166 



LUMBAR NERVES. 



the two heads of the pronator teres muscle, and descending the fore- 

 arm, between the flexor sublimis and profundus muscles, it is dis- 

 tributed to the fingers, with the exception of those supplied by 

 the ulnar. 



DORSAL NERVES. 



These are twelve in number; the anterior branches are the 

 larger, and received into the intercostal grooves, in which they run, 

 to be distributed to the muscles of the chest. 



The^/-5^ dorsal nerve pins the brachial plexus. The intercosto- 

 humcral nerves^ are two in number, and proceed from the second 

 and third dorsal nerves to be distributed upon the skin and fascia of 

 the arm ; the larger is sometimes called the nerve of Wrisberg. 



LUMBAR NERVES. 



These are five in number ; the anterior branches descending form 

 the lumbar plexus, which is situated upon the qwadratus lumborum 

 muscle and behind the psoas magnus muscle ; from it are given off 

 two or three abdomino-crural\ branches, which supply the muscles 



of the abdomen, sending 

 Fig. 144. a filament to the groin. 



The external cutaneous'^ 

 crosses obliquely the ilia- 

 cus internus muscle, to- 

 wards the anterior supe- 

 rior spinous process. It 

 perforates the fascia lata, 

 and is distributed to the 

 integuments of the thigh. 

 The extcryial sjDermatic^ 

 perforates the psoas mus- 

 cle, and descending to the 

 groin, supplies the glands 

 and cremaster muscle. 

 The anterior crural,^ 

 the largest branch of the 

 lumbar plexus, passes 

 under Poupart's ligament, 

 and gives off the anterior, 

 middle, and internal 

 cutaneous branches,'' ^^ 

 which are distributed to 

 the integuments ; the long 

 or internal saphenous 

 nerve, which accompanies the femoral artery as far as its perforation of 

 the adductor tendon, and then accompanies the saphena vein to the foot. 

 The obturator accompanies the obturator artery, and emerges from 



