POSTERIOR TIBIAL ARTERY. 359 



The Dorsalis liallucis runs forward upon the first dorsal interosse- 

 ous muscle, and at the base of the first phalanx divides into two 

 branches, one of which passes inwards beneath the tendon of the ex- 

 tensor proprius pollicis, and is distributed to the inner border of the 

 great toe, while the other bifurcates for the supply of the adjacent 

 sides of the great and second toes. 



The Communicating artery passes into the sole of the foot between 

 the two heads of the first dorsal interosseous muscle, and inosculates 

 with the termination of the external plantar artery. 



Besides the preceding, numerous branches are distributed to the 

 bones and articulations of the foot, particularly along the inner border 

 of the latter. 



POSTERIOR TIBIAL ARTERY. 



The posterior tibial artery passes obliquely downwards along the 

 tibial side of the leg from the lower 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 

 posticus, next upon the flexor longus digitorum, and then upon the 

 tibia ; it is covered in by the iutermuscular 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 venae 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. Outer Side. 



Vein. Arterv Posterior tibial nerve, 



Vein. 



Deeply. 



Tibialis posticus, 

 Flexor longus digitorum, 

 Tibia. 



Branches. The branches of the posterior tibial artery are the 



Peroneal, 

 Nutritious, 

 Muscular, 

 Internal calcanean, 

 Internal plantar, 

 External plantar. 



