THE PERIPHERAL NERYOUS SYSTEM. 397 



and fifth nerves, most of its fibres coming from the fifth. It 

 passes caudoventrad between the iliopsoas and psoas minor and 

 accompanies the iliolumbar artery across the ventral surface of 

 the iliopsoas. It pierces the abdominal wall in company with 

 the artery and passes onto the cranial border of the thigh. Its 

 terminal branches are distributed to the integument along with 

 the branches of the iliolumbar artery, supplying the lateral 

 surface of the femur and extending as far as the knee. 



6. N. femoralis (_/). The femoral is a large nerve which 

 rises by strong roots from the fifth and sixth lumbar nerves. 

 It gives branches to the iliopsoas (s) and passes through that 

 muscle to its ventral surface. It leaves the abdominal cavity 

 lying on the ventral surface of the iliopsoas, and at the point 

 where it pierces the abdominal wall it divides into three (or 

 four) branches. One (or two) of these pass to the sartorius 

 muscle. Another passes between the rectus femoris and vastus 

 medialis muscles, and divides into numerous branches which 

 supply these muscles and the vastus intermedius. 



The third branch of the femoral is N. saphenus or the long 

 saphenous nerve (Fig. 127, g, page 310). This passes distad 

 along with the femoral artery and vein, giving a few twigs to 

 the integument. Where the long saphenous artery (_/") sep- 

 arates from the femoral artery the nerve follows the former and 

 passes with it along the medial side of the lower leg. At the 

 knee and in the lower leg it gives off a number of cutaneous 

 branches, and finally divides just distad of the middle of the 

 lower leg into two main branches. Both of these pass to the 

 concavity of the ankle-joint and divide into fine branches, which 

 form a sort of plexus on the ankle and dorsal surface of the 

 foot; branches from this can be traced almost to the toes. 



7. N. obturatorius (Fig. 162, g). The obturator nerve 

 arises from the connecting band between the sixth and seventh 

 nerves. It lies at first laterad, then dorsad, of the common 

 iliac vein, and passes almost directly caudad to the cranial 

 border of M. obturator internus (15). Here it turns sharply 

 laterad about the pubis, and passes through the obturator 

 foramen. It gives twigs to the obturator externus muscle, and 



