POSTERIOR TIBIAL AND PERONEAL ARTERIES. 331 



border of the popliteus muscle to the concavity of the os calcis, where it 

 divides into the internal and external plantar artery. 



Relations. In its course downwards it lies first upon the tibialis posti- 

 cus, next on the flexor longus digitorum, and then on the tibia ; it is 

 covered in by the intermuscular fascia which separates it above from the 

 soleus, and below from the deep fascia of the leg and the integument. It 

 is accompanied by its vena? comites, and by the posterior tibial nerve, 

 which latter lies at first to its outer side, then superficially to it, and again 

 to its outer side. 



Plan of the Relations of the Posterior Tibial Artery. 



Superficially. 



Soleus, 

 Deep fascia, 

 The intermuscular fascia. 



Inner Side. 

 Vein. 



Posterior Tibial 

 Artery. 



Outer Side. 



Posterior tibial nerve, 

 Vein. 



Deeply. 



Tibialis posticus, 

 Flexor longus digitorum, 

 Tibia. 



Branches. The branches of the posterior tibial artery are the 



Peroneal, Internal calcanean, 



Nutritious, Internal plantar, 



Muscular, External plantar. 



The Peroneal artery is given off from the posterior tibial at about two 

 inches below the lower border of the popliteus muscle ; it is nearly as 

 large as the anterior tibial artery, and passes obliquely outwards to the 

 fibula. It then runs downwards along the inner border of the fibula to 

 its lower third, where it divides into the anterior and posterior peroneal 

 artery. 



Relations. The peroneal artery rests upon the tibialis posticus muscle, 

 and is covered in by the soleus, the intermuscular fascia, and the flexor 

 ongus pollicis, having the fibula to its outer side. 



Plan of the Relations of the Peroneal Jlrtery. 



In Front. 



Soleus, 



Intermuscular fascia, 

 Flexor longus pollicis. 



Outer Side. 

 Peroneal Artery. 



Fibula. 



Behind. 

 Tibialis posticus. 



