THE ABDOMEN 867 



bundle of muscular fibres, and is slightly convex, with the con- 

 vexity directed downwards towards the urethral orifice. The 

 urethro-ureteric ridge on either side is also produced by a bundle of 

 muscular fibres, these bundles being known as the muscles of Bell. 

 The uvula vesicae is situated at the lower part of the trigone 

 in the middle line, above the urethral orifice. 



Lumen of the Empty Bladder. — ^This is very small, and is com- 

 posed of two limbs, anterior and posterior. The anterior limb, 

 which is long, lies almost horizontally in front of the urethral 

 orifice, and is formed by the juxtaposition of the superior and 

 inferior walls. The posterior limb, which is short, is directed 

 upwards and backwards, and is formed by the juxtaposition of 

 the back part of the superior wall and the base. The anterior and 

 posterior limbs join each other at the urethrcd orifice, and are 

 there continued onwards into the lumen of the prostatic urethra. 

 A triradiate appearance is thus imparted to the lumen of the 

 empty bladder and of the prostatic urethra, the three rays diverg- 

 ing from a central point, namely, the urethral orifice, one ray being 

 urethral, and two vesical, of which latter one is the anterior limb 

 of the vesical lumen, and the other the posterior limb. 



The Infantile Bladder. — The bladder in early life is pyriform. 

 The narrow end is directed downwards, and is on a level with the 

 upper border of the symphysis pubis, from which point it gradually 

 descends as age advances. The broad end is directed upwards, 

 and hes in the hypogastric region of the abdomen. The base is 

 absent at this period, and the anterior surface of the viscus, devoid 

 of peritonemn, is in contact with the posterior surface of the anterior 

 wall of the abdomen, which is likewise destitute of peritoneum. 

 There being no base, the bottom of the recto-vesical pouch of 

 peritoneum lies close to the base of the prostate gland. 



Ligaments of the Bladder. — These are arranged as false and true 

 ligaments. The false ligaments are formed by the peritoneum, 

 and are five in number, as follows : two posterior, which represent 

 the laterally-disposed lips of the mouth of the recto-vesical pouch ; 

 two lateral, right and left, which represent the reflection of the 

 peritoneum from each lateral border of the bladder to the corre- 

 sponding lateral wall of the pelvis ; and superior, which is the 

 reflection of the peritoneum from the apex o^ the bladder to 

 the posterior surface of the anterior abdominal wall along the 

 urachus. The true ligaments are also five in number, as follows : 

 two lateral, right and left, which are formed by the vesical layers 

 of the visceral portion of the pelvic fascia on the sides of the 

 bladder ; two anterior or pubo -pro static, which are the reflections 

 of the visceral pelvic fascia from the back of the bodies of the 

 pubic bones near the lower part of the symphysis to the neck of 

 the bladder, and which pass in their course over the anterior surface 

 of the prostate gland ; and superior, which is the urachus. Each 

 anterior true ligament contains some of the external or longitudinal 

 muscular fibres of the bladder. 



