296 Anatomy Applied to Medicine and Surgery. 



ing the vas deferens, may cause reflex contraction of the 

 cremaster muscle through stimulation of the genito-crural 

 which supplies this muscle, so that retraction of the tes- 

 ticle would result. Where the pain is felt in the penis, it 

 is due to projection, or reference of the irritation from that 

 portion of the hypogastric plexus which supplies the blad- 

 der, i.e., the vesical plexus, to the cavernous plexus or 

 nerve, which is distributed to the penis. 



Stricture of the urethra may cause priapism from the 

 fact that the urethra itself as well as the muscles of the 

 penis are all supplied by the same nerve, viz., by the in- 

 ternal pudic, and hence irritation of the mucous mem- 

 brane of the urethra may reflexly cause erection of the 

 the penis through stimulation of the erector muscle, since 

 both mucous membrane and muscles are controlled by the 

 one nerve, and for the same reason, the passage of a sound 

 may cause spasmodic stricture, owing to reflex contrac- 

 tion of the compressor urethrae muscle. Injury to the 

 testicle may cause shock or collapse, just as a similar injury 

 to the intestine would, since both testicle and intestine re- 

 ceive their nervous supply from the solar plexus the tes- 

 ticle receiving its supply through the spermatic plexus, an 

 offset from the renal and aortic plexuses, which are de- 

 rived from the solar plexus. The ovary has a somewhat 

 similar nervous connection through the ovarian plexus, 

 with the result, that disease of this organ may cause re- 

 flex symptoms through the widespread connection of the 

 solar plexus, already referred to, when dealing with the 

 nervous reflexes of the intestine. 



Operations. Ischio-rectal abscess should be open- 

 ed early, since the blood supply of this region is very poor 

 and suppurative processes rapidly spread and open, either 

 externally, through the skin, or internally, into the rectum, 

 forming what is known as "fistula in ano." In opening 



