THE URINARY ORGANS. 



vertical section, is Y-shaped, the urethra forming the stem of the Y. It is placed 

 deeply in the pelvis, flattened from before backward, the anterior limb of the Y 

 reaching as high as the upper border of the symphysis pubis. When slightly dis- 

 tended it has a rounded form, and is still contained within the pelvic cavity ; and 

 when fully distended it is ovoid in shape, and rises into the abdominal cavity. When 

 greatly distended it may reach nearly as high as the umbilicus. It is larger in its 

 vertical diameter than from side to side, and its long axis is directed from above 

 obliquely downward and backward, in a line directed from some point between the 

 os pubis and umbilicus (according to its distention) to the end of the coccyx. The 

 bladder, when distended, is slightly curved forward toward the anterior wall of 

 the abdomen, so as to be more convex behind than in front. In the female 

 it is larger in the transverse than in the vertical diameter, and its capacity is 



Preface. 



FIG. 73. Vertical section of bladder, penis, and urethra. 



said to be greater than in the male. 1 When moderately distended it contains 

 about a pint. 



The bladder has a summit and five surfaces, superior or abdominal, postero- 

 inferior .or base, antero-inferior or pubic, and two lateral or sides. 



The summit or apex of the bladder looks forward and upward ; it is connected 

 to the abdominal wall by a fibro-muscular cord, the urachus, which is the obliterated 

 remains of a tubular canal which, in the embryo, prolongs the cavity of the bladder 

 into the allantois. It passes upward from the apex of the bladder between the 

 transversalis fascia and peritoneum to the umbilicus, becoming thinner as it ascends. 

 On each side of it is placed a fibrous cord, the obliterated portion of the hypogastric 

 artery, which, passing upward from the side of the bladder, approaches the urachus 

 above its summit. In the infant, at birth, the urachus is sometimes found por- 

 1 According to Henle, the bladder is considerably smaller in the female than in the male. 



