1250 



UROGENITAL SYSTEM 



Form. — When distended it assumes in the male an ovoid shape with its 

 longest diameter directed from above downward and backward; but in the female 

 the transverse diameter is the greatest, in accordance with the greater breadth 

 of the pelvic cavity. In the child it is somewhat pear-shaped, the stalk being 

 represented by the urachus. 



Parts. — ^For convenience in description five surfaces may be recognized, but 

 they are but indistinctly separated from each other. One, the anterior or pubic 

 surface, is directed forward and downward; second, the superior or intestinal 

 surface, looks upward; the third, the posterior surface, looks backward; and the 

 other two are the lateral surfaces. The anterior, superior, and lateral surfaces 

 meet at the vertex of the bladder, from which the middle umbilical ligament 

 (urachus) extends to the umbilicus; the posterior surface, sometimes flat and some- 

 times, especially in old age, convex, forms what is known as the base or fundus 

 [fundus vesicae] ; and the portion of the viscus intervening between the vertex and 



Fig. 1013. — Median Sagittal Section of the Male Pelvis. 

 (From a preparation in the Museum of St Thomas's Hospital ) 



Transverse 

 colon 



Small I 

 intes- 

 tine 



Coccyx 



Recto- 

 vesical pouch 

 with adipose 

 fold 



Rectum 



Ext sphincter am 



fundus is termefl the body [corpus vesica)]. In the centre of the line between 

 the anterior and posterior surfaces is the internal urethral orifice [orificium urethra? 

 internum], by whicli the bladder communicates with the urethra, and the portion 

 of the organ immediately surrounding this is sometimes spoken of as the neck. 



When the bladder is empty and relaxed, the superior surface sinks down upon 

 the anterior and posterior surfaces, thus becoming concave, and the cavity of the 

 organ is reduced to a T- or Y-shaped fissure. In the female, the cavity of the 

 empty bladder in mid-sagittal section often more nearly resembles a figure 7 (see 

 fig. 1014). 



Relations. — -The anterior surface looks downward and forward toward the 

 symphysis pubis (figs. 1013, 1014). It is uncovered by jjeritoneum, but is sepa- 

 rated from th(! i)ubi(; );ones and anterior attachments of the obturatores interni 

 and the levatores ani by a space known as the prevesical space (cavum Retzii), 



