430 



MANUAL OF HISTOLOGY. 



fibres being also furnished with ganglion cells. Their mode of 

 termination in the muscular layer is not definitely known, but 

 may be assumed to resemble that of ordinary smooth muscu- 

 lar-tissue. 



THE BLADDER 



has the same type of structure as the ureters, but contains, in 

 addition, a serous covering in its upper portion. The different 

 coats of the bladder are, however, much thicker than the cor- 

 responding layers in the other urinary excretory passages. 



Th^ epithelial lining of the mucous membrane shows the 

 three varieties of its cellular elements in a clearly defined man- 

 ner. 



The connective-tissue stratum presents 110 noteworthy pe- 

 culiarities, if we ex- 

 cept the comparative 

 abundance of simple 

 acinous glands. 



The bundles of 

 muscle -cells in the 

 muscular-coat inter- 

 lace, forming irregu- 

 lar, long-stretched 

 meshes. This irregu- 

 lar arrangement pre- 

 vents the distinct rec- 

 ognition of successive 

 , a ceii of the layers, each with a 

 largely prevailing di- 

 rection. Nevertheless, 



we find in the external portion of the muscle-coat some pre- 

 dominance of longitudinal bundles, together with an abundant 

 supply of elastic fibres. The anterior wall and vertex of the 

 bladder show this arrangement very conspicuously, in fact the 

 muscle-fibres have here received a separate name, that of detru- 

 sorurince. The vesical neck shows a tolerably distinct thicken- 

 ing of its circular muscle-fibres, which is known as the sphincter 

 vesicce. It should always be borne in mind that the arrange- 

 ment of the muscular coat is apt to vary in different individuals, 

 the description here given will, however, be found to apply to 

 the majority of cases. 



FIG. 182. Epithelium of the urinary bladder, 

 second layer ; ft, a cell of the first layer ; c, shows the first, second, 

 and third layers of the epithelium in connection. Obersteiner. 



