NER VES 167 



humeral, has no anterior branch ; the posterior branch crosses 

 the axilla, joins the lesser internal cutaneous nerve, and 

 supplies the integument of the inner side of the arm. 



The LOWER six pass like the upper ones to the. front of the 

 intercostal spaces, thence between the internal oblique and 

 transversalis to the sheath of the rectus, which they perforate, 

 and terminate near the middle line as anterior cutaneous branches 

 of the abdominal wall. 



Branches : 



Lateral cutaneous: supply the integument of the abdomen, 

 having anterior and posterior branches. 



PECULIAR DORSAL NERVES : The ist nerve : its anterior 

 primary division is mostly consumed in the brachial plexus, 

 but a small branch is given off to the ist intercostal space, 

 which has no lateral cutaneous branch. The i2th nerve does 

 not lie in an intercostal space, but below the I2th rib in front 

 of the quadratus lumborum ; it then pierces the posterior 

 aponeurosis of the transversalis, passing forwards between 

 transversalis and internal oblique to end by perforating rectus ; 

 is remarkable for the large size of its lateral cutaneous branch, 

 which does not divide, but, piercing internal and external 

 obliques, passes over iliac crest and supplies skin over gluteal 

 region as far down as great trochanter. 



LUMBAR : five on each side. The ANTERIOR PRIMARY DIVI- 

 SIONS increase in size from above downwards, and near their 

 origin communicate with the sympathetic ganglia, the upper 

 four forming the lumbar plexus ; that of the 5th joins with 

 the ist sacral to form the lumbo-sacral cord. The POSTERIOR 

 PRIMARY DIVISIONS pass backwards between the transverse 

 processes and divide into internal and external branches. 

 These are seen to be separated by the longissimus dorsi. 

 The internal branches end in the muscles, and all the external 

 gjve muscular branches; the upper three also give cutaneous 

 branches to gluteal region. 



NERVES OF THE LOWER EXTREMITY. 



LUMBAR PLEXUS : formed in the psoas by the communica- 

 tions of the anterior primary divisions o the four upper 

 lumbar nerves in the following manner : 



The ist gives off the ilio-hypogastric, the ilio-inguinal, a 

 branch to the genito-crural, and a communicating branch to 

 the 1 2th dorsal and 2nd lumbar. 



The 2nd gives off branches to the genito-crural, and external 



