LUMBAR PLEXUS. 



373 



spermatic vessels, and is distributed in the cremaster muscle. In 

 the female the nerve is lost in the round ligament. 



The crural branch issues beneath Poupart's ligament to supply the 

 integument of the thigh 

 (p. 140). 



4. The external cutaneous 

 nerve of the thigh (i) arises 

 from the loop between the 

 second and third nerves, 

 and appears about the 

 middle of the outer border 

 of the psoas. The nerve 

 then crosses the iliacus to 

 the interval between the 

 anterior iliac spinous 

 processes, and leaves the 

 abdomen beneath 

 Poupart's ligament, to 

 be distributed on the 

 outer aspect of the limb 

 (p. 140). 



5. The anterior crural 



(k) is the largest 

 offset of the plexus, and 

 supplies branches mainly 

 to the extensor muscles 

 of the knee-joint, and to 

 the integuments of the 

 front of the thigh and 

 inner side of the leg. 

 Taking origin from the 

 second, third, and fourth 

 nerves, this large trunk FIG. 

 appears towards the lower 



part of the psoas, where 



a. External iliac artery, cut across. 



b. Thoracic duct. 



c. Azygos veins. 



crural 

 branch. 



Course of 



external 



cutaneous 



to the thigh. 



Origin of 

 anterior 

 crural ; 



140. DISSECTION OF THE LUMBAR 

 PLEXUS AND ITS BRANCHES (!LLUSTRA- 



TIUNS F 



position 

 in the 

 abdomen ; 



it lies between that muscle 

 and the iliacus. It passes 

 from the abdomen beneath 

 Poupart's ligament ; but 

 before the final branching 

 in the thigh (p. 160), the 

 nerve sends off the follow- 

 ing twigs : 



Some small branches to 

 the iliacus are furnished 

 from the outer side of the 

 nerve. 



A branch to the femoral 

 artery, the place of origin 



Nerves : 



The figures 1 to 5 mark the trunks of the 

 five lumbar nerves. 



d. Splanchnic nerves. 



e. Last dorsal. 



/. Ilio-hypogastric. 



g. Ilio-inguinal. 



h. Grenito-crural. 



/. External cutaneous. 



k. Anterior crural. 



I. Accessory to obturator. 



n. Obturator. 



o. Gangliated cord of the sympathetic. 



its branches 



to iliacus, 



to femoral 



artery. 



