B L A 



495 



B L A 



its figure is that of a short oval, compressed at the fore and 

 back part ; its lower surface subsides on the rectum, and 

 expanding forms what is termed by anatomists the has 

 fond of the bladder. This change of form is dependent not 

 only upon the enlargement of the cavity in which the 

 bladder is contained, but also upon the weight of the fluid 

 which it habitually sustains, and thus in advanced age it is 

 more deeply sunk in the pelvis than in the middle periods 

 of life. In the female its transverse diameter is greater 

 than in the male, in consequence of the antero-posterior 

 diameter of the pelvis being encroached upon by the uterus. 

 Its capacity varies in the different periods of life ; and, as a 

 general rule, it may be said to increase in proportion as the 

 individual advances in years, and to be greater in females 

 than in males. Its capacity is modified in different in- 

 dividuals by their habits and the natural exercise of its 

 functions. It is more particularly changed by disease : 

 thus, from the effects of long-continued irritation, it may be 

 reduced to such a state that it will not contain more than a 

 few drops of urine ; and on the contrary when, from any 

 cause, its contents cannot be duly evacuated, it may be dis- 

 tended so as to contain many quarts of urine, and occupy a 

 large proportion of the abdomen. Its ordinary capacity may 

 be estimated at a pint and a half. 



Fig. 1. 



[The Ureters, running from the kidneys to the bladder.] 

 a Aorta, b Bifurcation, c Alxlomiiml musclos turned down, d The Rectum 

 out and tied, e Bladder. // Ureters, g g Kidneys. 



Fig. 2. 



/ 



3 A / # 



[Side view of the Bladder of an adult male.] 



n I'nlK*s. It Sacrum, c Recti muscles, d d Rectum, e IJladder. / Vas 

 ilt'fVn'iis. g Ureter, h Vesicula seminalis. i Prostate gland, j Urethra. 

 ft h k Peritonaeum, reflected from rectum upon bladder, thence upon the recti 

 muscles. 



The direction of the bladder is oblique, being inclined 

 somewhat forwards and upwards ; in proportion to the degree 

 of distension the obliquity is increased, in consequence of 

 the neck being fixed. It ia retained in its position by two 

 lateral ligaments, one on each side, and an anterior liga- 

 ment ; the lateral ligaments are prolongations of the/<wem 

 iliaca, which, passing down into the pelvis, assumes the 

 name of fascia pelvica, and becomes identified with the 

 prostate gland and side of the bladder ; the anterior liga- 

 ment is double, and it is formed by the fascia transversalis, 

 which, passing down behind the symphysis pubis, is reflected 

 upon the upper surface of the prostate gland ; from the 

 point of reflection two strong fasciculi of fibres pass to the 

 anterior surface of the bladder. These ligaments arc some- 



times called the proper ligaments of the bladder to distin- 

 guish them from certain folds of the peritonaeum, sometimes 

 called false ligaments. As the bladder is peculiarly inte- 

 resting in a surgical point of view, anatomists have endea- 

 voured to describe it precisely, and with this view they 

 have divided it into six regions or surfaces, an anterior, 

 a posterior, two lateral, a superior, and an inferior. 



The anterior surface, in the collapsed state of the organ, 

 lies behind the symphysis pubis, with which it is connected 

 by loose cellular tissue ; when distended, the bladder rises, and 

 its anterior surface comes in relation, or in contact, with the 

 recti muscles of the abdomen. The posterior surface is 

 covered by the peritonaeum, which in the male is reflected 

 upon it from the rectum, in the female from the uterus and 

 vagina : it is then reflected from the sides of the bladder to 

 the iliac fossa ; at the points of reflection it forms folds, 

 one on each side and two posteriorly : these have been im- 

 properly described as ligaments, for instead of- confining 

 the bladder they serve rather as provisions to facilitate its 

 expansion. 



The lateral regions are partially covered by the peri- 

 tonaeum ; running along them we find the umbilical arte- 

 ries, or their remains, in both sexes, and the vasa deferentia 

 in the male. The superior region, or fundus, is partially 

 covered by the peritonaeum, which is reflected thence on to 

 the inner surface of the recti muscles : it has a fibrous cord 

 attached to it termed the urachus, which lies between the 

 peritonaeum and the recti muscles, and being accompanied 

 by the remains of the umbilical arteries, extends to the um- 

 bilicus, where it becomes identified with the abdominal 

 aponeuroses. This fibrous cord appears to be useful in re- 

 taining the bladder in its situation, for never in the human 

 subject, except in certain cases of malformation, which aro 

 very rare, does it present the form of a canal, such as it is 

 found to be in the young of certain quadrupeds, in which 

 it is the medium of communication between the bladder and 

 a bag, or sac, termed the allantoid. 



The inferior region, or bos fond, is the most important in 

 a surgical point of view. It has no precise lines of demar- 

 cation laterally, but is bounded before by the prostate gland, 

 behind by the peritonasum, which is reflected upon the pos- 

 terior surface of the bladder. Attached to it we find in the 

 male the vesiculoo seminales and the vasa deferentia, which, 

 in converging to the prostate gland, leave between them a 

 triangular space, where the bladder is only separated from 

 the rectum by a considerable quantity of fatty cellular 

 tissue containing many vessels, principally veins : this rela- 

 tion of the bladder to the rectum explains many circum- 

 stances respecting their particular diseases. In the female 

 this region rests on the vagina, which separates it from 

 tha rectum. We have seen that the anterior and in- 

 ferior regions of the bladder are left completely uncovered 

 by the peritonaeum, a fact which is of the utmost import- 

 ance to the surgeon, for in consequence of it he is enabled 

 to perform operations on these regions without injuring 

 this membrane, which when wounded in any operation 

 places the life of the patient in a hazardous state, in 

 consequence of the rapidity with which inflammation ex- 

 tends along it. 



The neck, or constricted portion of the bladder, is com- 

 pared to a truncated cone, longer at the sides and below 

 than above. In infancy, owing to the position of the blad- 

 der, its direction is oblique ; for a similar reason it is hori- 

 zontal in the adult : it differs in structure from the rest of 

 the organ. The neck, which is formed of a somewhat 

 fibrous whitish substance, is the connecting medium between 

 the bladder and the urethra. Its posterior part rests on the 

 rectum ; its anterior is surrounded, at least below and at the 

 sides, by the prostate gland, which is peculiar to the male, 

 and is composed of an aggregation of mucous follicles, dis- 

 posed so as to form three lobes, one on each side of the 

 neck of the bladder, and one below called the middle lobe, 

 which forms a slight projection into the opening of the 

 urethra. 



The bladder, like the other hollow viscera, is composed of 

 three layers, or coats, united to each other by cellular tissue ; 

 these coats are the peritoneal or serous, the muscular, and 

 the mucous. The peritonceal coat has been already de- 

 scribed as investing only a portion of the organ ; it is united 

 to the muscular coat by cellular tissue, which is extended 

 over the whole of the latter, being however thinner under 

 the peritonaeal coat than elsewhere. The muscular coat has 

 been described by some anatomists as a distinct muscle 



