432 



MUSCULOCUTANEOUS NERVE. 



Fig. 195.' 



fibula, where it pierces the origin of the peroneus longus muscle, and 

 divides into two branches, the anterior tibial and musculo-cutaneous. 



The Branches of the peroneal nerve previously to its division are, the 

 communicans peronei, cutaneous, articular, and muscular. The commu- 

 nicans peronei^ much smaller than the communicans poplitei, crosses the 

 external head of the gastrocnemius to the middle of the leg. It there 

 sends a large branch to join the communicans poplitei and constitute the 

 external saphenous nerve, and descends very much reduced in size with 

 the external saphenous vein to the side of the external ankle, to which and 

 to the integument of the heel it distributes filaments. The cutaneous branch 

 passes down the outer side of the leg, supplying the integument. The 

 articular is a small branch distributed to the knee joint. The muscular 

 branches are twigs to the short head of the biceps, peroneus longus, and 

 tibialis anticus. 



The ANTERIOR TIBIAL NERVE commences at the 

 bifurcation of the peroneal, upon the head of the fibula, 

 and passes beneath the upper part of the extensor longus 

 digitorum, to reach the outer side of the anterior tibial 

 artery, just as that vessel has emerged through the open- 

 ing in the interosseous membrane. It descends the an- 

 terior aspect of the leg with the artery ; lying at first to 

 its outer side, and then in front of it, and near the ankle 

 becomes again placed to its outer side. Reaching the 

 ankle, it passes beneath the annular ligament ; accom- 

 panies the dorsalis pedis artery, supplies the adjoining 

 sides of the great and second toes, and communicates 

 with the internal peroneal cutaneous nerve. 



The Branches given off by the anterior tibial nerve 

 are, muscular to the muscles in its course, and on the 

 foot a tarsal branch \vhich passes beneath the extensor 

 brevis digitorum, and distributes filaments to the inter- 

 ossei muscles and to the articulations of the tarsus and 

 metatarsus. 



The MUSCULO-CUTANEOUS NERVE passes downwards 

 in the direction of the fibula, in the substance of the 

 peroneus longus ; it then passes forwards to get between 

 the peroneus longus and brevis, and at the lower third 

 of the leg pierces the deep fascia, and divides into two 

 peroneal cutaneous branches. In its course it gives off 

 several branches to the peronei muscles. 



The Peroneal cutaneous nerves pass in front of the 

 ankle joint, and are distributed to the integument of 

 the foot and toes ; the external supplying three toes 

 and a half, and the internal one and a half. They 

 communicate with the saphenous and anterior tibial 



nerves. The external saphenous nerve frequently supplies the fifth toe and 



the adjoining side of the fourth. 



* A view of the anterior tibial nerve. 1. The peroneal nerve. 2, 3. The anterior 

 tibial nerve accompanying the artery of the same name. 



