HYPEETEOPHY OF THE BLADDEE. 433 



The pain in acute cystitis is felt in the supra-pubic region 

 from the position of the bladder behind the symphysis in the 

 pelvis, but it is also referred to the end of the penis and to the 

 perineum, owing to the common nerve supply from the fourth 

 sacral. 



Hypertrophy of the Bladder. Hypertrophy of the muscular 

 coat of the bladder is, as a rule, the outcome of obstruction to 

 the passage of urine through the urethra. When it occurs the 

 detrusor urinse exhibits considerable enlargement of its fibres, so 

 as to produce distinct fasiculation. The firm, projecting ridges 

 of hypertrophied muscular fibres may often be felt by a sound 

 introduced into the bladder, and may even be mistaken for 

 calculi or growths. 



The mucous membrane between these fasiculi of muscular 

 tissue is apt to bulge, from the pressure caused by the retained 

 urine, which bulging amounts in many cases to an actual hernia 

 of the membrane. Such protrusions are known as sacculi, and 

 they may occur at those parts of the bladder uncovered or 

 covered by peritoneum. If they attain a fair size, and particu- 

 larly if the entrance into them becomes narrowed, urine is apt 

 to stagnate within them, and calculi may be formed. In other 

 cases a sacculus may give way under pressure, and urinary 

 extravasation occur, possibly into the peritoneal cavity, or into 

 the cellular tissue of the pelvis or into that lying behind the 

 anterior abdominal wall, the so-called cavity of Eetzius. 



Distension of the Bladder. The empty bladder lies entirely 

 below the brim of the true pelvis, but when it becomes distended 

 it rises up into the abdomen, and may then reach as high as 

 the umbilicus. During this distension the reflection of the 

 peritoneum from its anterior surface by the urachus and the 

 obliterated hypogastric arteries is carried somewhat upwards, 

 and an interval is left between the level of the symphysis pubis 

 and the peritoneum, through which the organ can be tapped or 

 suprapubic cystotomy performed, without the peritoneal cavity 

 being traversed. In childhood the bladder is almost entirely out 

 of the pelvis proper. 



C.A.A. 28 



