196 



THE NERVOUS SYSTEM. 



a. The N. cutaneus cruris lateralis (Fig. 128 cp) ; which, like other 

 cutaneous nerves, runs in a common sheath together with an artery 

 and vein to the skin. It arises close to the sciatic nerve. 



b. Muscular branches to the MM. peroneus, tibialis anticus, extensor 

 cruris brevis, and the flexor tarsi anterior. 



Fig. 130. 



Distribution of the A', peronnus. 



A Inner terminal twig of N. peron. comm. 



inf. 

 B Outer terminal twig of N. peron. comm. 



inf. 



cpl N. cutaneus dorsi pedis lateralis. 

 pc N. peroneus. 



pci N. peroneus communis inferior 

 pi N. peroneus lateralis. 

 pm N. peroneus medialis. 



c. The N. peroneus medialis (Fig. 

 130 pm) is the smaller of the two 

 terminal branches of the N. pero- 

 neus ; it courses with the Art. tibi- 

 alis antica under the MM. jlexores 

 tarsi anterior and posterior and sup- 

 plies the latter. 



d. The N. peroneus lateralis (Fig. 

 1 30 pi] is the larger terminal branch 

 of the N. peroneus ; it passes down- 

 wards between the heads of the M. 

 tibialis anticus to the tendon of origin 

 of the Flexor tarsi posterior, where it 

 gives off two branches (Nos. i and 2); 

 the nerve then unites with the N. 

 peroneus lateralis to form a common 

 stem, the N. peroneus communis in- 

 ferior (Ecker). The N. peroneus 

 lateralis gives off : 



(1) The N. cutaneus dorsi pedis 

 lateralis (cpl), which passes to the 

 skin of the outer side of the 

 dorsum of the foot. 



(2) A second branch to the M. ex- 

 tensor of the fourth and fifth toes. 



e. The N. peroneus communis in- 

 ferior (Fig. 130 pci) runs on the 

 dorsum of the foot in company with 

 the Art. dorsalis pedis, underneath 

 the MM. extensores digiti 1 and 11 ; 

 it supplies several branches and then 

 bifurcates. It gives off : 



(i) Branches to the MM. extensor 

 longus and brcvis digiti I. 



