3&C BLADDER, NORMAL ANATOMY. 



retained for a considerable time although it was The trigone in the female bladder comprises 

 subjected to pressure, and was afterwards eva- a smaller area, but is broader in proportion 

 cuated through the urethra when the ligature on than in the male; it is not so distinct or firm 

 the latter was removed. No alteration whatever in the former as in the latter, where it is sup- 

 from the ordinary appearances was observed ported not only by a dense substratum, but 

 either during the distension or the subsequent also by the vasa deferentia, vesiculae seminales, 

 emptying of its cavity, nor did any regurgi- and prostate gland. This portion of the 

 tation take place into the ureters in either bladder is so firm and incompressible that it is 

 state. The same experiment with air instead probable the cavity corresponding to it can 

 of water was repeated and with the same effect, never be wholly obliterated, so that in the most 

 It may be further observed that the ductus contracted bladder a few drops of fluid are 

 communis choledochus enters the duodenum in still retained. The uvula, like other similar 

 a similar oblique way, that no regurgitation portions of the mucous membrane, is subject 

 from the intestine ever occurs into it, and yet to infiltration and increase of size in acute in- 

 there is no peculiar muscular fasciculus attached flammatory affections, as also to chronic and 

 to its orifice which could execute the office permanent enlargement ; and as it lies nearly 

 ascribed to these lateral boundaries of the tri- over, but a little anterior to the middle lobe 

 gone. To these muscles Sir C. Bell also of the prostate gland, it is therefore difficult, 

 attributes the projection into the bladder of the and in most cases impossible to distinguish 

 third lobe of the prostate gland, usually called affections of the latter from those of the former. 

 the middle or Howe's lobe, when this part is in The uvula is smaller in the female than in the 

 a state of enlargement. There are, however, such male ; hence the opening from the bladder into 

 plain and simple reasons for this tumour be- the urethra is larger in the former than in the latter, 

 coming prominent in this direction rather than Organization of the bladder. a. Arteries. 

 in any other, that it is unnecessary to search for In the normal state the bladder is not very 

 an explanation in the action of these muscles, vascular ; we have already mentioned that its 

 the undoubted development of which in such inner surface is pale and free from any red 

 cases may with a much greater degree of pro- vessels. The arteries, however, of the bladder 

 bability be considered as one of the effects and are very conspicuous when they have been in- 

 not as the cause of this projection. jected; they are long and tortuous, and are 

 The uvula or apex of the trigone varies very distributed chiefly along the sides, inferior 

 much in its appearance in different persons, region, and cervix. They are derived from 

 In the normal state it is very small, and is various sources. The internal iliac or hypo- 

 most distinctly seen by making only a small gastric on each side, just before its ligamen- 

 openmg in the upper region of the bladder tous termination, sends off one or two vesical 

 when in situ, and looking down towards the branches, which ramify on the superior and 

 cervix ; it then appears as a small projection lateral regions ; the middle haemorrhoidal and 

 in the middle line of the orifice of the urethra, internal pubic also very generally send some 

 which opening it thus assists to close or to fill, considerable branches to its inferior region and 

 It is much effaced by opening the bladder from cervix; the obturator and epigastric vessels 

 the urethra after its removal from the subject, also very frequently send small arteries to it 

 the mucous membrane being then easily ex- anteriorly. When the bladder is distended, all 

 tended. This projection is only a slight full- these vessels are seen very distinctly, and in 

 ness or prominence of the mucous membrane the muscular coat much more than in the sub- 

 with an increase in the submucous tissue, in mucous tissue, contrary to what may be ob- 

 which small follicles or cryptse maybe dis- served in the other hollow viscera; this, how- 

 cerned . This part appears rather vascular, and ever, is accounted for by recollecting that the 

 probably possesses some peculiar organization ; mucous coat of the bladder does not in its 

 the situation also which it holds, as well as its normal and healthy condition possess, nor does 

 structure, appear to indicate it to be the seat of it indeed require any high degree of organi- 

 a proper sensibility, which, when affected, ex- zation, as it is simply a reservoir, and has no 

 cites the irritability of the whole organ. Many important function to execute further than to 

 facts which manifest themselves in the treat- secrete a fine mucous fluid which lubricates its 

 ment of urinary diseases seem to corroborate surface and defends it from the irritation of the 

 this idea : thus, when a calculus is pressed urine. This secretion mingles with the urine, 

 against this part of the mucous membrane, the the properties of which it alters in a remark- 

 pain is insupportable, whereas when it falls or able manner whenever it is increased in quan- 

 is directed into the inferior fundus, the pain is tity, as occasionally occurs in chronic disease 

 comparatively trifling ; also when a bougie or of this organ. The muscular coat of the blad- 

 catheter is being passed into the bladder, a der is the essential agent in expelling its cori- 

 peculiarly acute sensation is experienced as the tents, and is therefore more fully supplied with 

 instrument comes in contact with this par- vessels than any other of its tunics, 

 ticular prominence. The uvula in the child is b. Veins. The veins of the bladder are 

 the most depending part of the bladder, at large and numerous inferiorly, and in old per- 

 least in the erect posture ; this is not the case sons in particular. There are but few on the 

 in the adult; hence probably we have in part superior and lateral regions except towards the 

 the reason why calculus is more painful in the inferior part of the latter. In the child the 

 former than in the latter. veins are very inconsiderable : this difference 



