408 



The Bladder 



wards, lest, as I have seen happen, it descend in the cellular interval 

 behind the pubes, and fail to enter the bladder. 



In a fat subject the trocar may be introduced where the linea alba 

 is crossed, a few inches above the pubes, by the transverse crease. 



The muscular coat consists of non-striated longitudinal fibres 

 chiefly at the front and back ; some of them are connected with the 

 prostate and also with the true ligaments ; chiefly towards the neck of the 

 bladder circular bands exist ; they are associated with the prostate and 

 form a kind of sphincter. When long-continued and extra work is 



thrown upon the muscular 

 coat, as in the case of 

 old stricture, hypertrophy 

 results ; and sometimes a 

 pouch of the mucous 

 lining is forced through 

 a gap between the 

 thick muscular bands 

 and forms a herniated sac 

 in which a stone may be 

 lodged. Should a calculus 

 fall into such a sac, there 

 would be a sudden cessa- 

 tion of symptoms, and the 

 surgeon might thence- 

 forth fail to strike it. In 

 such cases examination by 

 the rectum should give 

 valuable assistance ; and 

 the stone might be suc- 

 cessfully removed by a 



Stricture at bulb ; membranous urethra dilated ; bladder cnnra nnhir r>rpratinn 

 thickened, and mucous membrane roughened. SUpra-pUblC Operation. 



A definite band of 



muscular fibres extends between the two ureters the inter-uretal band 

 and in cases of old-standing urinary obstruction it is recognised after 

 death as a prominent ridge bounding the front of a deep depression of 

 the mucous membrane. 



The mucous coat, which is attached to the muscular by a layer of 

 connective tissue, is thrown into rugas which are effaced as the 

 bladder fills. But in the triangular part of the floor which intervenes 

 between the openings of the ureters and the beginning of the urethra 

 there are no rugae, the mucous coat being smoothly spread. This 

 area is called the trigone ; against it the stone is forcibly and pain- 

 fully driven during micturition. In certain conditions the mucous 

 coat is thrown into firm, permanent ridges, which, when the urine is 

 alkaline, may become encrusted with phosphates. The epithelium is 

 of a modified squamous type. 



