THE URINARY ORGANS. 



649 



Rupture of the bladder may be produced by severe blows and falls 

 when the bladder contains urine. More rarely rupture takes place from 

 overdistention. Death may occur from rupture of the bladder with 

 escape of urine into the peritoneal cavity, without evidences of perito- 

 nitis. 



Perforations of the bladder may be due to ulceration and gangrene, 

 to abscesses from without, and to cancerous ulce ration from the ad join - 



FIG. 411. DIVERTICULA OF THE BLADDER. 



ing organs. Fractures of the pelvic bones may be accompanied by lacera- 

 tion of the bladder. Perforations of the bladder may lead to the estab- 

 lishment of fistulae, communicating with the rectum, vagina, uterus, or 

 opening externally. 



DISTURBANCES OF CIRCULATION. 



Hyperaemia. Aside from active hyperaemia of the mucous membrane 

 in acute inflammation, the bladder is not infrequently the seat of chronic 

 congestion from obstruction to the venous circulation. Under these con- 

 ditions there may be chronic catarrhal inflammation, or a marked dilata 

 tion of the veins (vesical haemorrhoids), which may gfve rise to haemor- 

 rhage or to obstruction of the opening of the ureters. 



Haemorrhage. Extensive haemorrhages into the bladder are eommonly 

 due to injury or to the presence of calculi or tumors. Small hemor- 

 rhages into the substance of the mucous membrane may accompany in- 

 flammation, the haemorrhagic diathesis, scurvy, purpura, smallpox, etc. 

 If the haemorrhage is considerable and occurs rapidly in an empty blad- 

 der, a clot is apt to form ; but when the blood mixes with urine as it is 

 extravasated it more commonly remains liquid and is discharged as a 

 reddish-brown fluid. - * 



