730 URINARY ORGANS. 



convex behind than in front. In the female, it is larger in the transverse than 

 in the vertical diameter, and its capacity is said to be greater than in the male. 

 "When moderately distended, it measures about five inches in length, and three 

 inches across, and the ordinary amount which it contains is about a pint. 



The bladder is divided into a summit, body, base, and neck. 



The summit or apex of the bladder is rounded and directed forwards and 

 upwards ; it is connected to the umbilicus by a fibro-muscular cord, the urachus. 

 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 is Uncovered by it, and rests upon the abdominal wall. 



The urachus is the obliterated remains of a tubular canal existing in the embryo, 

 which 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 the 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 convolutions of 

 the small intestine being interposed. 



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

 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 or 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 peri- 

 toneum, 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, in front, by the prostate gland. 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 cervix or neck 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 down- 

 wards and forwards. 



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

 into true and false. The true ligaments are five in number, two anterior 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. 



