ARTERIES 95 



Metatarsal : arises near bases of metatarsals, directed out- 

 wards in an arched direction, beneath short extensor of toes 

 to outer side of foot, near bases of xnetatarsal. bones ; anas. 

 tarsal, external plantar. From the convexity of arch proceed 

 three dorsal interosseous branches to three outer metatarsal 

 spaces. They supply the interossei and divide at cleft of 

 toes into digital branches ; the most external one supplies 

 also outer side of little toe. Each interosseous artery com- 

 municates at the cleft of the toes with the plantar digitals by* 

 an anterior perforating branch, and at the back of the inter- 

 osseous space with the plantar arch by a posterior perforating 

 branch. 



The 1st dorsal interosseous artery : arises as dorsalis pedis 

 is about to dip down into sole. It lies over dorsum of ist 

 interosseous space, and divides at cleft to supply contiguous 

 sides of ist and 2nd toes, having previously given off a branch 

 to inner side of ist toe. 



Plantar digital, or arteria magna hallucis : arises in sole, 

 passes forwards in ist interosseous space to cleft, where it 

 divides into two branches for contiguous sides of ist and 2nd 

 toes, having previously given off a branch of inner side of 

 great toe. 



THE POSTERIOR TIBIAL ARTERY. 



Extent. From lower border of popliteus to lower edge of 

 internal annular ligament of ankle, there dividing into internal 

 and external plantar, at a spot midway between internal 

 malleolus and heel. 



Course. At first midway between tibia and fibula, after- 

 wards approaches tibia and lies on it. 



Relations. Upper frds covered by gastrocnemius and 

 soleus. Lower rd superficial between inner border of Tendo 

 Achillis and inner border of tibia. Posterior tibial nerve is 

 at first on inner side, but about i inch down crosses 

 posteriorly to reach outer side. Has vends comites, and lies 

 on tibialis posticus, flexor longus digitorum, tibia, and back 

 of ankle-joint. 



Relations of artery at inner malleolus, from within outwards. 

 Tibialis posticus and flexor longus digitorum tendons, vein, 

 artery, vein, nerve, flexor longus hallucis tendon. 



Branches : 



Peroneal : arises i inch from popliteus, courses obliquely 

 to fibula, then along inner border of that bone, between origins 

 of tibialis posticus and flexor longus hallucis, to lower part of 

 interosseous membrane, where it gives off anterior peroneal, 



