226 VISCERAL ANATOMY. 



HERNIA. 



What is a Hernia ? A protrusion of any viscus from its natural cavity. 

 The term, when unqualified as to the viscus, is understood to mean a protru- 

 sion of the intestines or mesentery, or both, from the abdominal cavity. 



Name the Herniae of most importance anatomically. 

 Oblique Inguinal Hernia, in which the protrusion follows the spermatic 



cord through the inguinal canal ; passing to the outer side of the epigastric 



artery, and through both the internal and external abdominal rings. 

 Direct Inguinal Hernia, occurs at Hesselbach's triangle, escaping to the 



inner side of the epigastric artery, and through the external abdominal ring 



only. 

 Femoral Hernia, in which the protrusion descends through the femoral or 



crural canal. 



INGUINAL HERNIA. 



Where is the Inguinal Canal ? It is a passage in the abdominal wall, 

 parallel to Poupart's ligament, and just above it. It commences at the internal 

 abdominal ring 5 and ends at the external abdominal ring, 1 being about i^ 

 inch in length. It serves for the passage of the spermatic cord in the male, 

 and the roundj ligament of the uterus in the female ; and is directed down- 

 wards and inwards. The 



Internal Abdominal Ring, 5 is an oval opening in the transversalis fascia, 

 formed by the prolongation of this fascia around the cord, as the infundi- 

 buliform fascia. It lies % inch above Poupart's ligament and midway 

 between the anterior superior spine of the ilium and the spine of the 

 pubes. It is bounded above and externally by the arched fibres of the 

 transversalis muscle; below and internally by the epigastric vessels. 

 External Abdominal Ring, 1 is a triangular opening in the aponeurosis 

 of the external oblique muscle, situated just above and external to the 

 crest of the pubes. It is about I inch long, and y^ inch wide, and is 

 bounded laterally by its own margins, called the Internal 4 and Exter- 

 nal 3 Pillars of the ring. From these margins is given off the Inter- 

 columnar Fascia, around the cord and testis. 



What are the Boundaries of the Inguinal Canal ? 

 Anteriorly, the Skin, Superficial fascia, External oblique muscle, and the 



Internal oblique for its outer one-third. 

 Posteriorly, the Conjoined tendon, Transversalis fascia, Triangular ligament, 



Sub- peritoneal tissue, and Peritoneum. 



Above, the arched fibres of the Internal oblique and Transversalis muscles. 

 Below, Poupart's ligament, and the Transversalis fascia. 



