STRICTURE OF THE BLADDER. 731 



The lateral ligaments, broader and thinner than the preceding, are attached to 

 the lateral parts of the prostate, and to the sides of the base of the bladder. 



The urachus is the fibro-muscular cord already mentioned, extending between 

 the summit of the bladder and the umbilicus. It is broad below, at its attachment 

 to the bladder, and becomes narrower as it ascends. 



The false ligaments of the bladder are, two posterior, two lateral, and one 

 superior. 



The two posterior pass forwards, 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 fold of peritoneum, 

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

 nerves. 



The two lateral ligaments are reflections of the peritoneum, from the iliac fossa3 

 to the sides of the bladder. 



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

 summit of the bladder to the umbilicus. It covers the urachus, and the obliterated 

 hypogastric arteries. 



Structure. The bladder is composed of four coats : a serous, a muscular, a cel- 

 lular, and a mucous coat. 



The serous coat is partial, and derived from the peritoneum. It invests the 

 posterior surface, from opposite the termination of the two ureters to its summit, 

 and is reflected from this point and from the sides, on to the abdominal and pelvic 

 walls. 



The muscular coat consists of two layers of unstriped muscular fibre, an 

 external layer, composed of longitudinal fibres, and an internal layer of circular 

 fibres. 



The longitudinal fibres are most distinct on the anterior and posterior surfaces 

 of the organ. They arise, in front, from the anterior ligaments of the bladder, 

 from the neck of the bladder, and, in the male, from the adjacent portion of the 

 prostate gland. They spread out, and form a plexiform mesh, on the anterior 

 surface of the bladder, being continued over the posterior surface and base of 

 the organ to the neck, where they are inserted into the prostate in the male, and 

 into the vagina in the female. 



Other longitudinal fibres arise, in the male, from the sides of the prostate, and 

 spread out upon the sides of the bladder, intersecting with one another. 



The circular fibres are very thinly and irregularly scattered on the body of 

 the organ ; but, towards its lower part, round the cervix and commencement of the 

 urethra, they are disposed as a thick circular layer, forming the sphincter vesicse, 

 which is continuous with the muscular fibres of the prostate gland. 



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

 converge to the back part of the prostate gland, and are inserted, by means of a 

 fibrous process, into the middle lobe of this organ. They are the muscles 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 urine into them. 



The cellular coat consists of a layer of areolar tissue, connecting together the 

 muscular and mucous coats, being intimately connected with 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 the urethra. It is connected loosely to the muscular coat, by a layer of 

 areolar tissue, excepting at the trigone, where its adhesion is more close. It is 

 provided with a few mucous iollicles, and numerous small racemose glands, 

 lined with columnar epithelium, exist near the neck of the organ. The epithe- 

 lium covering it is intermediate in form between the columnar and squamous 

 varieties. 



Interior of the bladder. Upon the inner surface of the base of the bladder, 

 immediately behind the urethral orifice, is a triangular, smooth surface, the apex 



