BLADDER, NORMAL ANATOMY. 



383 



affecting the sac itself; hence a process of this 

 sort may enlarge indefinitely, and has been 

 known in some cases to have formed a part of 

 the contents of an inguinal hernia. Pouches of 

 this nature, for there may be several in the 

 same individual, sometimes contain calculi, the 

 latter having probably been the cause of the 

 former, inasmuch as the muscular coat having 

 been excited by the irritation of the stone to 

 increased action, has forcibly pressed the latter 

 into one of the cells of the mucous membrane, 

 which has then become enlarged and protruded, 

 so as to contain the calculus impacted in it. 

 The consequence of this occurrence to the indi- 

 vidual, however, is often a fortunate remission 

 of suffering, because the stone being now fixed 

 in a cell, ceases to excite pain or irritation : it is 

 by occurrences of this nature that the boasted 

 and sometimes fortunate efficacy of certain 

 lithontriptic medicines as cures for stone is to 

 be explained. 



The exact arrangement of the muscular fibres 

 at the neck of the bladder has not been very 

 accurately explained ; some describe them as 

 arranged circularly so as to constitute a true 

 sphincter: this opinion is maintained by John 

 Bell, System of Anatomy, vol. iv. p. 159 ; also 

 by Palfin, Anat. torn. i. p. 163; by Meckel, 

 Anat. vol. iii. p. 564 ; by Bayle and others. 

 Sir Charles Bell also describes a sphincter 

 vesica? to exist, but. places it in a different situa- 

 tion from that usually assigned. His description 

 of this muscle is as follows : " to exhibit it, cut 

 off all the appendages to the bladder except 

 the prostate gland, make an incision into the 

 fundus and invert it, dissect off the inner mem- 

 brane from around the orifice of the urethra ; 

 a set of fibres will be discovered on the lower 

 half of the orifice running in a semicircular 

 form round the urethra ; these make a band of 

 about half an inch in breadth, particularly 

 strong on the lower part of the opening, and 

 having mounted a little above the orifice on 

 each side, they disperse a portion of their fibres 

 in the substance of the bladder; a smaller and 

 weaker set will be seen to complete their course 

 surrounding the orifice on the upper part, to 

 these sphincter fibres a bridle is joined which 

 conies from the union of the muscles of the 

 ureters; this is the most posterior part of all 

 the muscles which embrace the urethra, it re- 

 sembles the sphincters of the other hollow vis- 

 cera; for example, that of the pyloricorificeof the 

 stomach.''* The great advantage of the sphincter 

 as thus described must be, as Sir C.Bell says, 

 to prevent the fluids from the seminal vessels 

 and from the ducts of the prostate gland, falling- 

 back into the bladder, as also to protect the ori- 

 fices of these ducts from exposure to the urine 

 when the bladder is closed, and that without 

 this arrangement it would be inconceivable how 

 the contents of the vesiculae seminales could be 

 discharged forwards, or how the urine could be 

 retained while the seminal discharge was being- 

 made. We must remark, that after frequent 

 examinations of this region, we cannot satisfy 

 ourselves of the existence of this particular ar- 



* Treatise on Diseases of the Urethra, &e. ]'. 14. 



rangement, although we are convinced that the 

 orifice is furnished with a sphincter such as we 

 shall presently describe. Moreover, we. believe 

 that the prostatic secretion is more or less ex- 

 pressed at each evacuation of the urine, inas- 

 much as the longitudinal, the principal detrusor 

 fibres of the bladder, are fixed into, expand 

 upon, and must compress this gland, especially 

 at the commencement of the process, although 

 they obviously can have no effect on the vesi- 

 culce seminales, vasa deferentia, or their contents. 

 The existence of a true muscular sphincter 

 is denied by Sabatier, Anat. torn. ii. p. 403; 

 Marjolin, torn. ii. p. 473; also by Bichat, 

 Anat. desc. torn. v. p. 147; byBoyer, Anat. 

 torn. iv. p. 490 ; by Cloquet, Anat. torn. ii. p. 

 1050; by Portal, Anat. torn. v. p. 401; the 

 latter, however, describes the urethral orifice as 

 surrounded by oblique muscular fasciculi. 

 Winslow also, Anat. torn. ii. p. 210, denies a 

 true sphincter, but ascribes the office of such 

 to the muscular fasciculi which pass from the 

 pubis to the bladder. Wilson (Lectures on the 

 Urinary and Genital Organs, p. 57,) denies 

 the existence of any regular sphincter, but 

 thinks, from the distribution of some fibres 

 at the beginning of the urethra, and which pass 

 round it semicircularly from the forepart and 

 meet the descending fibres behind, that the 

 contraction of these, assisted by those of the 

 urethra nearer the penis (compressores urethra), 

 may be considered as sufficient to prevent the 

 urine passing from the bladder into the urethra. 

 Several of the foregoing writers who deny a 

 muscular sphincter to the bladder, consider, 

 nevertheless, that its orifice is closed by a pe- 

 culiar tissue which resists the ordinary tendency 

 of the muscular coat to expel its contents, but 

 which is capable of yielding to the increased 

 force which is exerted in the ordinary evacua- 

 tion. Thus Bichat describes, as placed between 

 the mucous lining and the external cellular 

 tissue, a dense white fibrous substance, con- 

 tinuous with the muscular fibres which are in- 

 serted into it, a small process of this prolonged 

 posteriorly to the uvula, and another anteriorly 

 to the verumontanum. This substance is 

 not muscular, and presents a passive organic 

 resistance. Cloquet, Boyer, and Marjolin con- 

 cur in the same account ; it is difficult, how- 

 ever, to reconcile with such a condition of parts 

 the phenomena which not un frequently occur 

 in disease, such as paralysis and incontinence 

 of urine in cases of injury of the spine, or of the 

 nervous system; or again, retention of urine 

 from irritation in this situation caused either by 

 local inflammation, or through sympathy with 

 some adjacent diseased organ, or by some pe- 

 culiar acrimony in the urine. A muscular struc- 

 ture is more reconcilable with these, and with 

 many other pathological facts, than an elastic, 

 or fibrous, or resisting tissue, such as this part is 

 stated to be furnished with. The result of our 

 examination convinces us that the organization 

 of this part is very peculiar, and that the neck 

 of the bladder is closed by a power more than 

 thatof a mere elastic tissue. Elasticity no doubt 

 resides in this structure, and we admit to a con- 

 siderable extent, as it does in almost every ani- 



