434 CLINICAL APPLIED ANATOMY. 



Rupture of the Bladder. Laceration or rupture of the bladder 

 may be caused by traumatism or over-distension. Gun-shot 

 injuries, fractures of the pelvis, rough usage of instruments, 

 particularly sounds or lithotrites, may all cause perforation of 

 the undistended or only slightly filled organ. External violence 

 such as a kick or blow, coming upon the distended viscus, with- 

 out the intervention of the protection of the contracted recti 

 abdominis, may induce a rupture of that part of the bladder wall 

 which is covered by peritoneum. Further, it is possible, though 

 not common, for over-distension to spontaneously cause a giving 

 way of the vesical wall, either where covered or uncovered by 

 peritoneum, and this is particularly liable to happen in those 

 cases where the distension occurs in a hypertrophied and sac- 

 culated bladder. 



When the rupture is into the peritoneal cavity and sterile 

 water is injected into the bladder, this will find its way through 

 the rent into the larger space beyond. Hence it follows that if 

 a measured quantity is introduced, only a portion of this will be 

 withdrawn, thus establishing the fact of the perforation of the 

 vesical wall. 



Retention of Urine. Eetention of urine within the bladder 

 is caused by complete obstruction to its outflow along the 

 urethra, and is therefore due to pressure from without, disease 

 in the walls of the tube itself, or blockage from within. 



One of the commonest causes of complete retention is organic 

 stricture of the urethra, the anatomical connections of which 

 are discussed later. Enlargement of the prostate gland is also 

 a not uncommon factor in producing retention, and is also sub- 

 sequently dealt with. Here the obstruction of the urethral 

 passage by a calculus may be alluded to. 



Particularly in children, a calculus which is either formed in 

 the bladder or passed down the ureter from the kidney, is flushed 

 out by the flow of urine from the bladder into the urethra, and, 

 as a rule, is arrested in the narrowest part of that tube, that is to 

 say, just within the lips of the external meatus. In order to 

 extract the impacted stone it is well to remember that since 



