438 



ABDOMEN 



with the peritoneum both in front and on the sides ; then the 

 peritoneum passes away from the sides, so that in its middle 

 third the gut is covered merely in front ; finally, about an 

 inch above the base of the prostate, at the bottom of the 

 recto -vesical excavation, the membrane quits the rectum 

 altogether, and is reflected on to the deferent ducts and the 



Superior haemorrhoidal vessels 



Processus vermiformis 



Umbilical 

 artery 



Obt. vessels 

 and nerve 



Ureter / 



Pelvic plexus of sympathetic 



nerves and haemorrhoidal 



veins 



Root of pelvic 

 meso-colon 



Lower end of 

 pelvic colon 



Internal 

 --spermatic 



Genito-femoral 

 x nerve 



External iliac 



vessels 



Umbilical art 

 Obturator nen 

 Obturator ve 

 Ureter 



Pelvic plexus 



sympathetic 



nerves 



Rectum 



M. levator ani 



M. levator ani 



Anal canal 



M. sphincter ani externus 



FIG. 205. Dissection of the Rectum from the front in a specimen hardenec 

 by formalin injection. The anterior wall of the pelvis has been removed, 

 and the bladder, prostate, and seminal vesicles have been taken away. 



seminal vesicles, as they lie at the fundus of the bladder. 

 The lower third of the rectum is thus altogether devoid of 

 peritoneum. It is separated from the fundus of the bladder 

 and the posterior surface of the prostate by the recto-vesical 

 layer of pelvic fascia; and embedded in the fascia, behind 

 the bladder, are the lower parts of the deferent ducts and 

 the seminal vesicles. 



On each side of the upper part of the undistended rectum 



