378 



BLADDER, NORMAL ANATOMY. 



more does its form resemble that of inferior 

 animals, and it is an organ very fully developed 

 in the young of all animals who possess it. 

 This organ, in the adult male, when empty or 

 contracted, is a flattened triangle, the transverse 

 and vertical axes being considerably greater 

 than the antero-posterior one; in this con- 

 dition the bladder is buried deep in the pelvis, 

 behind and partly below the symphysis pubis; 

 the base of the triangle is in front of but not 

 very closely applied to the rectum, unless the 

 cavity of the latter be fully distended. When 

 the bladder is expanded in tin 1 adult male to 

 that moderate degree which in perfect health 

 usually excites a slight feeling or desire to void 

 the urine, and when the quantity accumulated 

 may amount to half a pint or upwards, its 

 figure is then somewhat oval, its vertical axis 

 being considerably greater than either the 

 transverse or the antero-posterior, the two latter 

 being then nearly equal. The larger end of 

 this ovoid sac rests inferiorly and posteriorly 

 on the rectum, and is of an irregular form ; the 

 smaller end, which is more regularly sphe- 

 roidal, is directed upwards towards the abdo- 

 men, and somewhat forwards, and occasionally 

 also a little towards the left side. When the 

 bladder is over-distended from any cause, it 

 becomes considerably increased in every dia- 

 meter; it first expands in its lower and middle 

 portions, until the pelvic parietes resist ; 

 it then enlarges superiorly to an indefinite 

 degree, and at the same time the whole organ 

 rotates a little forwards by its superior, and a 

 little backwards by its inferior fundus. Its 

 figure in this over-distended condition is not 

 merely enlarged, but it also presents a totally 

 different, or rather a reversed shape : the larger 

 extremity of the oval is now superior, occu- 

 pying the hypogastric region, which it ren- 

 ders prominent and tense in a degree propor- 

 tioned to its distension. These observations as 

 to the form of the bladder will not apply in 

 every instance, as occasionally this viscus pre- 

 sents irregularities both in size and shape, as 

 well as in the density and delicacy of its tunics. 

 The bladder in the female child does not differ 

 from that of the male of the same age, but in 

 the adult of each sex it presents peculiarities. 

 In the contracted state it is nearly similar in 

 each, only somewhat flatter in the female. 

 When distended, in the latter it presents a more 

 triangular form, the sides somewhat rounded, 

 than it does in the male, where the ovoid form 

 prevails ; in the female its lower fundus admits 

 of greater lateral extension in conformity with 

 the shape of the pelvis, and its transverse axis 

 is longer in proportion than in the male ; hence 

 it assumes the triangular more than the oval 

 figure. This character is more remarkable in 

 the female who has borne children than in the 

 virgin; in the former the bladder, when dis- 

 tended, appears to exhibit the effects of the 

 pressure of the uterus posteriorly, and of the 

 pubes anteriorly, being flattened in each of 

 these aspects : in some instances it resembles a 

 small barrel placed tranversely. 



In the fa'tus and infant of a year old the 

 bladder in figure more resembles that of a qua- 



druped; when distended, it is pyriform, like a 

 bottle or a flask reversed, the larger end, or the 

 superior fundus being in the abdomen, and 

 the smaller extremity tapering into the urethra. 

 This is the only portion in the pelvis; at this 

 age its vertical axis greatly exceeds its other 

 diameters, and even when empty the greater 

 portion of it is in the abdomen. As the child 

 increases in years and size, its pelvis expands, 

 the bladder gradually descends into this region, 

 and in the same proportion its lower fundus 

 enlarges, so that at about six or seven years of 

 age it presents a more oval form, both extremi- 

 ties being nearly equal, and very little of it 

 rising above the pubis, unless when distended. 

 From this period it continues to acquire gra- 

 dually the adult figure; that is, its inferior 

 fundus and body enlarge, while the superior re- 

 mains stationary ; hence it becomes shorter in its 

 proportions, and broader below, so as to assume 

 the triangular shape when empty, and the ovoid 

 when distended. About two months before birth 

 the bladder is very much elongated, its upper 

 extremity being somewhat pointed, and ap- 

 proaching the umbilicus in the direction of the 

 urachus. When distended, it presents some- 

 what the appearance of a cylinder contracted 

 at each extremity. Soon after birth the upper 

 fundus becomes rounder, and then it acquires 

 the pyriform figure, which in the course of a 

 few years undergoes the gradual alterations that 

 have been already noticed. 



The capacity of the bladder in the adult 

 cannot be accurately ascertained, as it varies 

 from a number of circumstances, such as age 

 and sex, health and disease : thus irritation 

 general or local, ischuna renalis, cholera, &c., 

 will cause it to contract, while retention of 

 urine, paralysis, fever, &c., will allow it to 

 enlarge. Custom or habit will also affect it, 

 likewise the position of the body, pregnancy, 

 the nature or peculiar quality of diet, the tem- 

 perament of the individual, the temperature of 

 the atmosphere, the state of society, &c. In 

 the same individual it will at one time contract 

 so as to retain only a few drops, and at another 

 it will dilate so as to contain one, two, and 

 even three pints. Generally it is more capa- 

 cious in women, particularly in those who have 

 borne children, than in men. 



In children the bladder, although very dis- 

 tensible under certain circumstances, is usually 

 less capacious in proportion than in the adult 

 or old, probably because it is more muscular 

 and irritable ; and hence, too, the more fre- 

 quent desire to contract and empty its contents. 



When the bladder is moderately distended, 

 anatomists and pathologists have been in the 

 custom of dividing it into four regions for the 

 purpose of more accurate description ; viz., the 

 superior part or the upper fundus, the middle 

 part or body, the inferior part or the lower 

 fundus, and the cervix or neck. This arrange- 

 ment is not very correct, for it can only apply 

 to this organ when distended ; the term su- 

 perior fundus also is obviously objectionable, 

 and was probably derived from examining this 

 viscus in other animals, or in the human fetus 

 where the lower fundus does not exist ; neither 



