PELVIS 641 



wards until it lies in the same line as the vagina. When the 

 uterus attains the last-mentioned position it is said to be 

 retroverted. As it becomes retroverted the coils of intestine 

 are displaced from the recto -vaginal excavation, and the 

 uterus is forced into intimate relation with the rectum. 

 When the rectum becomes distended the uterus is pushed 

 forwards and usually to the right side. 



Dissection. When the examination of the relations of the uterus is con- 

 cluded, the dissector should cut through the rectum in the median plane. 

 Then, with the saw, he should divide the sacrum and coccyx also in the 

 median plane, and when this has been done he should cut through all 

 the remaining tissues in the same plane and separate the two halves of 

 the pelvis. All the remaining stages of the dissection and examination can 

 be carried out on each half separately. 



Vagina. The vagina is the passage which leads from 

 the uterus to the vulva. In length it is about three inches, 

 and it is widest at its upper end. Its distensibility is very 

 great, to allow the passage of the child during parturition. 

 The direction of the canal, when the bladder and rectum are 

 empty, is from above downwards and forwards, parallel with 

 the plane of the pelvic brim, so that it forms with the uterus 

 an angle which is open towards the symphysis. Its anterior 

 and posterior walls are closely applied, and in section, there- 

 fore, its cavity appears either as a transverse or as a longi- 

 tudinal slit according to the direction in which it is divided 

 (Figs. 244 and 245). 



At its upper end the vagina is attached round the neck 

 of the uterus, upon which it ascends farther posteriorly 

 than anteriorly, so that the uterus appears to pierce the 

 anterior wall of the vagina. The shallow sulcus at the upper 

 end of the vagina, round the neck of the uterus, is known as 

 the fornix of the vagina. It is formed by the reflection of 

 the mucous membrane of the vagina on to the neck of the 

 uterus, and is separated into anterior, posterior, and lateral 

 parts. The dissector should examine carefully the relations 

 of the fornices. The anterior fornix is in relation with the 

 fundus of the bladder. The posterior fornix is in relation with 

 the recto-vaginal excavation of peritoneum, and therefore an 

 injury of the vagina in this region may open into the lower 

 part of the peritoneal cavity. Each lateral fornix lies below 

 the lower medial angle of the broad ligament, and is in close 

 relation with the ureter, the uterine artery, and the mass of 

 VOL. i 41 



