ABDOMEN. 



235 



same kind of investments. As before stated, these coats are simply certain parts 

 of the walls which have receded before the hernia in its descent. 



Describe tJic ilio-liypogastric nerve. 



It is a branch of the lumbar plexus. It is known also as the superior mus- 

 culo-cutaneous nerve. It crosses the quadratus lumborum muscle, gains the 

 space between the transversalis and internal oblique muscles, and divides into (i) 

 an iliac branch, which supplies the skin over the gluteal region ; (2) a terminal 

 hypogastric branch, that passes between these two muscles i. c\, the internal 

 oblique and transversalis to near the mid-line, where it comes through the 

 abdominal walls an inch above the external abdominal ring. 



Describe the ilio-inguinal nerve. 



You find this nerve anterior to the spermatic cord. It is distributed to the 



Epigastric artery 



Internal abdom- 

 inal ring 



Border of the 

 posterior part 

 of the sheath 

 of the reetus 

 (fold of Doug- 

 las) 



Posterior surface 

 of reetus 



'Jjitf Conjoined tendon 



in the triangle 



of Hesselbach 

 Obliterated hypo- 

 gastric artery 

 Lymphatics in 

 crural rings 



External iliac artery 



FIG. 164. DISSECTION OF THE LOWER PART OF THE ABDOMINAL WALL FROM WITHIN, THE PERI- 

 TONEUM HAVING BEEN REMOVED. (Wood.) 



scrotum and labia majora, and to the inner and upper part of the thigh. It is a 

 branch of the lumbar plexus. It runs near to and plexifies with the preceding 

 nerve, between the internal oblique and transversalis. 



Describe t/te genilo-crural nerve. 



This is seen behind the spermatic cord, in the canal ; after the cord emerges 

 from the external abdominal ring, the genital branch of the genito-crural nerve is 

 seen behind the cord. This supplies the cremaster muscle with motion. The 

 crural branch of the genito-crural nerve goes to the skin over the mid-front of 

 the thigh half way to the knee. 



INTERIOR VIEW OF ABDOMINAL WALLS. 



Make an incision on each side, from the lower part of the umbilicus to the 

 anterior superior spine of the ilium, through the entire remaining abdominal wall. 

 Turn the V-shaped flap thus formed forward, and at the same time lift it upward 



