THE NERVOUS SYSTEM 22/ 



matic cord, scrotum, and the integument of the upper 

 thigh. 



The genitocrural nerve arises from the second lumbar, 

 enters the muscles of the anterior part of the thigh, and 

 descends to near Poupart's ligament, where it divides into 

 the genital and crural branches. The genital gives off 

 branches to the internal abdominal ring and to the genital 

 organs of the female; at the internal abdominal ring it 

 sends off branches to the internal oblique and transversalis 

 muscles, and is lost in the integument of the groin. The 

 crural branch, the most external, descends along the outer 

 border of the external iliac artery, and enters the sheath 

 of the femoral artery ; it is distributed to the upper as well 

 as the anterior aspect of the thigh, communicating with 

 the middle cutaneous nerve. 



The external cutaneous nerve arises from the second 

 lumbar nerve, or from a loop between it and the third; it 

 passes into the thigh, beneath Poupart's ligament, where 

 it divides into two branches the posterior and the an- 

 terior, the posterior furnishing branches to the tensor 

 vaginae f emoris muscle and posterior part of the thigh ; the 

 anterior divides into several branches, which are distrib- 

 uted to the outer border of the thigh and knee. 



The obturator is formed from the third and fourth lum- 

 bar nerves. It makes a distribution to the obturator 

 muscles, femoral and popliteal arteries, knee-joint, hip, 

 and integuments of the upper and inner part of the thigh. 

 At its origin it courses along the common iliac until it 

 reaches the pelvic brim, where it passes through the 

 obturator foramen and joins, in its course, the obturator 

 artery; having escaped from the pelvis, it divides into 

 anterior, posterior, and accessory branches, which supply 

 the several muscular structures of the lower extremity. 



The anterior crural nerve, sometimes called the femoral 

 nerve, is the largest branch of the lumbar plexus; it is 



