THE URINARY BLADDER 



I ['. 



and renal pelvis. It is therefore impossible to determine from which 

 of these portions detached epithelial cells are derived when found by 

 microscopical examination of the urine. Epithelium may become de- 



FIG. 413. TRANSECTION OF THE WALL OF A CHILD'S BLADDKK. 

 a, mucosa; b, muscular coat; c, serous coat. HemaU'in and rosin. Photo. 



tached from any portion of the excretory passn^-s, and as a n-sult of 

 inflammatory changes not only the superficial cells but also the deeper 

 pear-shaped cells may be desquamated. 



The character of the epithelium varies with the collapse and dis- 

 tention of the organ. When empty the mucous membrane is thrown 



