THE HEART AND VASCULAR SYSTEM. 199 



External malleolar, supplies the outer side of the ankle. 



THE DORSALIS PEDIS artery extends from the bend of the 

 ankle, where it is continuous with the anterior tibial, to the 

 first interosseous space, where it divides into the dorsalis hal- 

 lucis and the communicating. Its branches are: 



Tar sal, supplies the tarsal articulations and the extensor 

 brevis digitorum muscle; 



Metatarsal, passes to the outer side of the foot, and gives off 

 three interosseous branches to supply the adjacent sides of the 

 toes; 



Dorsalis pollicis, or hallucis, passes along the outer border 

 of the great toe, supplying it; 



Communicating, descends between the two heads of the 

 first dorsal interosseous to complete, with the external plantar, 

 the plantar arch; 



Interosseous, branches of the tarsal branch, three in number. 



THE POSTERIOR TIBIAL ARTERY 



begins at the lower border of the popliteus muscle and descends 

 along the posterior and tibial side of the leg to the space between 

 the heel and the inner ankle, where it passes beneath the abduc- 

 tor pollicis and divides into the internal and external plantar 

 arteries. 



Relations, In the upper part of its course it lies deeply, being 

 covered by the gastrocnemius and soleus muscle, but in the lower part 

 it becomes more superficial, being covered only by the skin and the 

 fascia. 



Its branches are: 



Peroneal, descends the inner border of the fibula, supplying 

 the muscles and skin of that region and the back of the ankle ; 



Anterior peroneal, a branch of the peroneal, pierces the 

 lower part of the interosseous membrane to supply the dorsum 

 and outer side of the tarsus ; 



Muscular, supplies the posterior muscles; 



Nutrient, supplies the tibia, being the largest nutrient artery 

 in the body; 



Communicating, passes to the peroneal ; 



Internal calcanean, supplies the inner side of the sole and 

 heel. 



THE INTERNAL PLANTAR ARTERY, the smaller of the two, 

 passes along the inner side of the foot between the abductor 

 pollicis and the flexor brevis digitorum to the inner border of 

 the great toe, anastomosing with its digital branch. 



