378 THE GENITO-URINARY SYSTEM 



Both the ductus deferentes and the seminal vesicles can be 

 palpated through the anterior wall of the rectal ampulla (p. 

 283), but it is only when they are thickened by inflammatory 

 processes that they can be made out with certainty. 



Very little is known about the nerve-supply of these 

 structures, but, since the ureter arises from the distal portion 

 of the Wolffian duct (p. 380), the nerve-supply of the ductus 

 deferens, which represents the persistent Wolffian duct (p. 

 380), must, in its terminal part at least, correspond to the 



Cut edge of peritoneum 



!Z^A. 



'-Ureter 



- Ductus deferens 



- Seminal vesicle 



Infero-lateral 

 """ surface of bladder 



Ejaculatory duct 



Prostate 



FIG. 132. The Urinary Bladder and the Prostate, viewed from behind. 



nerve-supply of the ureter. The rest of the Wolffian duct 

 arises in the abdomen, and it would appear likely that several 

 segments above the first lumbar take part in the innerva- 

 tion of the ductus deferens. Referred pains in connexion with 

 these structures have not yet been sufficiently studied. 



The Urethra begins at the internal orifice at the neck 

 of the bladder and passes downwards and forwards through 

 the prostate. At the apex of the prostate, it pierces the uro- 

 genital diaphragm and then enters the bulb of the penis, in 

 which it passes upwards and forwards to the corpus cavernosum 



