THE BLADDER. 1143 



The lateral tii/ament*. also formed by the recto-vesical fascia, are broader and 

 thinner than the preceding. They are attached to the lateral parts of the prostate 

 and to the -ides of the bladder and the pelvic wall. The posterior prolongation of 

 this ligament is known as the ligament of the rectum. 



The ui-achu* is the fibro-muscular cord already mentioned, extending between 

 the summit of the bladder and the umbilicus. It is broad below, and becomes 

 narrower as it ascends. 



The fah>- ligament* of the bladder are two posterior, two lateral, and one 

 superior. 



The t>i'o posterior pass forward, in the male, from the sides of the rectum ; in 

 the female, from the sides of the uterus to the posterior and lateral aspect of the 

 bladder : they form the lateral boundaries of the recto-vesical cul-de-sac of the 

 peritoneum, and contain the obliterated hypogastric arteries and the ureters, 

 together with vessels and nerves. 



The two lateral ligaments are reflections of the peritoneum from the iliac fossae 

 to the sides of the bladder, along the line of the obliterated hypogastric arteries. 



The superior ligament is the prominent fold of the peritoneum extending from 

 the summit of the bladder to the umbilicus. It covers the urachus and the oblit- 

 erated hypogastric arteries. 



Structure. The bladder is composed of four coats serous, muscular, sub- 

 mucous, and mucous. 



The xermix --"at is derived from the peritoneum. It invests the entire superior 

 surface, the upper part of the base, and each side, above and behind the '* hypo- 

 gastric cord." and is reflected on to the abdominal and pelvic walls. 



The muscular coat consists of three layers of unstriped muscular fibre : an 

 external layer, composed of fibres having for the most part a longitudinal arrange- 

 ment : a middle layer, in which the fibres are arranged, more or less, in a circular 

 manner: and an internal layer, in which the fibres have a general longitudinal 

 arrangement. 



The fibre* of the external longitudinal layer arise from the posterior surface of 

 the body of the os pubis in both sexes (musculi pubo-vesicalis). and in the male from 

 the adjacent part of the prostate gland and its capsule. They pass, in a more or 

 less longitudinal manner, up the anterior surface of the bladder, over its apex, 

 and then descend along its posterior surface to its base, where they become 

 attached to the prostate in the male and to the front of the vagina in the female. 

 At the sides of the bladder the fibres are arranged obliquely and intersect one 

 another. This layer has been named the detrusor urince muscle. 



The middle circular layers are very thinly and irregularly scattered on the body 

 of the organ, and, though to some extent placed transversely to the long axis of the 

 bladder, are fr the most part arranged obliquely. Toward the lower part of the 

 bladder, round the cervix and commencement of the urethra, they are disposed in 

 a thick circular layer, forming the sphincter vesica>. which is continuous with the 

 muscular fibres of the prostate gland. 



The internal longitudinal layer is thin, and its fasciculi have a reticular 

 arrangement, but with a tendency to assume for the most part a longitudinal 

 direction. 



Two bands of oblique fibres, originating behind the orifices of the ureters, 

 pa<- between these orifices and also converge to the back part of the prostate gland, 

 and are inserted, by means of a fibrous process, into the middle lobe of that organ. 

 They are the //;//.^-/V.< of the ureters, described by Sir C. Bell, who supposed that 

 during the contraction of the bladder they served to retain the oblique direction of 

 the ureters, and so prevent the reflux of the urine into them. 



The sitbmueotu coat consists of a layer of areolar tissue connecting together the 

 muscular and mucous coats, and intimately united to the latter. 



The mucous coat is thin, smooth, and of a pale rose color. It is continuous 

 through the ureters with the lining membrane of the uriniferous tubes, and below 

 with that of the urethra. It is connected loosely to the muscular coat by a layei 



