196 URINARY ORGANS. 



and also by means of two rounded fibrous cords, the obliterated portions of the 

 hypogastric arteries, which are placed one on each side of the urachus. The 

 summit of the bladder behind the urachus is covered by peritoneum, whilst the 

 portion in front of the urachus has no peritoneal covering, but rests upon the 

 abdominal wall. 



The urachus is the obliterated remains of a tubular canal which exists in the 

 embryo, and connects the cavity of the bladder with a membranous sac placed 

 external to the abdomen, opposite the umbilicus, called the allantois. In the 

 infant, at birth, it is occasionally found pervious, so that the urine escapes at 

 the umbilicus, and calculi have been found in its canal. 



The body of ihe "bladder in front is not covered by peritoneum, and is in 

 relation with the triangular ligament of the urethra, the posterior surface of 

 the symphysis pubis, the Internal Obturator muscles, and, when distended, with 

 the abdominal parietes. 



The posterior surface is covered by peritoneum throughout. It corresponds, 

 in the male, with the rectum; in the female, with the uterus, some convolu- 

 tions of the small intestine being interposed. 



The side of the bladder is crossed obliquely from below, upwards and for- 

 wards, by the obliterated hypogastric artery ; above and behind this cord, the 

 bladder is covered by peritoneum ; but below and in front of it, the serous 

 covering is wanting, and it is connected to the pelvic fascia. The vas deferens 

 passes, in an arched direction, from before backwards, along the side of the 

 bladder, towards its base, crossing in its course the obliterated hypogastric 

 artery, and passing along the inner side of the ureter. 



The base (fundus) of the bladder is directed downwards and backwards. It 

 varies in extent according to the state of distension of the organ, being very 

 broad when full, but much narrower when empty. In the male, it rests upon 

 the second portion of the rectum, from which it is separated by a reflection of 

 the recto- vesical fascia. It is covered posteriorly, for a slight extent, by the 

 peritoneum, which is reflected from it upon the rectum, forming the recto- 

 vesical fold. The portion of the bladder in relation with the rectum corresponds 

 to a triangular space, bounded behind by the recto- vesical fold ; on either side, 

 by the vesicula seminalis and vas deferens; and touching the prostate gland in 

 front. When the bladder is very full, the peritoneal fold is raised with it, 

 and the distance between its reflection and the anus is about four inches; but 

 this distance is much diminished when the bladder is empty and contracted. 

 In the female, the base of the bladder lies in contact with the lower part of the 

 cervix uteri, is adherent to the anterior wall of the vagina, and separated from 

 the upper part of the anterior surface of the cervix uteri by a fold of the 

 peritoneum. 



The neck (cervix) of the bladder is the constricted portion continuous with 

 the urethra. In the male, its direction is oblique in the erect posture, and it is 

 surrounded by the prostate gland. In the female, its direction is obliquely 

 downwards and forwards. 



Ligaments. The bladder is retained in its place by ligaments, which are 

 divided into true and false. The true ligaments are live in number, two ante- 

 rior, and two lateral, formed by the recto-vesical fascia, and the urachus. The 

 false ligaments, also five in number, are formed by folds of the peritoneum. 



The anterior ligaments (pubo-prostatic) extend from the back of the pubes, 

 one on each side of the symphysis, to the front of the neck of the bladder, and 

 upper surface of the prostate gland. These ligaments contain a few muscular 

 fibres, prolonged from the bladder. 



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 attach- 

 ment to the bladder, and becomes narrower as it ascends. 



