UTERUS (NORMAL ANATOMY). 



631 



be observed, this distinction in a great mea- 

 sure vanishes under the application of the 

 microscope. 



Peritoneal coat. The outer serous coat, 

 which constitutes the thinnest of the three 

 component tissues of the uterus, is formed of 

 the centre of the principal fold of the broad 

 ligament, which is closely applied to the uterine 

 body and fundus, and to a portion of its neck. 



It is of great importance to the com- 

 prehension of certain points in the pathology 

 of the uterus, to be hereafter considered, that 

 the relations of this peritoneal covering to 

 the^roper structures of the organ, as well as 

 to adjacent parts, should be accurately deter- 

 mined. The most important of these rela- 

 tions are shown in fig. 433., representing a 

 vertical section of the pelvis and its con- 

 tents. In this view the reflexions of peri- 

 toneum over the centre of the uterus are 

 shown. The membrane, after lining the 

 abdominal walls, and covering the fundus, and 

 a portion of the posterior surface of the 

 bladder, is suddenly arrested in its descent at 

 a point very nearly opposite to, but some- 

 times a little below the internal os uteri, and 

 therefore about the seat of junction of the 

 body with the neck of the uterus. Here the 

 membrane forms a sharp fold or angle, and 

 becomes immediately applied to the anterior 

 face of the uterine "body, while the cervix, 

 which lies in great part, if not entirely, below 

 this level is left uninvested. The peritoneum, 

 then, after ascending over the anterior uterine 

 wall, covers the fundus and sides of the organ, 

 and descending upon the posterior surface, it 

 remains closely adherent to the tissues be- 

 neath, until it reaches the level of the anterior 

 point of reflexion. At this point the perito- 

 neum becomes much more loosely connected 

 with the uterus by the interposition of a 

 quantity of lax connective tissue which inter- 

 venes between it and the posterior cervical 

 wall (fig. 433, G). The membrane, however, 

 still descends, covering first the posterior wall 

 of the supra-vaginal portion of the cervix, and 

 then a part of the fornix, or upper end of the 

 vagina. The extent of peritoneal covering 

 which the vagina receives, varies in different 

 subjects from half an inch to nearly an inch. 

 The membrane then, as before, turns upwards, 

 but at a more obtuse angle, to invest the rec- 

 tum, so that a pouch is formed, termed the 

 recto-vaginal or retro-uterine pouch, which 

 is sometimes of considerable size. 



The adhesion of the peritoneum to the 

 uterus is closest along the median line, and 

 over the whole of the fundus, at which points 

 its separation by dissection from the tissues 

 beneath cannot" be effected without the aid 

 of prolonged maceration ; but towards either 

 side of the organ the connection is less inti- 

 mate, so that here the membrane may be 

 made to glide to a limited extent over the 

 sub-lying structures. At the two upper 

 uterine angles the peritoneum is continued 

 on to the uterine appendages ; viz., the Fal- 

 lopian tubes, round ligaments and ligaments 

 of the ovaries. After sending off extensions 



to invest these parts, the portions of mem- 

 brane which cover the anterior and posterior 

 faces of the uterus respectively come nearly 

 into apposition along the lateral borders of 

 the organ (fig. 427.), where they are con- 

 joined by a quantity of lax fibrous tissue, 

 which serves to bind them loosely together, 

 and at the same time to give support and 

 protection to the numerous blood vessels 

 entering the uterus on either side along the 

 whole of this border. 



A similar portion of lax fibrous tissue 

 serves to connect the anterior wall of the 

 uterine cervix, where it is uncovered by peri- 

 toneum with the posterior surface of the 

 bladder, with which it lies in contact. 



The sectional views of the uterus in three 

 directions already given serve to explain the 

 whole of the relations of the outer or peri- 

 toneal coat of the uterus to the muscular or 

 proper coat. 



Fig. 426. shows the mode of attachment of 

 this membrane to the anterior and posterior 

 surface and fundus along the median line, 

 and also the parts which are left uncovered 

 by peritoneum. Commencing from the os 

 uteri the vaginal portion of the cervix forming 

 the anterior lip (a) receives an investment of 

 mucous membrane as far as its point of at- 

 tachment to the anterior wall of the vagina 

 (v a). Beyond this the whole of the remain- 

 ing portion of the anterior wall of the cervix, 

 measuring above one inch in length (bb), is 

 left uncovered either by mucous or serous 

 membrane. At the termination of this space 

 the peritoneum, reflected off from the bladder, 

 reaches the uterus, and after investing the 

 organ, is continued down to and beyond the 

 fornix of the vagina (/). But at this point 

 the mass of loose connective tissue before re- 

 ferred to separates the peritoneum from the 

 posterior cervical wall to a great extent (c), 

 while finally a much larger portion of the cer- 

 vix is contained within the vagina, posteriorly 

 than anteriorly, and is consequently covered 

 by mucous membrane(p), because the vaginal 

 walls are attached at a much higher point here 

 than anteriorly. 



Fig. 431. serves to exhibit the relations of 

 the peritoneum to the fundus, and the absence 

 of that membrane from the lateral borders of 

 the uterus, while figs. 427. 430. exhibit the 

 relative proportions of the covered and un- 

 covered parts as seen in a series of horizontal 

 sections of different portions of the organ. 



The middle or smooth-muscular coat, upon 

 which depends the remarkable firmness and 

 solidity of the uterus, constitutes the prin- 

 cipal bulk of the organ. This coat upon sec- 

 tion appears of a pale pink colour, mottled 

 with irregular white lines, and permeated by 

 vessels which are particularly numerous near its 

 lateral borders. The following are the compo- 

 nent tissues of the middle uterine coat, viz. : 



1st. Smooth-muscular fibres. These are 

 found in every portion of this coat, and con- 

 sist of fusiform fibres of the kind termed by 

 Kolliker contractile fibre-cells, in which a 

 single elongated oval nucleus may be occa- 

 s s 4 



