POSTERIOR TIBIAL ARTERY 165 



of the femur, posterior ligament of knee-joint, posterior surface 

 of popliteus, and is covered by outer border of semimembranosus, 

 and adjacent borders of heads of gastrocnemius. On its outer 

 side above lies the internal popliteal nerve, which crosses its 

 middle and lies on its inner side below. 



The Popliteal Vein lies behind the artery below, then crosses 

 its middle, lying between it and the internal popliteal nerve, and 

 passes upwards on its outer side. 



Brandies. Muscular to the adjacent parts. 



Articular to the knee-joint (five in number) . 



Posterior Tibial Artery. The larger of the two terminal 

 branches of the popliteal artery commences at the lower border 

 of popliteus and terminates at the lower border of the internal an- 

 nular ligament midway between the tip of the internal malleolus 

 and the os calcis. It ends by dividing into the internal and 

 external plantar arteries. The artery lies between the deep and 

 superficial groups of muscles on the back of the leg, and is in 

 contact in front from above downwards with tibialis posticus, 

 flexor longus digitorum, posterior surface of tibia, posterior 

 ligament of ankle-joint. It is covered by, successively, gas- 

 trocnemius, soleus, skin and fascia, internal annular ligament, 

 origin of abductor hallucis. 



The internal popliteal nerve lies above on the inner side of the 

 artery, and crosses it about an inch and a half below its origin, 

 and is continued down its outer side. 



The artery is accompanied by venae comites, one on each side. 



Beneath the internal annular ligament the tendons of tibialis 

 posticus and flexor longus digitorum lie in the front of the artery 

 and that of flexor longus hallucis behind it. 



Branches. 1. Muscular to soleus and the deep muscles. 



2. Cutaneous to skin of back of leg. 



3. Internal Malleolar to the inner surface of the 



internal malleolus, which anastomoses with a 

 similar branch of the anterior tibial artery. 



4. Peroneal, the largest branch of the posterior 



tibial artery, arises about an inch below the 

 lower border of popliteus, and, curving 

 outwards, supplies the peroneal muscles. 



