552 



ABDOMEN 



nerve. But other branches come off from certain of these 

 divisions. Thus, the lower root of the genito-femoral springs 

 from the anterior division of the second lumbar nerve, whilst 

 the two roots of the lateral cutaneous nerve of the thigh 

 take origin from the posterior divisions of the second and 

 third lumbar trunks. 



The ilio-hypogastric nerve emerges from the lateral border of 

 the psoas, and crosses the quadratus lumborum obliquely. 



T.xu 



Quadratus 

 lumborum ' 

 Intertransverse ~~ 



muscles 

 Quadratus ^ ' 

 lumborum "" ~ 



Intertransverse 



muscles 



Quadratus t- 1 1 



lumborum .._. 

 Psoas 



Llll 



Quadratus 



lumborum 



Psoas 



Quadratus^ 

 lumborum ,_ 



Genito-femoral nerve 

 (O.T. genito-crural) 



Lumbo-sacral trunk 

 Lumbo-inguinal nerve 

 (O. T. crural branch of genito- 

 crural) 



External spermatic nerve (O.T. 

 genital branch of genito-crural) 



Last thoracic nerve 



Lateral branch 

 -Anterior branch 



io-hypogastric nerve 



Lateral branch 

 Anterior branch 



k " Ilio-inguinal nerve 



Lateral cutaneous nerve 

 of thigh (O.T. external 

 cutaneous) 



Branch to iliacus 



Femoral nerve (O. T. 

 anterior crural) 

 Accessory obturator nerve 

 --Obturator nerve 



FIG. 212. Diagram of Lumbar Plexus. 



Reaching the crest of the ilium, it leaves the abdomen by 

 piercing the transversus abdominis muscle. Its further 

 course has already been studied (p. 394)- It gi ves off an 

 iliac branch to the skin of the glutaeal region, and a hypogastric 

 branch to the skin over the lower part of the abdominal wall. 

 The ilio-inguinal nerve is smaller than the ilio-hypogastric, 

 and leaves the psoas almost at the same point. It runs 

 obliquely downwards and laterally over the quadratus lum- 

 borum and the upper part of the iliacus, and disappears from 



