AXATOMY OF THE UTERUS. 421 



The body (a) of the uterus is more convex posteriorly than ante- body; 

 riorly, and decreases in size down to the neck. It is covered on 

 both aspects by the peritoneum, except at the lower part in front 

 (about half an inch), where it is connected to the* bladder. To parts 

 each side the parts contained in the broad fold of the peritoneum J^eJ 511 * 

 are attached (p. 391), viz., the Fallopian tube at the top, the 

 round ligament rather below and before the last, and the ovary 

 and its ligament below and behind the others. 



Dissection. To examine the interior of the uterus, a cut is to Open the 

 be made along the front from the fundus to the external os uteri ; uterus - 

 and then some of the thick wall is to be removed on each side of 

 the middle line to show the contained cavity (fig. 156). 



The thickness of the uterine wall is greatest opposite the middle its thick- 

 of the body. It is greater at the centre than at the extremities of ness- 

 the fundus, the wall becoming thinner towards the attachment of the 

 Fallopian tubes. 



Interior of the uterus. Within the uterus is a small space, in the 

 which is divided artificially into two that of the body, and that m 

 of the neck. 



The space occupying the body of the viscus (c) is triangular in j^J^j*^ 

 form, and compressed from before backwards. Its base is at the FU the body, 

 fundus, where it is convex towards the cavity, and the angles are 

 prolonged into the Fallopian tubes. The apex is directed down- which is 



i .LI *. j.i i if 1-1 narrowed 



wards, and joins the cavity in the neck by a narrowed circular below; 

 part, or isthmus (os uteri intemum) which may be narrower than 

 the opening of the uterus into the vagina. 



The space within the neck (d) terminates below at the external os and a 

 uteri, and is continuous above with the cavity within the body. It is s 

 larger at the middle than at either end, being spindle-shaped, and 

 is somewhat flattened like the cavity of the body. Along both the 

 anterior and the posterior wall is a longitudinal ridge ; and other 

 ridges (rugce) are directed obliquely from these on each side : this 

 appearance has been named arbor vitce uterinus. In the intervals in the neck 

 between the rugae are mucous follicles, which sometimes become ^0 vftse 



distended with fluid, and give rise to rounded clear sacs. 



STRUCTURE. The dense wall of the uterus is composed of layers uterus is a 

 of unstriated muscular fibre, intermixed with areolar and elastic 

 tissues and large blood-vessels. On the exterior is the peritoneum ; 

 and lining the interior is a thin mucous membrane. 



The muscular fibres can be demonstrated at the full period of There are 



J . three strata, 



gestation to form three strata m the wall of the uterus, viz., 

 external, internal, and middle : 



The external layer contains fibres which are mostly transverse ; external, 

 but at the fundus and sides they are oblique, and are more marked 

 than along the middle of the organ. At the sides the fibres con- 

 verge towards the broad ligament ; some are inserted into the 

 subperitoneal fibrous tissue ; and others are continued into the 

 Fallopian tube, the round ligament, and the ligament of the ovary. 



The internal fibres describe circles round the openings of the internal, 

 Fallopian tubes, and spread from these apertures till they meet at 



