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under the name of detrutor vrintf : it is composed of pale 

 fibres interlacing in all direction*; three distinct ! 

 have been described, but it is sufficient for all useful pur- 

 poses to nay, that the superficial fibres are directed in the 

 course of the axis of the bladder ; that at the sides they are 

 more and more oblique ; and that the more internal fibres 

 assume a circular direction as they approach the neck of the 

 bladder, so that some anatomists have descnl>ed them in 

 this part as a distinct muscle, under the name of sphincter 

 . . This reticulated structure of the muscular coat 

 en ihles the bladder to contract so perfectly as to expel 

 every drop of its contents. 



When the bladder is much distended, the muxeular coat 

 liccomcs attenuated to such a degree, that it is ditlicult to 

 distinguish it from cellular tissue. Sometimes its fibres 

 become so much cnlarued from the effects of long-continued 

 irritation and overaction of the origin, that they form pro- 

 jecting lines or columns under the mucous coat ; this ap- 

 pcnrancc of the bladder is designated by the French / 'exxie 

 ii chlorines. The mucous membrane is occasionally pro- 

 truded between these columns, forming sacs, or. pouches, in 

 which urinary calculi are sometimes lodged ; these calculi are 

 t hen said to be encysted or sacculated. The muscular coat is 

 united to the third, lost, or mucous coat by a distinct layer of 

 cellular tissue, to which the term nervous or vascular coat 

 i> -mnctimes improperly applied. The mucous coat, or lining 

 of the bladder, belongs to that division of the mucous mem- 

 branes, denominated genito-vrinary : it not only line* the 

 bladder, but is prolonged upwards along the ureters into the 

 kidney, and downwards along the urethra; it is of a palo 

 rose-colour, is smooth when the bladder is distended, and 

 corrugated when it is empty ; it secretes a viscid fluid termed 

 mucus, which protects it from the acrimony of the fluid 

 with which it is constantly in contact. Three openings are 

 seen in it, two situated posteriorly, about an inch and a half 

 from each other, which are the openings of the ureters ; and 

 one anteriorly, which is the opening of the urethra. Extend- 

 ing from the openings of the ureters to that of the urethra 

 are observed two prominent lines, which are formed by 'mus- 

 cular fibres elevating the mucous coat : these lines form the 

 sides of a triangle, the base of which is an imaginary lint- 

 drawn between the openings of the ureters ; the apex is at 

 the urethra. The space thus marked out is denominated 

 the trigone vesicate: it is paler than the rest of the internal 

 surface of the bladder, is possessed of peculiar sensibility, 

 and is smooth in the contracted as well as in the distended 

 condition of the bladder. 



The two prominent lines which form the sides of the 

 trigone vestcaie, according to Sir C. Bell, are distinct 

 muscles, the muscles of the ureters. They have their fixed 

 point or origin at that prominence or tubercle existing at 

 the inferior surface of the urethra, which has been already 

 described as formed by the middle lobe of the prostate, their 

 insertion or movcable point being at the opening of the 

 ureters. Their use is to assist in the contractions of the blad- 

 der, to support and close the mouths of the ureters, and to 

 preserve the obliquity of these canals by drawing them 

 down during the contractions of the bladder. The tubercle, 

 whence these muscles are supposed to take their origin, is 

 termed the luette or uvula vesicee : but these terras ore more 

 particularly applicable to it when enlarged and diseased. It 

 then forms a prominent tumour at the orifice of the urethra, 

 :u'!* the part of a valve, and becomes a troublesome cause 

 of retention of urine. 



The arteries of the bladder arc derived from the internal 

 iliac and its branches ; its veins empty themselves into the 

 internal iliac vein : these vessels arc most abundant about 

 its neck and bas fond. The lymphatics follow the course 

 of these vessels. The nerves are of two kinds, the one 

 derived fiom the sacral plexus of the cerebro-spinal sys 

 tern, the nerves of animal life; the other derived from the 

 Inpuastttc plexus of the sympathetic, the nerves of or- 

 g.inii: life. 



The secretion of the urine is performed by the kidneys ; 

 it is constantly going on, and does not exhibit those alter- 

 nations of action and r< -|..>M- observable in the oilier secret - 

 ingot-gulf. Tim rapidity with which certain diuretics arc 

 eliminated with the urine has induced several physiologists 

 t i imagine that lluids are conveyed from the stomach to 

 tin' bludder by a more direct route than the circuitous one 

 f absorption and of the circulation. Hut no ducts or chan- 

 nel* which could answer thi-, purpose have 1 n discovered, 



nor is their existence necessary, for it is calculated that 



1000 ounces of blood circulate through the kidneys in the 

 pace of an hour; and if only a tenth part of this be sepa- 

 rated by the kidneys, 100 oun< i pounds and a 

 quarter, may be given out in this short spare of time. It is 

 not however improbable that the lymphatic-, inn) convey 

 lluids directly from the stomach to the bladder. 



The urine being secreted, dribbles along the ureters, and 

 its descent is probably aided by the contr.ietihu 

 tubes and the impulse iif the neighbouring arteries. It drops 

 into the bladder and gradually distends it, but it is pre- 

 vented from regurgitating into the ureters in omseqi.. 

 of these tubes taking an oblique course between the i 

 cular and mucous coats before they perforate the hittc 

 the urine accumulates, these tubes are more and more 



d, and the obstacle to rcgurgitation is increased : l.ut 

 the column of urine descending along the meters, Ix-mg 

 higher than that contained in the bladder, is not prevented 

 from entering into it. 



When a sullicient quantity of urine is accumulated in the 

 bladder, varying according to the degree of irritability of 

 the organ, a general uneasy scn-alion is produced, and a 

 more particular one referred to the trigone vesicate; the 

 diaphragm and abdominal muscles are called into action, 

 the resistance of the neck of the bladder is overcome (the 

 sphincter, if we admit its existence, relaxes), the muscular 

 fibres of the bladder contract, and are able without further 

 assistance to evacuate every drop of its contents. 



Congenital malformations of the bladder are not unfrc- 

 quent. Morgagni describes a case in which it was ol' a 



}>rismatic form, another in w Inch it was of double its natural 

 ength, and another in which the fundus was as large u 

 bas fond. Haller observed it much uinl jiermaneiith 

 stricted at its body. Sometimes the bladder is altogether 

 wanting, in which eases the ureters open either into the 

 rectum, as into the cloaca of birds, at the pubes, or imme- 

 diately into the urethra. But a more frequent malforma- 

 tion is that, where the inferior portion of the recti mi 

 being imperfect, and the anterior wall of the bladder defi- 

 cient, the posterior wall is protruded, and forms a red 

 fungous-like tumour above the pubcs. This tumour pre- 

 sents two orifices which are the mouths of the ureters, from 

 which the urine constantly dribbles; this species of mal- 

 formation is peculiarly interesting, as it has enabled phy- 

 siologists to determine the manner in which the urine d 

 into the bladder. In some rare cases of imperforatioii of the 

 urethra, the urine, being prevented from escaping by this 

 canal, has dilated the urachus and escaped at the um- 

 bilicus or navel. M. Deschamps, IIOWVUT, imagines that 

 all the cases which have been described as dilatations of 

 the urachus are not in reality such, but that the muscular 

 coat of the bladder having given way in some point, the 

 mucous coat has been protruded or extended by the pressure 

 of the urine, has followed the course of the umbilical cord, 

 and then burst at the umbilicus. Cases are on record of 

 individuals who have had more than one bladder. Thus, 

 Blassius describes a case in which it was double. Mollinetti 

 found in a female whom he dissected live kidneys, five 

 ureters, and five bladders. It sometimes but rarely hap- 

 pens, that the bladder is divided into cells, but 1 

 of malformation in all probability is not congenital. The 

 bladder is liable to inflammation, which may invade the 

 totality of the organ or its coats separately ; and this may- 

 be acute or chronic. When the mucous membrane is in- 

 flamed, the organ becomes exceedingly irritable, and there 

 instant call to discharge its contents. In coliseum -m > 

 of inflammation, ulcers, gangrenous spots, and indurations 

 of different kinds may be produced, and its secretion may be 

 increased and altered : to this state the term catarrh of the 

 bladder is applied. Sometimes the parictcs of the bladder 

 become exceedingly thick. The mucous membrane some- 

 times is found in a varicose stntc : it sometimes gives origin 

 to cysts of different kinds, and fungous growths, which latter 

 are found more particularly in old people; sometime- 

 it protrudes through the muscular coat and forms hermit. 

 Many cases are on record in which worms have been dis- 

 charged from the bladder. The bladder is sometimes p'.i- 

 : 1 through the inguinal or femoral canals, forming a 



hernia of the bladder, or cystocele, which is always readily 

 distinguished from other hernia! by the regular diminution 

 of the swelling when the urine is passed. 



Various accidents and diseases may prevent the bladder 

 from evacua ntenN, in which case the organ be- 



comes inordinately distended, and unless relieved, the dis- 



