204 



DISSECTION OF THE FOOT. 



Plantar 



nerves also 

 two. 



Internal 

 nerve to 

 three toes 

 and a half ; 



muscular 

 branches ; 



digital 

 nerves are 

 divided, ex- 

 cept first, 



and give 

 muscular 

 branches, 



cutaneous 

 and articu- 

 lar offsets. 



External 

 plantar to 

 one toe and 

 a half ; 



has super- 

 ficial and 

 deep parts ; 



branches to 

 muscles ; 



tAvo digital 

 branches, 



one single, 

 one divided. 



Distribution 

 like others. 



The PLANTAR NERVES (fig. 77) are derived from the bifurcntioi 

 of the posterior tibial trunk behind the inner ankle. They are tw< 

 in number, and accompany the plantar arteries ; but the large 

 nerve lies with the smaller blood-vessel. 



The INTERNAL PLANTAR NERVE (*) courses between the short 

 flexor of the toes and the abductor haliucis, and giving but feu 

 muscular offsets, divides into four digital branches (fig. 75, 2 , 

 for the supply of both sides of the inner three toes, and half the 

 fourth ; it resembles thus the median nerve of the hand in the 

 distribution of its branches. 



Muscular offsets are given b the trunk to the flexor brevie 



few 



tv:iyi 



digitorum and the abductor hallucis ; and 

 perforate the fascia. 



The four digital nerves have a numerical designation, and th( 

 first is nearest the inner border of the foot. The branch ( 2 ) to tlit 

 inner side of the great toe is undivided, but the others are bifurcatec 

 at the cleft between the toes. 



Muscular branches are furnished by two of these nerves before 

 they reach the toes ; thus, the first supplies the flexor bivvis 

 hallucis ; and the second gives a branch to the innermost lumbrical 

 muscle. 



Digital nerves on the toes. Each of the outer three nerves, being 

 divided at the cleft between the toes, supplies the contiguous sides 

 of two toes, while the first belongs altogether to the inner side of 

 the great toe ; all give offsets to the integuments, and the cut-is 

 beneath the nail, and articular filaments are distributed to the 

 joints as in the fingers. 



The EXTERNAL PLANTAR NERVE (fig. 77, 2 ) is spent chiefly in 

 the deep muscles of the sole of the foot, but it furnishes digital 

 nerves to both sides of the little toe, and the outer side of the 

 fourth. It corresponds in its distribution with the ulnar nerve in 

 the hand. 



It has the same course as the external plantar artery, and divides 

 at the outer margin of the flexor brevis digitorum into a superficial 

 and a deep portion ; the former gives origin to the two digital 

 nerves ; but the latter accompanies the arch of the plantar artery 

 into the foot, and will be dissected afterwards (p. 210). 



While the external plantar nerve is concealed by the short flexor 

 of the toes, it gives muscular brandies to the abductor minimi digit! 

 and the flexor accessorius. 



The digital brandies of the external plantar nerve (fig. 75) are 

 two. One (7) is undivided and is distributed to the outer side of 

 the little toe, giving offsets to the flexor brevis minimi digiti, 

 and oftentimes to the interosseous muscles of the fourth space. 

 The other ( 8 ) bifurcates at the cleft between the outer two toes, 

 supplying their collateral surfaces, and communicates in the foot 

 with the last digital branch of the internal plantar nerve. 



On the sides of the toes the digital nerves have the same dis- 

 tribution as those from the other plantar trunk, and end like them 

 in a tuft of fine branches at the extremity of the digit. 



