520 



LUMBAR NERVES. 



Fig. 213.* the iliacus internus muscle, and runs be- 



neath the fascia covering it, to reach the 

 interval between the anterior and superior 

 spinous processes of the ilium, where it 

 passes from the pelvis underneath Pou- 

 part's ligament. About two inches be- 

 low this point it pierces the fascia lata, 

 and is distributed to the integuments of 

 the outer and posterior part of the thigh, 

 the anterior filaments which it gives off 

 reaching as far down as the knee. This 

 external cutaneous is sometimes sent off 

 from the anterior crural. 

 Another branch is sent off from the 

 second lumbar called the External Sper- 

 matic, or genito-crural, which perforates 

 the front of the psoas muscle and the fas- 

 cia covering it. It descends along the 

 \\ inner border of this muscle till it meets 



with the external iliac artery near Pou- 

 part's ligament, where it divides into a 

 spermatic or genital, and a crural branch. 

 The spermatic branch passes out from the 

 abdomen with the cord and is distributed 

 on its cremasteric investment. In the 

 female it sends branches to the round lig- 

 ament. The crural or femoral branch runs 

 out through the sheath of the vessels, just 

 at the outer margin of the femoral artery, 

 pierces the sheath and is spent upon the 

 integuments of the inguinal region, or 

 upper third of the front of the thigh.f 



* A diagram showing the lumbar and sacral plexuses, with the nerves of the 

 lower extremity. 1. The five lumbar nerves ; which, with a branch from the 

 last dorsal constitutes the lumbar plexus. 2. The four upper sacral nerves ; 

 which, with the last lumbar, form the sacral plexus. 3. The two musculo- 

 cutaneous nerves, branches of the first lumbar nerve. 4. The external cuta- 

 neous nerves. 5. The genito-crural nerve. 6. The crural or femoral nerve. 

 7. Its muscular branches. 8. Its cutaneous branches, middle cutaneous. 9. 



f The external spermatic often comes off from the second lumbar nerve. 



