3 68 



THE GENITO-URINARY SYSTEM 



superior and infero-lateral surfaces are becoming increased in 

 size. It is in conformity with this fact to find that the mucous 

 coat on the internal aspect of the posterior surface is smooth 

 and unfolded, even when the bladder is empty. This area, 

 sometimes termed the internal trigone, differs from the rest of 



Peritoneum U 



I 



, I 



Anal canal Rectum 



FIG. 128. Median Sagittal Section through Male Pelvis, showing the 

 disposition of the peritoneum when the bladder is distended. 



the bladder not only in the arrangement of its mucous coat, 

 but also in its nerve-supply (vide infra). 



It is frequently important to determine whether epithelial 

 cells in urinary deposits are derived from the renal tubules or 

 from the urinary passages. Renal epithelial cells are usually 

 cubical or spherical in shape, whereas the cells from the 

 bladder are flat, and they may be round or polygonal in out- 



