530 LIGAMENTS OF THE BLADDER. 



directed from above, obliquely downwards and backwards. It is 

 divided into body, fundus, base, and neck. The body comprehends 

 the middle zone of the organ ; the fundus, its upper segment ; the 

 base, the lower broad extremity, which rests upon the rectum ; and 

 the neck the narrow constricted portion which is applied against the 

 prostate gland. 



This organ is retained in its place by ligaments which are divided 

 into true and false ; the true ligaments are seven in number, two 

 anterior, two lateral, two umbilical, and the urachus ; the false liga- 

 ments are folds of the peritoneum, and are four in number, two an- 

 terior and two posterior. 



The interior ligaments are formed by the pelvic fascia, which 

 passes from the inner surface of the os pubis, on each side of the 

 symphysis, to the front of the bladder. ; 



The Lateral ligaments are formed by the reflection of the pelvic 

 fascia from the levatores ani muscles, upon the sides of the base of 

 the bladder. 



The Umbilical ligaments are the fibrous cords which result from 

 the obliteration of the umbilical arteries of the foetus ; they pass for- 

 wards on each side of the fundus of the bladder, and ascend beneath 

 the peritoneum to the umbilicus. 



The Urachus is a small fibrous cord formed by the obliteration of 

 a tubular canal existing in the embryo ; it is attached to the apex of 

 the bladder, and thence ascends to the umbilicus. 



The False ligaments are folds of peritoneum, the two lateral cor- 

 respond with the passage of the vasa deferentia, from the sides of 

 the bladder to the internal abdominal rings, and the two posterior 

 with the course of the umbilical arteries, to the fundus of the organ. 



The bladder is composed of three coats, an external or serous 

 coat, a muscular and a mucous coat. The serous coat is partial, 

 and derived from the peritoneum, which invests the posterior sur- 

 face and sides of the bladder, from about opposite the point of termi- 

 nation of the two ureters to its summit, whence it is guided to the 

 anterior wall of the abdomen by the umbilical ligaments and urachus. 

 The muscular coat consists of two layers, an external layer com- 

 posed of longitudinal fibres, the detrusor urinae ; and an internal 

 layer of oblique and transverse fibres irregularly distributed. The 

 anterior longitudinal fibres commence by four branches (the tendons 

 of the bladder, or of the detrusor urinas), two superior from the os 

 pubis, and two inferior from the ramus of the ischium on each side, 

 and spread out as they ascend upon the anterior surface of the blad- 

 der to its fundus ; they then converge upon the posterior surface of 

 the organ, and descend to its neck where they are inserted into the 

 isthmus of the prostate gland, and into a ring of elastic tissue, which 

 surrounds the commencement of the prostatic portion of the urethra. 

 Some of the anterior fibres are also attached to this ring. The 

 lateral fibres commence at the prostate gland and the elastic ring of 

 the urethra on one side, and spread out as they ascend upon the 

 side of the bladder to descend upon the opposite side, and be in- 

 serted into the prostate and opposite segment of the same ring. Two 



