250 INGUINAL HERNIA. 



portion of the parietes from the frequent occurrence of direct in- 

 guinal hernia. 



INGUINAL HERNIA. 



Inguinal hernia is of two kinds, oblique, and direct. 



In oblique inguinal hernia the intestine escapes from the cavity 

 of the abdomen into the spermatic canal, through the internal abdo- 

 minal ring, pressing before it a pouch of peritoneum which consti- 

 tutes the hernial sac, and distending the infundibiliforin process of 

 the transversalis fascia. After emerging through the internal abdo- 

 minal ring, it passes first beneath the lower and arched border of 

 the transversalis muscle ; then beneath the lower border of the in- 

 ternal oblique muscle ; and finally through the external abdominal 

 ring in the aponeurosis of the external oblique. From the trans- 

 versalis muscle it receives no investment ; while passing beneath the 

 lower border of the internal oblique it obtains the cremaster muscle; 

 and, upon escaping at the external abdominal ring, receives the in- 

 tercolumnar fascia. So that the coverings of an oblique inguinal 

 hernia, after it has emerged through the external abdominal ring, 

 are, from the surface to the intestine, the 



Integument, 



Superficial fascia, 



Intercolumnar fascia, 



Cremaster muscle, 



Transversalis, or infundibiliform fascia, 



Peritoneal sac. 



The spermatic canal, which, in the normal condition of the abdo- 

 minal parietes serves for the passage of the spermatic cord in the 

 male, and the round ligament with its vessels in the female, is about 

 one inch and a half in length. It is bounded in front by the aponeu- 

 rosis of the external oblique muscle ; behind by the transversalis 

 fascia, and by the conjoined tendon of the internal oblique and trans- 

 versalis muscle ; above by the arched borders of the internal oblique 

 and transversalis ; below by the grooved border of Poupart's liga- 

 ment ; and at each extremity by one of the abdominal rings, the in- 

 ternal ring at the inner termination, the external ring at the outer 

 extremity. These relations may be more distinctly illustrated by 

 the following plan 



Above. 

 Lower borders of internal oblique 



and transversalis muscle. 

 In Front. Behind. 



Transversalis fascia. Con- 



Aponeurosis of external 

 oblique. 



Spermatic canal. 



joined lendon of internal 

 oblique and transversalis. 



Below. 



Grooved border of 

 Poupart's ligament. 



