452 ABDOMEN 



At the abdominal inguinal ring it separates from the other 

 constituents of the spermatic cord, hooks, medially, round the 

 inferior epigastric artery, and descends on the medial side of 

 the external iliac vessels into the pelvis minor. It then runs 

 backwards, on the side wall of the pelvis, immediately external 

 to the peritoneum, through which it is clearly visible, and it 

 crosses, in turn, the umbilical artery, the obturator nerve, the 

 superior vesical artery, and the ureter. Immediately beyond 

 the ureter it turns sharply medially towards the fundus of the 

 bladder, enters the pelvic fascia, comes into relation with the 

 blunt, upper end of the seminal vesicle, and runs downwards 

 and medialwards, in close apposition with the upper or medial 

 side of the vesicle, to the base of the bladder. There, lying 

 close to the median plane, and to its fellow of the opposite 

 side, it turns vertically downwards to the base of the prostate. 

 The lower part of the duct is dilated, tortuous, and sacculated, 

 and is termed the ampulla^ but its lower end narrows greatly 

 and joins with the duct of the seminal vesicle to form the 

 ejaculatory duct. 



Ductus Ejaculatorius. The ejaculatory duct is formed, 

 immediately above the base of the prostate, by the union of 

 the excretory duct of the seminal vesicle with the termination 

 of the ductus deferens. Its walls are thin and delicate ; it is 

 therefore easily torn. Its length is about 18.6 mm. (three- 

 quarters of an inch), and it descends, through the substance 

 of the prostate between the middle and lateral lobes, to the 

 corresponding margin of the opening of the prostatic utricle, 

 where it opens into the prostatic part of the urethra. 



Triangle on the Base of the Bladder. It is customary 

 to describe a triangle at the base of the bladder, bounded 

 laterally by the deferent ducts, and above by the reflection of 

 the peritoneum at the bottom of the recto-vesical excavation. 

 When the pelvic viscera are hardened in situ, by formalin 

 injection, such a space can hardly be said to exist, owing to 

 the approximation of the ampullae of the deferent ducts, 

 but it is possible that when the bladder is distended the 

 space between the deferent ducts may be increased. 



Dissection. The peritoneum has already been lifted up and 

 the extraperitoneal fat removed to show the visceral branches 

 of the hypogastric artery. The pelvic fascia must now be 

 removed and the remaining branches of the hypogastric artery 

 and the accompanying veins must be followed, so far as they lie 

 in the pelvis. Accompanying the arteries a number of nerve 



