DORSALIS PEDIS. 529 



be separated from each other by the finger. The artery is then exposed, deeply seated, lying 

 upon the interosseous membrane, the nerve lying externally, and one of the venae comites on 

 either side ; these must be separated from the artery before the aneurism needle is passed round it. 



To tie the vessel in the lower third of the leg above the ankle-joint, an incision about three 

 inches in length should be made through the integument between the tendons of the Tibialis 

 Anticus and Extensor Proprius Pollicis muscles, the deep fascia being divided to the same 

 extent ; the tendon on either side should be held aside, when the vessel will be seen lying upon 

 the tibia, with the nerve superficial to it, and one of the venae comites on either side. 



In order to secure the artery over the instep, an incision should be made on the fibular side of 

 the tendon of the Extensor Proprius Pollicis, between it and the innermost tendon of the long 

 Extensor ; the deep fascia having been divided, the artery will be exposed, the nerve lying either 

 superficial to it, or to its outer side. 



The branches of the anterior tibial artery are, the 



Kecurrent tibial. Internal malleolar. 



Muscular. External malleolar. 



The recurrent branch arises from the anterior tibial, as soon as that vessel has 

 passed through the interosseous space ; it ascends in the Tibialis Anticus muscle, 

 and ramifies on the front and sides of the knee-joint, anastomosing with the 

 articular branches of the popliteal. 



The muscular branches are numerous ; they are distributed to the muscles 

 which lie on either side of the vessel, some piercing the deep fascia to supply 

 the integument, others passing through the interosseous membrane, and anas- 

 tomosing with branches of the posterior tibial and peroneal arteries. 



The malleolar arteries supply the ankle-joint. The internal arises about two 

 inches above the articulation, and passes beneath the tendon of the Tibialis 

 Anticus to the inner ankle, upon which it ramifies, anastomosing with branches 

 of the posterior tibial and internal plantar arteries. The external passes beneath 

 the tendons of the Extensor Longus Digitorum and Extensor Proprius Pollicis, 

 and supplies the outer ankle, anastomosing with the anterior peroneal artery, 

 and with ascending branches from the tarsal branch of the dorsalis pedis. 



DORSALIS PEDIS ARTERY. (Fig. 300.) 



The Dorsalis Pedis, the continuation of the anterior tibial, passes forwards 

 from the bend of the ankle along the tibial side of the foot to the back part of 

 the first interosseous space, where it divides into two branches, the dorsalis 

 hallucis and communicating. 



Relations. This vessel, in its course forwards, rests upon the astragalus, sca- 

 phoid, and internal cuneiform bones and the ligaments connecting them, being 

 covered by the integument and fascia, and crossed near its termination by the 

 innermost tendon of the Extensor Brevis Digitorum. On its tibial side is the 

 tendon of the Extensor Proprius Pollicis; on its jibular side, the innermost 

 tendon of the Extensor Longus Digitorum, and the termination of the anterior 

 tibial nerve. It is accompanied by two veins. 



PLAN OF THE EELATIONS OF THE DORSALIS PEDIS ARTERY. 



In front. 



Integument and fascia. 

 Innermost tendon of Extensor Brevis Digitorum. 



Tibial side. / \ Fibular side. 



Extensor Proprius Pollicis. Dorsalis Extensor Lomnis Didtorum. 



\ Pedis. i ,-, i 



Anterior tibial nerve. 



Behind. 

 Astragulus, 

 Scaphoid, 

 Internal cuneiform, 

 and their ligaments. 



