n6 



ANATOMY AND PHYSIOLOGY 



fibula; the medial surface of the tibia, having no muscles upon it, 

 is called subcutaneous. 



The tibialis anterior. Origin. The shaft and head of the 

 tibia (lateral surface)^and the interosseous membrane. 



Insertion. The first cuneiform and first 

 metatarsal bones. 



Nerve. Deep peroneaL 



The peroneus tertius. Origin. The shaft 

 of the fibula (lower part). Insertion. The 

 fifth metatarsal bone. 



Action of the two. To flex the ankle. The 

 tibialis acting alone lifts the medial border of 

 the foot; the peroneus lifts the lateral border. 



Nerve. Deep peroneal. 



The 'extensor hallucis longus, or long ex- 

 tensor of the great toe. Origin. The shaft of 

 the fibula and the interosseous membrane. 

 Insertion. The last phalanx of the great toe. 



Action. To extend the great toe. 



Nerve. Deep peroneal. 



The extensor digitorum longus, or long 

 extensor of the toes. Origin. The shaft of 

 the fibula and interosseous membrane (a few 

 fibers from head of tibia). Insertion. By 

 four tendons on the second and third pha- 

 langes of the four lateral toes, like the similar 

 extensor of the fingers. 



Action. To extend the toes. 



Nerve. Deep peroneal. 



Note. These two muscles, since they pass 

 in front of the ankle-joint, flex it. 



FIG. 95. MUSCLES 

 OF THE LEG, ANTERIOR. 



i, Rectus femoris; 2, 

 tibia; 3, tibialis ante- 

 rior; 4, long extensor 

 of toes; 5, long extensor 

 of great toe; 6, peroneus 

 tertius; 7, 8, peroneus 

 longus, p. brevis; 9, 10, 

 lateral and medial 

 heads, gastrocnemius; 

 ii, short extensor of 

 toes; 12, annular liga- 

 ment. (Sappey.) 



On the dorsum of the foot the extensor digitorum brevis has four slender 

 tendons for the four medial toes. 



Nerve. Deep peroneal. 



