566 



ANATOMY IN A NUTSHELL. 



spongiosum. This fascia and the dartos aided by the Bulbo cavernosi and the 

 [schio-cavernosi muscles compress the veins of the penis in the action of erec- 

 tion. 



Blood Supply.— The arteries to the penis are branches of the internal 

 pudic. (a) The artery of the bulb, which goes to the bulb of the corpus spon- 

 giosum, (hi the arteries of the corpora cavernosa, (c) the dorsal artery of the 

 penis. The envelops of the penis are supplied by the external pudic, the 

 superficial perineal, and the dorsal artery. The veins of the penis are in two 

 sets, (a) superficial veins, which pass between the dartos and fascial sheath 

 end in the long saphenous and femoral veins, (b) the deep veins, which drain 

 the corpora cavernosa, corpus spongiosum, end in the deep dorsal vein and in 

 the internal pudic vein. 



Lymphatics of the penis are divided into two sets, (a) superficial ones 

 which pass to the inguinal nodes, and (b) deep ones which empty into the pelvic 

 and Lumbar nodes as well as in the inguinal nodes. 



Nerve Supply. — The genital branch of the genito-crural and the super- 

 ficial perineal branches of the pudic supply the covering of the penis, while the 

 dorsal nerve of the penis, and superficial perineal, and hypogastric plexus sup- 

 ply the erectile bodies. 



PLATE CCLXXXVI. 



SEMICIRCULAR CANAL 



5CALA TYMPANI INFERIOR 



Interior of Bony Labyrinth. 



The spermatic cord is about four inches long and extends from the internal 

 abdominal ring to the globus minor of the epididymis. It passes through the 

 inguinal canal. It is composed of the following structures held together by 

 areolar tissue and invested by layers broughl down by the descent of the testicle. 



1. The vas deferens, which is the excretory duct of the testicle passing 

 from the testis to the ejaculatory dud. It is recognizable by its cord-like 

 resistance to pressure. 



_'. The artery of the vas deferens, which is a branch of the superior vesical 

 artery. It arises from this artery near the place where the vas deferens crosses 

 the obliterated hypogastric artery, and it divides into an ascending branch 

 which follows the vas deferens through the inguinal canal, and a descending- 

 branch which passes n> the dilated poll ion of the vas deferens and the vesicula 

 seminalis. 



:!. The cremasteric artery, which is a branch of the dee]) epigastric, passes 



