1018 THE URIXARY ORGANS 



vesical pouch, a lower in direct contact witli the anterior wall of the rectum, and 

 the lower part of the vasa deferentia and vesicul» seminales. The distance of the 

 recto-vesical cul-de-sdc of i)eritoneum from tlie prostate is very variable, but usually 

 ranges between half an inch and one inch (12 to 25 nun.), and may be increased 

 to two inches (5 cm. ) Ijy distension of the bladder. It is, however, very small in 

 the child. The ureters where they lie at the outer limits of this surface are near to 

 though not in contact with the rectum, and a calculus in the lower end of the 

 urinary tube might l)e felt l\v an exploration from witliin the l)ow(l. In the lower 

 portion of the posterior wall in the male is a triangular space, the sides of Avhich 

 are formed by the diverging vasa deferentia, the base by the line of reflexion of the 

 recto-vesical pouch of peritoneum, and the apex by the meeting of the ejaculatory 

 ducts at the summit of the prostate. It was formerly selected as Xhe position for 

 the introduction of a trocar through the rectum into the bladder in cases of reten- 

 tion of urine. In the female the posterior surface is adherent below to the cervix 

 uteri and upper part of the anterior wall of the vagina, luit is separated above from 

 the body of tlu^ uterus l»y a shallow utero-vesical pouch of peritoneum. 



The superior surface is entirely covered with peritoneum. It looks almost 

 directly upwards into the abdominal cavity, and lies in contact with the small 

 intestines, and sometimes Avith a portion of the sigmoid colon behind these. 



Effects of distension. — When the bladder becomes excessively full it rises 

 above the level of tlie symphysis, and in certain chronic conditions of retention 

 may even mount as high as the umbilicus. During the process of distension the 

 anterior wall carries U})wards the peritoneal fold reflected on to its upper surface. 

 This elevation is, however, variable and limited in extent; at its maximum it 

 seldom exceeds two inches (5 cm.), and in some instances fails even to pass the 

 upper border of the symphysis, hence there is some danger in tapping the bladder 

 above the pubes, unless the part is exposed by a careful dissection. In recent 

 years Garson and Pietersen have demonstrated that the introduction into the 

 rectum of a bag of suitable dimensions filled Avith air or water pushes forward the 

 expanded viscus and may still further increase the available space for surgical 

 operation, but it does not ensure the elevation of the peritoneal fold aljove the 

 symphysis. 



The relation of the internal urinary meatus to the pelvic wall has become a 

 subject of interest since the revival of suprapuljic operations \x\)0\\ the bladder. As 

 a rule it lies at some point opposite the upper half of the symphysis, but in great 

 distension of the viscus (see Riidinger, plate 3) it may descend to a lower level. 

 On the other hand, in young children it usualh' reaches the level of the upper 

 border of the symphysis, and in old persons with prostatic disease it may rise even 

 above this point. In the male adult it lies from three-quarters of an inch to an 

 inch (2 cm. to 2.5 cm.) behind the symphysis, and about two or two and a half 

 inches (5 cm.) above the perinteum. 



Structure. — The bladder w^all is composed mainly of unstriped muscular fibre, 

 invested externally by a layer of recto-vesical fascia and a partial covering of 

 peritoneum, and lined with mucous membrane and submucous tissue. Its thick- 

 ness varies greatly in different subjects and in the same su])ject under dift'erent 

 conditions of distension. It is estimated at about an eighth of an inch when 

 moderately stretched, but may reach half an inch or even more when completely 

 contracted. It is somcAvhat thicker at the trigone. 



The arrangement of the peritoneum over the su])erior, lateral, and posterior 

 walls has l)een described, and it only remains to mention that its reflexions over 

 the urachus above, and from the sides and back of the bladder bt'low, form the 

 superior, lateral, and posterior false ligaments. The recto-vesical fascia is a 

 well-developed layer of tissue over the lower part of the viscus, but is greatly 

 attenuated above. It is continuous below Avith the capsule of the prostate, and 

 passes on to the pubic bones in front of the latter organ in tlie form of a doulile 

 fold called the pubo-prostatic or anterior true ligaments, and u]ion the IcA'ator 

 ani at the sides, Avhere its reflexions are termed the lateral true ligaments, while 

 the urachus aboA^e represents a superior ligament. These traditional names. 

 hoAA^ever, are misleading and haA'e no praeticnl value. The muscular coat is 

 composed of unstri])ed fibres, Avhich may be divicU'd n)Ughly into three layers, an 



