THE LOWER LIMB 509 



The terminal part of the anterior peroneal artery, having reached 

 the front of the leg by passing through the inferior hiatus in the 

 interosseous membrane, descends in front of the inferior tibio- 

 fibular articulation under cover of the peroneus tertius, to both of 

 which it furnishes branches. It finally takes part in the external 

 malleolar anastomosis, along with (i) the external malleolar of the 

 anterior tibial, (2) the external tarsal of the dorsalis pedis, and 

 (3) the posterior peroneal. 



Anterior Tibial Nerve (Deep Peroneal). — ^This nerve is one of the 

 terminal branches of the external popliteal. It commences upon 

 the outer side of the neck of the fibula, where it lies between the 

 bone and the peroneus longus, and it terminates at the anterior 

 ligament of the ankle-joint, where it becomes the dorsalis pedis 

 nerve. At first it is directed downwards, forwards, and inwards 

 through the antero-external intermuscular septum and extensor 

 longus digitorum, and it comes into contact with the anterior 

 tibial artery at the junction of the upper fourth and lower three- 

 fourths of the leg. It then descends in close contact with that 

 artery as far as its termination, lying at first external to the vessel, 

 then in front of it, and finally again on its outer side. The general 

 relations of the nerve closely correspond with those of the artery 

 on the front of the leg. 



Branches. — ^These are muscular and articular. The muscular 

 branches supply the tibialis anticus, extensor longus digitorum, 

 extensor proprius hallucis, and peroneus tertius. The articular 

 branches arise from the lower part of the nerve, and are distributed 

 to the ankle-joint and inferior tibio-fibular articulation. 



Anterior Tibial Gland. — This lymphatic gland is situated in front 

 of the interosseous membrane at its upper part in close proximity 

 to the anterior tibial artery. Its afferent vessels take up l5miph 

 from the dorsum of the foot and anterior aspect of the leg in its 

 more deeply-placed parts. The efferent vessels, which are usually 

 two in number, pass backwards either above the interosseous 

 membrane or through a superior hiatus in it, lying along the anterior 

 tibial artery, and they become afferent vessels to the popliteal 

 glands. 



Dorsum of the Foot. Deep Fascia. — This is a delicate membrane 

 which is prolonged for\vards from the lambdoid ligament over the 

 long extensor tendons. Two other thin layers of deep fascia 

 are met with, one covering the extensor brevis digitorum, and 

 the other covering the dorsal interosseous muscles and the dorsal 

 surfaces of the metatarsal bones. 



Extensor Brevis Digitorum — Origin. — (i) The anterior part 



of the upper surface, and adjacent part of the external surface, 



;of the OS calcis ; and (2) the outer single portion of the lower 



division of the anterior annular ligament — that is to say, the fundi- 



form ligament of Retzius. 



I Insertion. — Into the four inner toes, namely, the great toe, 

 J second, third, and fourth, by means of four tendons in the following 



I 



