442 



ABDOMEN 



abdominal wall, to the umbilicus. The urachus is the re- 

 mains of the cephalic part of the ventral section of the cloaca 

 of the embryo. 



The superior surface looks upwards and backwards, and is 

 completely covered with peritoneum. It supports some coils 

 of small intestine and, not uncommonly, a coil of the pelvic 

 colon. It is slightly convex ; it is triangular in outline, and 

 is bounded by three borders, viz. two lateral, which diverge 

 from the apex, and a posterior, which separates it from the 

 base. The lateral and posterior borders meet at the posterior 

 angles, and at those angles the ureters enter the bladder wall. 



Ureter 



Seminal 

 vesicle 



Prostate 



Middle 

 umbilical 

 ligament 



Infero-lateral surface 

 Membranous urethra 



FIG. 209. Bladder, hardened in situ, viewed from the right side. It 

 contained a slightly larger amount of fluid than the specimen depicted in 

 Fig. 207. (A. F. Dixon.) 



Each lateral border is in relation with the side-wall of the 

 pelvis, along a line considerably below the level of the deferent 

 ducts and the umbilical artery. 



The infero-lateral surfaces are separated from each other 

 by a rounded, anterior border. Each infero-lateral surface 

 forms part of the posterior wall of the cave of Retzius, 

 and is separated by extra-peritoneal fat from the back of the 

 body of the pubic bone and the fascia covering the pelvic 

 surfaces of the corresponding obturator internus and the 

 levator ani muscles. 



The anterior border, which separates the infero-lateral sur- 

 faces, lies behind the symphysis and above and in front of the 

 prostate. It extends downwards and backwards to the internal 



