984 



FEMALE ORGANS OF GENERATION. 



from its vaginal attachment, is lower in position, and, when the tube is 

 closed, rests on the posterior wall of the vagina. These borders or lips are 

 generally smooth, but, after parturition, they frequently become irregular, 

 and are sometimes fissured or cleft. 



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Fig. 685. POSTERIOR VIEW OF THE UTERUS AND ITS APPENDAGES. 



The cavity of the uterus has been opened by the removal of the posterior wall, and the 

 upper part of the vagina has been laid open ; a, fundus ; b, body ; c, cervix ; d, on the 

 anterior lip of the os uteri externuin ; e, the interior of the vagina ; /, section of the 

 walls of the uterus ; i, opening of the Fallopian tube ; o, ovary ; p, ligament of the 

 ovary ; ?, broad ligament ; s, Fallopian tube ; t, its fimbriated extremity. 



Owing to the great thickness of its walls, the cavity of the uterus is very 

 small in proportion to the size of the organ. The part within the body of 

 the organ is triangular, and flattened from before backwards, so that its 

 anterior and posterior walls touch each other. The base of the triangle is 

 directed upwards, and is curvilinear, the convexity being turned towards the 

 interior of the uterus. This form is owing to the prolongation of the cavity 

 through the substance of the organ towards its two superior angles, where 

 two minute foramina lead into the Fallopian tubes. At the point where the 

 body is continuous below with the neck, the cavity is slightly constricted, 

 and thus forms what is sometimes named the internal orifice (os uteri inter- 

 num t isthmus vel ostium uteri) ; it is often smaller than the os externuin, 

 and is a circular opening. That portion of the cavity which is within 

 the neck, resembles a tube slightly flattened before and behind ; it is some- 

 what dilated in the middle, and opens inferiorly into the vagina by the os 

 tincse. Its inner surface is marked by two longitudinal ridges or columns, 

 which run, one on the anterior, the other on the posterior wall, and from 

 both of which rugse are directed obliquely upwards on each side, so as to 

 present an appearance which has been named arbor vitce uterinus, also palmce 

 plicatca : this structure is most strongly marked anteriorly. 



Structure. The walls of the uterus consist of an external serous cover- 

 ing, an internal mucous membrane, and an intermediate proper tissue. The 

 peritoneal layer covers the fundus and body, except at the sides and for 

 about half an inch of the lower part of the body in front, which is attached 

 to the base of the bladder. 



The proper tissue of the uterus constitutes much the greater part of 

 its walls, which are thickest opposite the middle of the body and fundus, 



