CRURAL NERVE BRANCHES. 417 



of the ilium, and divides into two branches, anterior and posterior. 

 The posterior branch crosses the tensor vaginae femoris muscle to 

 the outer and posterior side of the thigh, and supplies the integu- 

 ment in that region. The anterior nerve divides into two branches 

 which are distributed to the integument upon the outer border of 

 the thigh, and to the articulation of the knee. 



The Genito-crural proceeds also from the second lumbar nerve. 

 It traverses the psoas magnus from behind forwards, and 'runs 

 down on the anterior surface of that muscle and beneath its fascia 

 to near Poupart's ligament, where it divides into a genital and a 

 crural branch. The genital branch crosses the external iliac artery 

 to the internal abdominal ring and descends along the spermatic 

 canal, lying behind the cord to the scrotum, where it divides into 

 branches which supply the spermatic cord and cremaster in the male, 

 and the round ligament in the female. At the internal abdominal 

 ring this nerve sends some filaments to the lower border of the inter- 

 nal oblique and transversalis muscle. The crural branch enters the 

 sheath of the femoral vessels in front of the femoral artery. It 

 pierces the sheath below Poupart's ligament, and is distributed to 

 the integument of the anterior aspect of the thigh as far as its middle. 

 This nerve often communicates with a cutaneous branch of the 

 crural nerve in the thigh. 



The CRURAL, or FEMORAL NERVE, is the largest of the divisions 

 of the lumbar plexus ; it is formed by the union of the branches from 

 the second, third, and fourth lumbar nerves, and, emerging from 

 beneath the psoas muscle, passes downwards in the groove between 

 it and the iliacus, and beneath Poupart's ligament into the thigh, 

 where it spreads out and divides into numerous branches. At Pou- 

 part's ligament it is separated from the femoral artery by the breadth 

 of the psoas muscle, which at this point is scarcely more than half 

 an inch in diameter, and by the iliac fascia, beneath which it lies. 



Branches. While situated within the pelvis the crural nerve 

 gives off several muscular branches to the iliacus and psoas. On 

 emerging from beneath Poupart's ligament the nerve becomes flat- 

 tened and divides into* numerous branches, which may be arranged 

 into, 



Cutaneous, 



Muscular, 



Branch to the femoral sheath, 



Short saphenous nerve, 



Long saphenous nerve. 



The Cutaneous branches are four or five in number ; they pierce 

 the fascia lata at irregular distances below Poupart's ligament, and 

 are distributed to the integument on the front and inner side of the 

 thigh, constituting the middle and internal cutaneous nerves. Two 

 of these nerves pass through the sartorius muscle before becoming 

 cutaneous. 



53 



