DORSALIS PEDIS. 449 



PLAN OF THE KELATIONS OF THE DORSALIS PEDIS ARTERY. 



In front. 



Integument and fascia. 

 Innermost tendon of Extensor brevis digitorum. 



Tibial side. f \ Fibular side. 



Extensor proprius pollicis. f nopslllls \ Extensor longus digitorum 



Anterior tibial nerve. 



Behind. 

 Astragalus. 

 Scaphoid. 

 Internal cuneiform. 

 Their ligaments. 



Peculiarities in Size. The dorsal artery of the foot may be larger than usual, to compensate 

 for a deficient plantar artery ; or it may be deficient in its terminal branches to the toes, which 

 are then derived from the internal plantar ; or its place may be supplied altogether by a large 

 anterior peroneal artery. 



Position. This artery frequently curves outwards, lying external to the line between the 

 middle of the ankle and the back part of the first interosseous space. 



Surgical Anatomy. This artery may be tied, by making an incision through the integument, 

 between two and three inches in length, on the fibular side of the tendon of the Extensor pro- 

 prius pollicis, in the interval between it and the inner border of the short Extensor muscle. The 

 incision should not extend further forwards than the back part of the first interosseous space, as 

 the artery divides in this situation. The deep fascia being divided to the same extent, the artery 

 will be exposed, the nerve lying upon its outer side. 



Branches. The branches of the dorsalis pedis are the 



Tarsea. . Interossese. 



Metatarsea. Dorsalis hallucis. 



Communicating. 



The tarsea artery arises from the dorsalis pedis, as that vessel crosses the sca- 

 phoid bone ; it passes in an arched direction outwards, lying upon the tarsal bones, 

 and covered by the Extensor brevis digitorum ; it supplies that muscle and the 

 articulations of the tarsus, and anastomoses with branches from the metatarsea, 

 external malleolar, peroneal, and external plantar arteries. 



The metatarsea arises a little anterior to the preceding ; it passes outwards to 

 the outer part of the foot, over the bases of the metatarsal bones, beneath the 

 tendons of the short Extensor, its direction being influenced by its point of 

 origin ; and it anastomoses with the tarsea and external plantar arteries. This 

 vessel gives off' three branches, the interossese, which pass forwards upon the 

 three outer Dorsal interossei muscles, and, in the clefts between the toes, divide 

 into two dorsal collateral branches for the adjoining toes. At the back part of 

 each interosseous space these vessels receive the posterior perforating branches 

 from the plantar arch ; and at the fore part of each interosseous space, they are 

 joined by the anterior perforating branches from the digital arteries. The outer- 

 most interosseous artery gives off a branch which supplies the outer side of the? 

 little toe. 



The dorsalis hallucis runs forwards along the outer border of the first meta- 

 tarsal bone, and, at the cleft between the first and second toes, divides into two 

 branches, one of which passes inwards, beneath the tendon of the Flexor longus 

 pollicis, and is distributed to the inner border of the great toe ; the other branch 

 bifurcating to supply the adjoining sides of the great and second toes. 



The communicating artery dips down into the sole of the foot, between the .two 

 heads of the first Dorsal interosseous muscle, and inosculates with the termination 

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