CUTANEOUS NERVES. 



263 



posterior. As soon as they reach the surface they divide, with the whlch 



J / . divide into 



exception of the last, into an anterior and a posterior branch : 



The posterior branches are small, and are directed back to the posterior 

 integuments over the latissimus dorsi muscle. 



The anterior branches are continued forwards nearly to the edge of anterior 

 the rectus muscle, and increasing in size from above downwards, 

 supply the integuments on the side of the belly ; they furnish offsets 

 to the digitations of the external oblique muscle. 



The lateral cutaneous branch of the last dorsal nerve is larger than Last dorsal 

 the others and does not divide like them. After piercing the fibres of nerve - 



Anterior cutaneous 

 nerves coming 

 through the sheath of 

 the rectus abdominis. 



Lateral cutaneous nerves. 



Inner pillar of ex- 

 ternal abdominal ring. 



Outer pillar of ex- 

 ternal abdominal ring- 



External oblique. 



Linea semilunaris. 

 Linea alba. 



Anterior superior 

 iliac spine. 



Poupart's ligament. 



Deep crural arch. 

 Gimbernat's liga- 

 ment. 

 Triangular fascia. 



FIG. 97. DIAGRAM OF THE CUTANEOUS NERVES OF THE ABDOMEN AKD OF 

 THE EXTERNAL OBLIQUE MUSCLE. 



the external oblique muscle, it is directed over the iliac crest to the 

 surface of the gluteal region (p. 110). 



The ANTERIOR CUTANEOUS NERVES of the abdomen pierce the 

 sheath of the rectus ; in the integuments they bend outwards towards 

 the lateral cutaneous nerves. The number and the situation of 

 these small nerves are very uncertain. 



The ILIO-HYPOGASTRIC NERVE is distributed in two branches : one 

 passes over the crest of the ilium (iliac branch) ; the other ramifies 

 on the lower part of the abdomen (hypogastric branch) : 



(a) The iliac branch lies close to the crest of the hip-bone near the 

 last dorsal nerve, and enters the fat of the gluteal region (p. 110). 



Anterior 

 cutaneous 

 nerves of 

 intercostal. 



Ilio-hypo- 

 gastric of 

 lumbar 

 plexus : 



iliac branch. 



