The Pelvis. 275 



parts, a fundus or body and a cervix, by a constriction 

 the isthmus. This isthmus is a weak part, since, it is here 

 that flexions usually occur. In the virgin the isthmus is 

 midway between the cervix and the fundus, whereas, in 

 women who have borne children, it is near the junc- 

 tion of the lower and middle thirds of the organ. The 

 anterior surface of the uterus is almost flat and is covered 

 by peritoneum, which is reflected on to the bladder at the 

 level of the isthmus. The posterior surface is convex and 

 is entirely covered by peritoneum, while the lateral bor- 

 ders have attached to them the broad ligaments formed of 

 peritoneum. In the nullipara, the uterus averages about 

 three inches in length and about one and a half inches in 

 width, but in women who have borne children it is about 

 one-fifth larger. Its direction coincides with the long 

 axis of the body, although it may be inclined forwards 

 15 or 20 P when the bladder is empty, or displaced to the 

 right when the rectum is full. The cavity of the body is 

 triangular in shape and communicates with the Fallopian 

 tubes, at each superior angle, and with the cavity of the 

 neck, below. The latter cavity i.e., of the neck, termin- 

 ates in the os internum above and in the os externum below, 

 and presents a median ridge on each wall, which, with 

 lateral branches, constitute the arbor vitse. Structure. 

 The uterus is formed by three layers of muscular tissue, 

 viz., the external longitudinal, the middle circular, and the 

 internal longitudinal, while the mucous membrane is pale, 

 smooth and is pierced by innumerable tubular glands, and 

 is lined with ciliated epithelium, the motion of which is 

 directed from within outwards. The broad ligament is 

 composed of peritoneum which is hung, as it were, over a 

 cord the Fallopian tube and reaches from the sides of 

 the pelvis to the cornu of the uterus. This arrangement 

 of the peritoneum, i.e., the broad ligament, forms a parti- 



