112 THE URINARY ORGANS. 
Croupous inflammation of the bladder. 
Tubercular cystitis. 
What are the changes in an acute cystitis ? 
The mucous membrane is congested and swollen, and there isa 
desquamation of the lining epithelium, sometimes with a formation of 
superficial or deep ulcers. The changes may be so slight as not to be 
evident after death. 
What changes occur in chronic cystitis ? 
The mucous membrane is swollen and gray in color, or it may be 
mottled with spots of congestion. The membrane may be infiltrated 
with pus, and thickened either diffusely or in the form of tufts or 
polypi; sometimes it becomes atrophied. The epithelial cells covering 
the inner wall become cast off, especially on the more prominent points, 
and deep ulcers may be formed. Sometimes the muscular coats be- 
come paralyzed. The inflammatory process at times assumes a more 
necrotic character. There may be a necrosis implicating all the coats 
of the bladder, producing perforation. In some cases all the different 
layers of the bladderwall may become infiltrated with pus. producing 
abscesses which may open internally or externally. 
Describe croupous inflammation of the bladder. 
The inner surface of the bladderwall may become coated with a 
layer of fibrin, in which are entangled pus and epithelial cells. The 
fibrin may infiltrate the mucous membrane separating the cells of 
which it is composed. This form of inflammation may occur with 
either of the preceding forms. 
How does tubercular inflammation affect the bladder ? 
It begins as miliary tubercles in the bladderwall. These tubercles 
breaking down form ulcers. 
What tumors have been found in the bladder ? 
Fibromata and carcinomata. 
What are vesical calculi ? 
They are concretions found in the bladder, and range in size from a 
mustard seed to masses four or five inches in diameter. They are of 
different shapes and may be smooth or rough. Their most common 
constituents are phosphates, urates, uric acid and oxalate of calcium. 
To what may changes in the size of the urethra be due? 
There may be dilatation caused by obstruction from stricture or by 
impaction of a calculus or foreign body. The calibre of the urethra 
