5M 



A MANUAL OF ANATOMY 



Branches. — The branches are as follows : external or tarsal, 

 interosseous, and terminal. 



The external or tarsal branch arises from the dorsalis pedis 

 nerve as soon as it emerges from beneath the lower division of 

 the anterior annular ligament. It passes outwards beneath the 

 extensor brevis digitorum, and in that situation it presents a 

 gangliform enlargement from which branches are furnished to the 

 extensor brevis digitorum and the tarsal articulations. Three 



interosseous branches also arise from it, 

 which pass over the dorsal aspects of the 

 three outer interosseous spaces, supply- 

 ing the adjacent tarso-metatarsal and 

 metatarso-phalangeal articulations. The 

 interosseous branch, which lies over the 

 second interosseous space, usually sup- 

 plies a small twig to the dorsal inter- 

 osseous muscle of that space. 



The interosseous branch passes over 

 the dorsal aspect of the first interosseous 

 space, supplying the adjacent tarso-meta- 

 tarsal and metatarso-phalangeal articula- 

 tions. It also gives a twig to the first 

 dorsal interosseous muscle. 



The terminal branches are the dorsal 

 collateral digital nerves for the con- 

 tiguous sides of the great toe and the 

 second. 



Dorsal Venous Arch. — ^This arch is 

 superficial to the deep fascia, and is 

 situated well forward upon the dorsum 

 of the foot, being about 2 inches from 

 the webs of the toes. The convexity of 

 the arch, which is but slight, is directed 

 forwards. It receives (i) the dorsal 

 digital veins, (2) small veins from the 

 dorsum of the foot, and (3) the efferent 

 interdigital veins which come from the 

 plantar transverse venous arch situated 

 near the clefts of the toes. The blood 

 is carried away from the dorsal venous 

 arch by the two saphenous veins. The 

 internal or long saphenous vein arises 

 from the inner end of the arch, and, having received branches 

 from the superficial plantar venous plexus which turn round the 

 inner border of the foot, it passes in front of the internal malleolus, 

 and thus reaches the inner side of the leg. Its further course has 

 been previously described. 



The external or short saphenous vein arises from the outer ends 

 of the arch, and, having received branches from the superficial 



Fig. 247. — The External 



Saphenous Vein and its 



Tributaries. 



