PELVIS MINOR 491 



The superior surface, which is in relation, in the male, 

 with coils of small intestine and pelvic colon, is overhung 

 posteriorly by the uterus in the female, and is in relation with 

 small intestine or a coil of the pelvic colon only in the 

 anterior part of its extent. The fundus of the urinary bladder, 

 which, in the male, is in relation with the deferent ducts and 

 the seminal vesicles, is closely bound, in the female, to the 

 anterior surface of the neck of the uterus and to the upper 

 part of the anterior wall of the vagina (Fig. 220). 



Peritoneal Relations. The peritoneal relations of the 

 urinary bladder are the same in the female as in the male 

 (see p. 445). The alterations in the peritoneal relations 

 which occur as the bladder distends are the same in both 

 sexes (see p. 446). 



Changes in the form of the Bladder. The changes which 

 occur in the form of the bladder as it passes from the 

 empty to the distended condition are the same in the female 

 as in the male (see p. 443). 



Urethra Muliebris (Female Urethra). The urethra is the 

 canal by which the urine leaves the bladder. Its length is 

 about 38 mm. (one and a half inches). It takes a slightly 

 curved course from the neck of the bladder downwards and 

 forwards to the vestibule, where it opens on the surface by 

 an aperture called the orificium urethrce externum. The 

 orifice usually presents the appearance of a vertical slit, 

 and lies immediately in front of a prominent projection of 

 the mucous membrane at the lower extremity of the anterior 

 vaginal wall. The projection is easily felt, and when the 

 finger is passed over the vestibular area the position of the 

 external orifice is readily localised. On its way to the 

 surface the urethra passes through the two fasciae of the 

 urogenital diaphragm, and in the interval between them it 

 is surrounded by the fibres of the sphincter urethrse mem- 

 branaceae muscle. In the whole of its length it is closely 

 bound to the anterior wall of the vagina, and its walls are in 

 close apposition, except when the passage is opened by the 

 flow of urine through it. 



The urethra, should be split open longitudinally so that 

 its coats can be examined. They are (i) a muscular coat; 

 (2) a submucous coat; (3) a mucous coat The muscular 

 coat consists of an outer layer of circular and an inner layer 

 of longitudinal fibres. The circular fibres are strongly 



