UTERUS (NORMAL ANATOMY). 



627 



the substance of the organ. No just concep- 

 tion, however, of the real form or capacity of 

 this interspace can be obtained by examining 

 it with the aid of sections made in one direc- 

 tion only. 



In order to obtain a correct notion of the 

 form and extent of this cavity, it is desirable 

 first to make a longitudinal section through 

 the centre of the entire organ parallel with 

 its lateral borders. The cavity or interspace 

 is then indicated by a line running from below 

 upwards, and terminating within half an inch 

 of the funclus (fig. 426.). 



The upper half of this line indicates the 

 cavity of the uterus ; the lower half, that of 

 the cervix. The latter alone exhibits a true 

 cavity; for here the parietes of the cervix are 



Fig. 427. 



Fig. 2$. 



Fig. 429. 



Fig. 430. 



Series of horizontal sections of the uterus. 



Fig. 427., just above the entrance of the Fallopian 

 tubes, fig. 428., in the centre of the cavity. Fig. 

 429., close to the internal os uteri. Fig. 430., the 

 centre of the cervical canal. The upper or more 

 convex border marks the posterior surface in each 

 section. (Ad Nat.) 



observed to diverge slightly, so as to leave a 

 spindle-shaped canal traversing the whole 

 length of the uterine neck (J!g. 431. cc). 



A second view is obtained by cutting com- 

 pletely through the uterus in the direction of 

 its transverse diameter, and parallel with its 

 extremities. If the entire organ be cut up into 

 many such segments (j%.427 430.), itis then 

 seen, from the length of the central line, that 

 the cavity varies in breadth, its widest part 

 being in the segment which includes the ex- 

 tremities of the Fallopian tubes ; whilst from 

 this point downwards the line diminishes in 

 length, until at the narrowest portion of the 

 uterus, or that representing the commence- 

 ment of the cervix, it measures only !'" 

 3'" in diameter. 



But the most complete view of the interior 

 of the uterus is obtained by a section carried 

 through the centre of the organ, dividing it 

 midway between its anterior and posterior 

 walls. The entire cavity which is thus ex- 

 hibited at one view is seen to be of a trian- 

 gular form ; its boundaries being formed 

 superiorly by the fundus, and on either side 

 by the two lateral borders, whilst in each 

 angle is observed an aperture. The two su- 

 perior openings are the lower orifices of the 

 Fallopian tubes. The inferior opening lead- 

 ing to the cervical canal constitutes the os 

 uteri internum (fig. 431. i). 



Fig. 431. 



Vertical section of nulliparous uterus parallel with 

 its anterior and posterior walls. 



c, uterine cavity; cc, cervical cavity or canal; 

 i, internal os uteri ; e, external os uteri ;f,f, Fallopian 

 tubes ; v a, vagina, (Ad Nat.) 



Since the cavity in the interior of the 

 uterine body has a triangular form, whilst 

 externally the shape of the organ is more or 

 less pyriform, it is evident that the parietes of 

 this " hollow muscle " cannot have every- 

 where an equal thickness, for otherwise the 

 form of the cavity would correspond with 

 s s 2 



