628 



THE BLOOD-VASCULAR SYSTEM 



branches to the integument of the lateral side of the sole, some of which anasto- 

 mose with arteries on the lateral side of the dorsum. 



Relations. — In the first part of its course from the medial malleolus to the base of the fifth 

 metatarsal bone, the artery is covered successively by the abductor hallucis and the flexor 

 digitorum brevis, by which it is separated from the plantar aponeurosis, and may be slightly 

 overlapped in muscular subjects by the abductor quinti digiti. As it approches the base of the 

 fifth metatarsal bone it hes, as it turns medially before sinking into the foot, in the interspace 

 between the flexor digitorum brevis and the abductor quinti digiti, and is here covered only by the 

 skin and superficial fascia and the plantar aponeurosis. It hes upon the calcaneus, the quadratus 

 plantse (flexor accessoi'ius), and the flexor digiti quinti brevis. It is accompanied by the lateral 

 plantar nerve, the smaller of the two divisions into which the tibial nerve divides. In this part 

 of its course it gives off smaU branches to the contiguous muscles and to the heel. 



Fig. 502. — Plantar Arteries (Deep). (After Henle.) 



Anterior perforating branch 



First dorsal interosseous muscle 

 Metatarsal artery 

 Deep plantar branch I't^Mn |li?/ll| |I//,IL////// ^Jt^ ^^^""^^ metatarsal artery 



lrmm\mmMi/Jmm]i / ill 



Plantar metatarsal artery 



Branch of the medial plantar arterj 



Abductor hallucis muscle 



Tendon of the posterior tibial 

 muscle 

 Medial plantar artery 



Perforating branch 



Tendons of the flexor 

 digitorum longus 



Quadratus plants 



Abductor of the fifth digit 

 Lateral plantar artery 



Posterior tibial artery 



In the second part of its course the artery, which is here known as the plantar arch [areas 

 plantaris], sinks into the sole, and is covered, in addition to the skin, superficial fascia, plantar 

 aponeurosis, and flexor digitorum brevis by the tendons of the flexor digitorum longus, the 

 lumbricales, branches of the medial ])lantar nerve, and the adductor hallucis. It lies upon the 

 proximal ends of the second, third, and fourth metatarsal bones and the corresponding interos- 

 seous muscles. 



The branches of the lateral plantar artery arc: — (1) Perforating; and (2) 

 plantar metatarsal (digital). 



(1) The perforating branches [rr. perforantes], three in numbers, ascend through the 

 proximal end of tlu; second, third, and fourth spaces, between the two heads of the correspond- 

 ingly named dorsal interosseous muscles, and communicate with the proximal ends of the 

 first, second, and third dorsal metatarsal (interosseous) arteries (fig. 502). 



(2) The plantar metatarsal arteries [aa. mctatarsca' plantares] are usually four in number, 

 and pass forward in the four intermet;i,tarsal spaces, wiiich are numbered from the medial side. 

 They rest upon the inttjrosscouH muscles of their spaces, and are at first under cover of the lum- 

 bricals, but as they approach the clefts of the toes each divides into two branches, the plantar 

 digital arteries [aa. digi tales i)laiitares], which supply the contiguous sides of the toes. The 

 plantar digital branch for the medial side of the great toe is usually given off by the first plantar 

 metatarsal; that for the lateral side of the little toe is usually a separate branch from the lateral 

 end of the plantar arch. 



