548 A MANUAL OF ANATOMY 



calcaneo-plantar, branches of the internal plantar, and branches 

 of the external plantar. 



The calcaneo-plantar nerve is a branch of the posterior tibial 

 whilst that nerve is beneath the internal annular ligament. 

 Having pierced that ligament, the nerve divides into internal 

 calcaneal and plantar branches. The former supplies the integu- 

 ment of the inner side of the heel, and the latter the inner and 

 posterior part of the sole. 



The plantar cutaneous branches of the internal plantar nerve 

 appear along the groove between the abductor hallucis and flexor 

 brevis digitorum, and, having pierced the plantar fascia, are 

 distributed to the integument of the inner half of the sole. 



The plantar cutaneous branches of the external plantar nerve 

 appear along the groove between the flexor brevis digitorum and 

 abductor minimi digiti, and, having pierced the plantar fascia, 

 are distributed to the integument of the outer half of the 

 sole. 



It is to be noted that the integument of the outer side of the heel 

 and outer border of the foot, including the outer side of the little toe, 

 is supplied by the short saphenous nerve, the external branch of 

 the musculo-cutaneous nerve also taking part in the supply of 

 the outer border, whilst the integument of the inner border of the 

 foot is supplied by the long saphenous, and by the internal branch 

 of the musculo-cutaneous nerve. 



The cutaneous arteries of the sole are branches of the internal 

 and external plantar vessels, and in their course and distribution 

 they accompany the corresponding cutaneous nerves. There is a 

 very copious supply of arteries to the integument of the heel, repre- 

 sented by the internal calcaneal branches of the external plantar 

 and posterior tibial arteries on the inner side, and the external 

 calcaneal branches of the posterior peroneal artery on the outer 

 side. 



Superficial Veins. — The superficial veins are very numerous, and 

 are for. the most part arranged in the form of a plexus, which lies 

 immediately beneath the skin. Besides this plexus, there is a 

 transverse venous arch situated near the clefts of the toes. The 

 destination of the venous blood of the plexus and transverse arch 

 is the dorsum of the foot. The blood is conveyed away from the 

 plantar subcutaneous plexus by anterior efferent and lateral efferent 

 vessels. The anterior efferent vessels terminate in the transverse 

 venous arch near the clefts of the toes. The lateral efferent vessels 

 turn round the outer and inner borders of the foot, the external 

 set terminating in the short saphenous vein, and the internal set 

 in the long saphenous vein, just where these vessels are springing 

 from the extremities of the dorsal venous arch. The transverse 

 venous arch near the clefts of the toes receives the anterior efferent 

 vessels of the plantar subcutaneous plexus, and the jjlantar digital 

 veins. The blood is conveyed away from it by means of elferent 

 veins, called inter digital, which pass upwards to the dorsum of the 



