cavity 

 is probably not greatly inferior in extent to 

 that of the uterine body. But on account of 

 the smaller space in which it is contained, 

 instead of forming an even layer, the mem- 

 brane is here thrown into numerous folds or 

 plicae, having intermediate furrows, often 

 traversed by lesser plicae, which extend the 

 secreting surface, and furnish a more consi- 

 derable seat for those numerous mucous 

 crypts which abound upon almost every por- 

 tion of this structure. 



The forms which the cervical folds or 

 plica!! assume are sufficiently remarkable to 

 have attracted the attention of anatomists at 

 all periods. They are, however, so variable, 

 that if twenty specimens be compared to- 

 gether, scarcely two will be found to present 

 precisely the same arrangement. On this 

 account it is difficult to furnish any descrip- 

 tion of them which shall be universally appli- 

 cable. 



Nevertheless, two forms appear to me to be 

 more prevalent than others. In one a single 

 prominent raphe occupies the centre of each 

 wall of the cervix. (Fig. 431. c c.) Com- 



