632 A MANUAL OF ANATOMY. 



popliteus muscle to the point mid-way between the internal 

 malleolus and the point of the heel, at which place it divides 

 into the internal and external plantar vessels. 



The artery is covered by the skin, superficial and deep 

 fascia, the gastrocnemius and soleus muscles, and the deep 

 intermuscular fascia of the leg. The muscular covering is 

 wanting in the lower third of its course. 



The artery crosses the posterior surface of the tibialis 

 posticus, flexor longus digitorum, tibia, and the internal 

 lateral ligament of the ankle joint. At the ankle the artery 

 is covered by the annular ligament and origin of the abduc- 

 tor hallucis muscle. 



The artery has an accompanying vein upon either side 

 which frequently communicate by cross branches. The 

 posterior tibial nerve is at its beginning at the inner side of 

 the artery, but crosses it where the peroneal artery arises, 

 and continues at the outer side of the artery for the rest of 

 its course. 



Behind the internal malleolus the posterior tibial artery 

 is the central structure of five others. 



From before backward the order is, tendon of the tibialis 

 posticus, tendon of the flexor longus digitorum, artery, 

 posterior tibial nerve, and (at a little distance, and on a 

 deeper plane) the tendon of the flexor longus hallucis. 

 Besides these the venae comites lie, one in front the other 

 behind the artery and next to it. 



Branches. (i) Muscular, numerous to the surrounding 

 muscles. (2) The nutrient artery of the tibia, largest in 

 the body, arises near the beginning of the posterior tibial, 

 and enters the nutrient foramen at the upper and middle 

 thirds of the outer border of the tibia. (3) Cutaneous (two 

 or three), which reach the inner side of the leg between the 

 superficial and deep sets of muscles. (4) A communicating 



