THE POPLITEAL ARTERY 



497 



hallucis muscle, between the posterior tibial and peroneal arteries, about an inch 

 above the ankle-joint. A second loop of communication between these vessels is 

 sometimes present, lying in the fat beneath the tendo Achillis. 



5. One or two small internal malleolar branches pass inwards beneath the 

 flexor longus digitorum and tibialis posticus muscles, and ramify over the internal 



Fig. 393. DEEP VIEW OP THK ARTERIES OF THE BACK OF 

 THE RIGHT LEG. (Tiedemann. ) 



a, lower part of adductor magnus muscle ; b, origin of inner head 

 of gastrocnemius ; c, outer head and pluntaris ; d, tendon of semi- 

 rnembranosus ; e, popliteus ; /, fibular origin of soleus ; </, peroneus 

 longus ; h, flexor longus hallucis ; i, flexor longus digitorum ; 1, 

 upper part of popliteal artery ; 2, origin of its superior articular 

 branches ; 3, origin of its inferior articular branches ; the middle or 

 azygos branch is seen between these numbers ; 4, division of popliteal 

 into anterior and posterior tibial arteries ; 5, 5', posterior tibial ; 

 at 5', the internal malleolar branches are seen passing inwards, 

 and the communicating branch outwards ; 6, peroneal artery ; 6', its 

 continuation as posterior peroneal ; 7. calcaneal branches ; 8, external 

 branches of the metatarsal of the dorsal artery of the foot. 



malleolus, where they anastomose with similar offsets 

 from the anterior tibial artery. 



6. The peroneal artery (iv) lies deeply along the 

 back part of the leg, close to the fibula. Arising from 

 the posterior tibial artery about an inch below the lower 

 border of the popliteus muscle, it inclines at first slightly 

 outwards towards the fibula, being covered by the soleus 

 and the deep layer of fascia, and resting upon the tibialis 

 posticus muscle ; it then descends vertically along the 

 inner border of the bone and under cover of the flexor 

 longus hallucis, being contained in a fibrous canal between 

 the origins of that muscle and the tibialis posticus. 

 Opposite the lower end of the interosseous space it gives 

 off the anterior peroneal branch, and is thence continued 

 downwards, being much reduced in size and taking the 

 name of posterior peroneal artery, over the lower tibio- 

 fibular articulation and behind the external malleolus, 

 to terminate in branches which ramify on the outer sur- 

 face and back of the os calcis. The peroneal artery is 

 accompanied by two vencR comites, and, until it enters the 

 flexor longus hallucis, by the branch of the posterior 

 tibial nerve to that muscle. 



Branches. (a) Muscular branches pass from the pero- 

 neal artery to the soleus, tibialis posticus, flexor longus 

 hallucis, and peronei muscles. Small branches also per- 

 forate the interosseous membrane, and are distributed 

 to the extensor longus digitorum and peroneus tertius 

 muscles. 



(b) A. medullary artery enters the fibula. 



(c) The communwating branch, lying close behind the tibia about an inch from its 

 lower end, is a branch of variable size, which connects the peroneal and posterior 

 tibial arteries, and also sends small twigs beneath the muscles to ramify 

 over the inner side of the lower part of the tibia. This branch is sometimes 

 wanting. 



