THE SACRAL PLEXUS 



1061 



(Fig. 778); muscular branches, which supply the Abductor hallucis and Flexor 

 brevis digitorum; articular branches, to the articulations of the tarsus and meta- 

 tarsus; and four plantar digital branches (nn. digitales plantares proprii). The 

 first (innermost) branch becomes cutaneous about the middle of the sole, between 

 the Adductor hallucis and Flexor brevis digitorum; the three outer branches pass 

 between the divisions of the plantar fascia in the clefts between the toes. They 

 are distributed in the following manner: The first supplies the inner border of 

 the great toe, and sends a filament to the Flexor brevis hallucis muscle; the second 

 bifurcates, to supply the adjacent sides of the great and second toes, sending a fila- 

 ment to the First lumbrical muscle; the third supplies the adjacent sides of the second 

 and third toes; the fourth supplies the corresponding sides of the third and fourth 

 toes, and receives a communicating branch from the external plantar nerve (Fig. 

 736). Each digital nerve gives off cutaneous and articular filaments; and opposite 

 the last phalanx sends a dorsal branch, which supplies the structures around the 



nail, the continuation of the nerve being dis- 

 tributed to the ball of the toe. It will be 

 observed that the distribution of these branches 

 is precisely similar to that of the median nerve 

 in the hand. 



The External Plantar Nerve (n. plantaris later- 

 alis) (Fig. 777), the smaller of the two, completes 

 the nerve supply to the structures of the sole of 

 the foot (Fig. 778), being distributed to the little 



Internal 



or 



Medial 

 plantar. 



External 



or 



Lateral 

 plantar. 



Deep 

 branch. 



FIG 777. The plantar nerves. 



FIG. 778. Areas of distribution of the cutaneous nerves of the 

 sole (W Keiller, in Gerrish's Text-book of Anatomy.) 



toe and outer half of" the fourth, as well as to most of the deep muscles, its dis- 

 tribution being similar to that of the ulnar nerve in the hand. It passes obliquely 

 forward with the external plantar artery to the outer side of the foot, lying between 

 the Flexor brevis digitorum and Flexor accessorius; and in the interval between 

 the former muscle and Abductor minimi digiti, divides into a superficial and a 

 deep branch. Before its division it supplies the Flexor accessorius and Abductor 

 minimi digiti. 



The superficial branch (ramus superficialis) separates into two digital nerves. 

 One, the smaller of the two, supplies the outer side of the little toe, the Flexor 

 brevis minimi digiti, and the two Interosseous muscles of the fourth metatarsal 



