SURGICAL ANATOMY. 381 



The internal abdominal ring is an oval opening in the 

 transversalis fascia about half an inch above Poupart's ligament, 

 midway between the symphysis pubis and the anterior superior 

 spinous process of the ilium. It is bounded 



Above and externally by the arched fibres of the transversalis 

 muscle ; below and internally by the deep epigastric vessels. 



It transmits a funnel-shaped fascia from its margins, the 

 infundibuliform fascia. 



The external abdominal ring is a triangular opening between 

 the two pillars in the aponeurosis of the external oblique muscle, 

 to the outer side and just above the spine of the pubes. It is 

 about half an inch wide and one inch long, and is bounded- 

 Above, by the intercolumnar fascia ; below, by the spine and 

 crest of the os pubis, and on either side by the pillars or columns 

 of the ring formed by the free margins of the aponeurosis of 

 the external oblique. 



From the margins of the external abdominal ring arises the 

 intercolumnar fascia. 



Poupart's ligament, or the femoral arch, is the rounded 

 lower fibrous margin of the external oblique muscle, extending 

 between the anterior superior spine of the ilium and the spine 

 of the pubes. The portion of the aponeurosis which is inserted 

 into the pectineal line has received the name of Gimbernat's 

 ligament. 



The epigastric artery holds a very important anatomical 

 relation to the inguinal canal and internal abdominal ring. It 

 ascends between the peritoneum and transversalis fascia to reach 

 the sheath of the rectus muscle along the inner and lower margin 

 of the internal ring and beneath the spermatic cord. 



The coverings of oblique inguinal hernia are: 



1. Skin; 



2. Superficial fascia; 



3. Intercolumnar fascia; 



4. Cremaster muscle; 



5. Fascia transversalis, or infundibuliform fascia; 



6. Subserous connective tissue; 



7. Peritoneal sac. 



2. DIRECT INGUINAL HERNIA escapes through the abdominal 

 wall, within Hesselbach's triangle, internal to the epigastric 

 artery, and through the external abdominal ring, pushing before 

 it a pouch of peritoneum. 



Hesselback's triangle is a space situated at the lower ante- 

 rior part of the abdominal wall on either side. It is bounded 

 as follows: 



Externally, epigastric artery; 



