221 



XXI spinal N 



more direct course than the inguinal, passing through the psoas muscle 

 and thence to Poupart's ligament. The genital nerve passes through 

 the abdominal wall above Poupart's ligament to enter the inguinal 

 canal, fuse with the inguinal nerve and aid this in its supply. The 

 inguinal and genital nerves vary inversely in size. The crural nerve 

 passes below the ligament and supplies the skin of the upper anterior 

 part of the thigh. 

 The genito - crural 

 nerves may be bound 

 up for a part of 

 their course into a 

 single trunk or they 

 may be multiple in 

 number. Their vari- 

 ation in course and 

 distribution is great. 

 Often they carry 

 motor fibres to the 

 abdominal muscula- 

 ture and small nerve 

 bundles for the fe- 

 moral artery. The 



lateral cuta- 

 neous nerve runs 

 usually to a point 

 shghtly below the 



anterior superior 

 iliac spine where it 

 passes under Pou- 

 part's ligament to 

 the thigh. 



Anastomotic 

 branches are com- 

 mon between the 

 border nerves and 

 between these and the true abdominal nerves on the one hand and 

 the lateral cutaneous nerve (and middle cutaneous branches of the 

 femoral nerve also) on the other. 



In tables 2 — 8 the origin of the nerves we have just been con- 

 sidering from the spinal nerves is shown. This is also illustrated in 

 figures 2—8. In the most anterior type of plexus (A), table 2, 



Fig. 3. Plexus of type B. 



