624 DISSECTION OF THE FOOT. 



The last two digital are joined by superficial digitalis branches of the 

 internal plantar at the root of the toes. 



On the sides of the toes the disposition of the arteries is like that of the 

 digital in the hand. They extend to the end, where they unite in an 

 arch, and give offsets to the sides and ball of the toe : and the artery on 

 the second digit anastomoses with a branch from the anterior tibial artery. 

 Near the front of both the metatarsal and the next phalanx, they form 

 anastomotic loops beneath the flexor tendons, from which the phuUmgeal 

 articulations are supplied. 



The DORSAL ARTERY OF THE FOOT (fig. 213, e) enters the sole at the 

 posterior part of the first (inner) metatarsal space, and ends by inoscu- 

 lating with the plantar arch. By a large digital artery it furnishes 

 branches to both sides of the great toe and half the next, in the same man- 

 ner as the radial artery in the hand is distributed to one digit and a half. 



The digital branch (/) (art. magna pollicis) extends to the front of the 

 first interosseous space, and divides into collateral branches (A) for the 

 contiguous sides of the great toe and the next; near the head of the meta- 

 tarsal bone it sends inwards, beneath the flexor muscles, a digital branch 

 (g) for the inner side of the great toe. 



These arteries have the same arrangement along the toes as the other 

 digital branches; and that to the second digit anastomoses at the end of 

 the toe with a branch of the plantar arch. 



EXTERNAL PLANTAR NERVE (fig. 213, 2 ). The deep branch ( 4 ) of this 

 nerve accompanies the arch of the artery, and ends internally in the ad- 

 ductor pollicis. It furnishes branches to all the interossei; to the trans- 

 versalis pedis; and to the two external lumbrical muscles. The nerve 

 corresponds with the deep portion of the ulnar nerve in the hand. 



Dissection. It will be needful to remove the transversalis pedis muscle, 

 to see a ligament across the heads of the metatarsal bones. 



The transverse metatarsal ligament is a strong fibrous band, like that 

 in the hand (p. 280), which connects together all the metatarsal bones at 

 their anterior extremity. A thin fascia covering the interossei muscles is 

 connected to its hinder edge. It is concealed by the transversalis pedis, 

 and by the tendons, vessels, and nerves of the toes. 



Dissection. To complete the dissection of the last layer of muscles, the 

 flexor brevis minimi digiti may be detached and thrown forwards. Di- 

 viding then the metatarsal ligament between the bones, the knife is to be 

 carried directly backwards for a short distance in the centre of each inter- 

 osseous space, except the first, in order that the two interossei muscles 

 may be separated from each other. All the interossei are visible in the 

 sole of the foot. 



The fascia covering the. muscles should be taken away if any remains, 

 and the branches of the external plantar nerve to them should be dissected 

 out. 



FOURTH LAYER OF MUSCLES (fig. 213). In the fourth and last layer 

 of the foot are contained the interossei, and the tendons of the tibialis pos- 

 ticus and peroneus longus. 



The INTEROSSEI MUSCLES (fig. 213) are situate in the intervals between 

 the metatarsal bones : they consist of two sets, plantar and dorsal, like the 

 interossei in the hand. Seven in number, there are three plantar and four 

 dorsal ; and two are found in each space, except the innermost. 



The plantar interossei^ o, belong to three outer metatarsal bones (fig. 

 213), and are slender fleshy slips. They arise from the under and inner 



