662 SPINAL NERVES. 



part of the interosseous membrane, and reaches the outer side of the anterior 

 tibial artery above the middle of the leg ; it then descends with the artery to 

 the front of the ankle-joint, where it divides into an external and an internal 

 branch. This nerve lies at first on the outer side of the anterior tibial artery, 

 then in front of it, and again at its outer side at the ankle-joint. 



The branches of the anterior tibial nerve, in its course through the leg, are 

 the muscular nerves to the Tibialis Anticus, Extensor Longus Digitorum, and 

 Extensor Proprius Pollicis muscles. 



The external or tar sal branch of the anterior tibial, passes outwards across the 

 tarsus, beneath the Extensor Brevis Digitorum, and, having become ganglionic, 

 like the posterior interosseous nerve at the wrist, supplies the Extensor Brevis 

 Digitorum and the articulations of the tarsus and metatarsus. 



The internal branch, the continuation of the nerve, accompanies the dorsalis 

 pedis artery along the inner side of the dorsum of the foot, and, at the first 

 interosseous space, divides into two branches, which supply the adjacent sides 

 of the great and second toes, communicating with the internal division of the 

 musculo-cutaneous nerve. 



The Musculo- Cutaneous Nerve (Fig. 356) supplies the muscles on the fibular 

 side of the leg, and the integument of the dorsum of the foot. It passes for- 

 wards between the Peronei muscles and the Extensor Longus Digitorum, pierces 

 the deep fascia at the lower third of the leg, on its front and outer side, and 

 divides into two branches. This nerve, in its course between the muscles, 

 gives off muscular branches to the Peroneus Longus and Peroneus Brevis, and 

 cutaneous filaments to the integument of the lower part of the leg. 



The internal branch of the musculo-cutaneous nerve, passes in front of the 

 ankle-joint, and along the dorsum of the foot, supplying the inner side of the 

 great toe, and the adjoining sides of the second and third toes. It also supplies 

 the integument of the inner ankle and inner side of the foot, communicating 

 with the internal saphenous nerve, and joins with the anterior tibial nerve, 

 between the great and second toes. 



The external branch, the larger, passes along the outer side of the dorsum of 

 the foot, to be distributed to the adjoining sides of the third, fourth, and fifth 

 toes. It also supplies the integument of the outer ankle and outer side of the 

 foot, communicating with the short saphenous nerve. 



The distribution of these branches of the musculo-cutaneous nerve will be 

 found to vary; together, they supply all the toes excepting the outer side of the 

 little toe, and the adjoining sides of the great and second toes. 



