76 



HEALTH AND DISEASE 



ing into its anterior extremity for about i^ inch is the neck of the 

 uterus. The vaginal passage is lined by pale-red mucous membrane thrown 

 into longitudinal ridges extending along its whole length. Outside the 

 mucous membrane is a plentiful areolar tissue in which are large venous 

 plexuses and layers of unstriated muscle fibre; outside this again are 

 muscular layers, longitudinal and circular, continuous with those of the 

 uterus. Beneath the vagina are the urethra and the bladder (k, fig. 228), 

 and above it the rectum (a, fig. 228). 



UtePUS (fig. 230). — This is the organ which receives the ovum and in 



Fig. 230.— Uteri with Slioit and Long Necks 



which the foetus is developed. It is composed of a neck and a body, which 

 divides into two horns of approximately equal size. 



The neck is embraced by the anterior extremity of the vagina, into 

 which it projects after the manner of the end of a tap into a barrel; it 

 is rounded in outline though somewhat compressed from above down- 

 wards. The opening of the neck into the vagina is called the "os uteri 

 externum". The opposite extremity opens into the body of the organ, 

 and is the " os uteri internum". The body of the uterus is about 8 to 

 10 inches in length, and is situated partly within the pelvis and partly 

 in the abdomen, having the rectum above and the bladder below. The 

 horns are about 8 inches in length, and hang suspended by two broad 

 ligaments from the lumbar portion of the spine. They are somewhat 

 laterally compressed, are concave on their upper surface and convex on 

 the lower. The anterior extremity is obtusely pointed, and receives the 



