1366 



THE URINO GENITAL ORGANS 



which exist, especially near the neck of the bladder, have been regarded as such. The epithelial 

 'ells rest upon a basement membrane, beneath which is the fibroelastic tunica propria, which con- 

 tains diffuse lymphoid tissue, and in which solitary follicles have been found. 



RIDGE FORMED BY 

 * INTERURETERAL 

 MUSCLE 



FIG. 1117. The interior of the bladder, showing the vesical trigone. (Poirier and Charpy.) 



The Interior of the Bladder. Upon the inner surface of the bladder are seen 

 the mucous membrane, orifices of the ureters, the trigone, and the commencement 

 of the urethra. 



LONGITUDINAL 

 FIBRES 



FIG. 1118. -The internal surface of the bladder. (Poirier and Charpy.) 



The mucous membrane of the empty bladder is thrown into folds or rugae, except 

 over the trigone, where it is firmly adherent to the muscular coat and is smooth 

 (Figs. 1117 and 1118). The folds disappear when the bladder is distended.. 



