204 ABDOMEN 



to it by early and free incisions, it will continue to ascend 

 over the abdomen between the superficial and the deep 

 fascia. 



Nervi Cutanei. The cutaneous nerves of the anterior 

 and lateral walls of the abdomen are arranged, in an anterior 

 and a lateral series, on the same plan as the cutaneous nerves 

 of the thorax (p. 5). 



(i. Anterior cutaneous nerves. 



2. Anterior cutaneous branch of the ilio - hypogastric 



3. The ilio-inguinal nerve. 



(I. Lateral cutaneous nerves. 



2. Lateral cutaneous branch of the last thoracic nerve. 



3. Lateral cutaneous branch of ilio-hypogastric nerve. 



The anterior cutaneous nerves are the small terminal twigs 

 of the lower five or six thoracic nerves. They pierce the 

 aponeurotic sheath of the rectus muscle at variable points, 

 some close to the median line and others a little distance 

 from it. After entering the superficial fascia they run for a 

 short distance laterally. 



Dissection. To display the anterior cutaneous nerves divide 

 the superficial fascia along the middle line, and reflect it cautiously 

 towards each side. Small arteries accompany the nerves, and 

 serve as guides to their positions. 



The anterior cutaneous branch of the ilio-hypogastric lies 

 in series with the other anterior cutaneous nerves. When 

 the superficial fascia was dissected it was seen piercing the 

 aponeurosis of the external oblique a short distance above the 

 subcutaneous inguinal ring. 



The ilio-inguinal nerve passes out through the subcutaneous 

 inguinal ring, and is distributed to the integument of the 

 scrotum, or the labium majus, and the medial aspect of the 

 thigh. 



Dissection. To display the lateral cutaneous nerves cut 

 through the superficial fascia, along the posterior axillary line, 

 from the upper part of the abdominal wall to the iliac crest ; 

 then reflect the anterior part of the divided fascia forwards and 

 medially and secure the nerves as they emerge from between 

 the digitations of the external oblique muscle. Each nerve 

 divides into an anterior and a posterior branch. The anterior 

 branches give twigs to the external oblique, and may be followed 

 to the linea semilunaris. The posterior branches should be 

 followed backwards over the lateral border of the latissimus 

 dorsi. 



The lateral cutaneous nerves are branches of the lower six 



