372 THE GENITO-URINARY SYSTEM 



the sacral segments, the rest of the bladder is supplied from 

 the lower thoracic and upper lumbar segments of the spinal 

 medulla. For example, when the bladder becomes greatly 

 distended, the internal trigone is little affected^ but {the other 



[Photo by Alinari. 

 FIG. 130. The Nerve-supply of the Anterior Aspect of the Trunk. 



parts of the viscus become more or less stretched. This con- 

 dition gives rise to referred pain, which is experienced over the 

 lower part of the anterior abdominal wall, /.<?., in the areas 

 supplied by the terminal branches of the anterior rami 

 (primary divisions) of the eleventh and twelfth thoracic and 



