STEUCTUEE OF THE BLADDEE. 



425 



having: varions appearances in different bladders. Their course may in 

 general be looked upon as transverse, but for the most part throughout 

 the upper two-thirds of the bladder they cross one another in very oblique 

 bands : towards the lower part of the organ tliey assume a more circular 

 course, and upon the fundus and trigone form a tolerably regular laj^er. 

 Close to and around the cervix, in iunnediate connection with the pro- 

 state in the male, they densely encircle the orifice and constitute w'hat 

 has been named the sjjldiidcr vcsiccc, which, however, is not distinct from 

 the other fibres. 



The ihird stratum of fibres, still more deeply situated, and which 

 might be termed internal longitudinal, was first described by Ellis, who 



Fir;. 307. — View of the Muscular 

 Fibres op the Bladder from the 

 LEFT Side (Allen Tliomsou, after Pett^ 

 grew). i • 



The anterior and posterior superficial 

 fibres are seen running from lielow u^j- 

 ■wards, crossing each other by their diver- 

 gence on the sides of the bladder, and are 

 indicated by the same letters as in the 

 jireceding figures ; at c, a portion of the 

 anterior longitudinal fibres has been re- 

 moved so as to expose the deeper circular 

 fibres. 



distinguished it as " submucous." 

 It is very delicate, and its fibres, 

 directed longitudinally, are dis- 

 posed in a regular manner round 

 the cavity of the bladder. 



The muscular coat of the bladder foi-ms so in-egular a covering, that, when the 

 organ is much distended, intervals arise in \A-hich the walls are very thin ; and, 

 should the internal or mucous lining protrude in any spot through the muscular 

 bundles, a sort of hernia is produced, Avhich may go on increasing, so as to form 

 what is called a vesical sacculus, or appendix rcsicce, the bladder thus affected 

 being termed .sacculated. Hypertrophy of the muscular fasciculi, which is liable 

 to occur in stricture of the m-cthra or other affections impeding the issue of the 

 urine, gives rise to that condition named the fasciculated blacfder. in which the 

 interior of the organ is marked by strong reticulated ridges or columns, with 

 intervening depressions. 



On the muscular arrangements of the bladder, see ElKs. in Trans. Med. Chir. 

 Society, 18r)(j, and Demonstrations of Anatomy ; Pettigrew, in Phil. Trans, for 

 18(56 ; Sabatier, Rech. Anat. et Phys. sur les Appareils musculaii-es correspondants 

 a la vessie et a la prostate dans les deux sexes, 1864. 



Next to the muscular coat, between it and the mucous membrane, but 

 much more intimately connected with the latter, is a well-marked layer 

 of areolar tissue, the vascular or submucous coat. This submucous 

 areolar layer contains a large quantity of very fine coiled fibres of elastic 

 tissue. 



The mucous membrane of tlie bladder is soft, smooth, and of a pale 

 ]-ose colour. It is continuous above with the lining membrane of the 

 ureters and kidneys, and below with that of the urethra. It adheres 

 loosely to the muscular tissue, and is thus liable to be throAvn into 

 wrinkles, except at the trigone, where it is always more even. It is 



