590 THE BLOOD-VASCULAR SYSTEM. 



The branches of the posterior tibial artery are the 



Peroneal. Nutrient. 



Muscular. Communicating. 



Internal Calcanean. 



The Peroneal Artery lies, deeply seated, along the back part of the fibular side 

 of the leg. It arises from the posterior tibial about an inch below the lower 

 border of the Popliteus muscle, passes obliquely outward to the fibula, and then 

 descends along the inner border of that bone, contained in a fibrous canal between 

 the Tibialis posticus and the Flexor longus hallucis, or in the substance of the 

 latter muscle to the lower third of the leg, where it gives off the anterior peroneal. 

 It then passes across the articulation between the tibia and fibula to the outer side 

 of the os calcis, where it gives off its terminal branches, the external calcanean. 



Relations. This vessel rests at first upon the Tibialis posticus, and then, for 

 the greater part of its course, in a fibrous canal between the origins of the Flexor 

 longus hallucis and Tibialis posticus, covered or surrounded by the fibres of the 

 Flexor longus hallucis. It is covered, in the upper part of its course, by the Soleus 

 and deep transverse fascia ; below, by the Flexor longus hallucis. 



PLAN OF THE RELATIONS OF THE PERONEAL ARTERY. 



In front. 

 Tibialis posticus. 

 Flexor longus hallucis. 



Outer side. / \ Inner side. 



Fibula. ( P A Try al ) Flexor longus hallucis. 



Flexor longus hallucis. 



\ 



Behind. 



Soleus. 



Deep transverse fascia. 



Flexor longus hallucis. 



Peculiarities in Origin. The peroneal artery may arise three inches below tbe Popliteus, 

 or from the posterior tibial high up, or even from the popliteal. 



Its size is more frequently increased than diminished ; and then it either reinforces the 

 posterior tibial by its junction with it, or altogether takes the place of the posterior tibial in the 

 lower part of the leg and foot, the latter vessel only existing as a short muscular branch. In 

 those rare cases where the peroneal artery is smaller than usual a, branch from the posterior 

 tibial supplies its place, and a branch from the anterior tibial compensates for the diminished 

 anterior peroneal artery. In one case the peroneal artery has been found entirely wanting. 



The anterior peroneal is sometimes enlarged, and takes the place of the dorsal artery of the 

 foot. 



The branches of the peroneal are the 



Muscular. Communicating. 



Nutrient. Posterior Peroneal. 



Anterior Peroneal. External Calcanean. 



Muscular Branches. The peroneal artery in its course gives off branches to 

 the Soleus, Tibialis posticus, Flexor longus hallucis, and Peronei muscles. 



The nutrient artery supplies the fibula. 



The Anterior peroneal pierces the interosseous membrane, about two inches 

 above the outer malleolus, to reach the fore part of the leg, and, passing down 

 beneath the Peroneus tertius to the outer ankle, ramifies on the front and outer 

 side of the tarsus, anastomosing with the external malleolar and tarsal arteries. 



The communicating is given off from the peroneal about an inch from its lower 

 end, and, passing inward, joins the communicating branch of the posterior tibial. 



The Posterior peroneal passes down behind the outer ankle to the back of the 

 external malleolus, to terminate in branches which ramify on the outer surface 

 and back of the os calcis. 



