182 



DISSECTION OF THE LEG. 



course and 

 extent ; 



direction ; 



relations to 

 parts 

 aronnd ; 



position of 

 veins 



and nerve ; 



branches : 



Muscular. 



Cutaneous. 



Recurrent. 



Superior 

 libular. 



Malleolar: 



internal and 

 external. 



Dorsal 

 artery : 



extent and 

 course ; 



relations ; 



The course of the artery is forwards through the aperture in the 

 upper part of the interosseous membrane, along the front of that 

 membrane, and over the tibia to the foot. A line drawn along the 

 front of the leg from a point midway between the projection of the 

 outer tuberosity of the tibia and the head of the fibula to the centre 

 of the ankle will mark the position of the vessel. 



For a short distance (about two inches) the artery lies between 

 the tibialis anticus and the extensor longus digitorum ; afterwards 

 it is placed between the tibial muscle and the extensor proprius 

 hallucis as far as the lower third of the leg, where the last muscle 

 becomes superficial and crosses over the vessel to its inner side. The 

 vessel rests on the interosseous membrane in two-thirds of its extent, 

 being overlapped by the fleshy bellies of the contiguous muscles, so 

 that it is at some depth from the surface ; but it is placed in front 

 of the tibia and the ankle-joint in the lower third, and is there 

 comparatively superficial between the tendons of the muscles. 



Venae comites entwine around the artery, covering it very closely 

 with cross branches in the upper part. The anterior tibial nerve 

 approaches the tibial vessels from the outer side in the tipper third 

 of the leg, and continues with them, lying along their anterior 

 aspect to their lower end, where it is again on the outer side. 



BRANCHES. In its course along the front of the leg the anterior 

 tibial artery furnishes numerous muscular and cutaneous branches ; 

 and near the knee and ankle the following named branches take 

 origin : 



a. The anterior tibial recurrent artery is given off as soon as 

 the vessel appears through the interosseous membrane, and ascend- 

 ing through the tibialis anticus, ramifies over the outer tuberosity 

 of the tibia, where it anastomoses with the other articular arteries. 



b. The superior fibular branch runs upwards through the highest 

 part of the extensor longus digitorum to the superior tibio-fibular 

 articulation, to which, with the neighbouring parts, it is dis- 

 tributed. 



c. Malleolar branches (internal and external) arise near the ankle- 

 joint, and are distributed over the ends of the tibia and fibula. The 

 internal is the smaller, and less constant in origin ; it anastomoses 

 with twigs of the posterior tibial artery. The external communi- 

 cates with the anterior peroneal artery (fig. 70), which comes 

 through from the back between the tibia and fibula just above the 

 lower tibio-fibular articulation and will be found to be one of the 

 terminal branches of the peroneal artery (p. 196). 



The DORSAL ARTERY OP THE FOOT (fig. 70) is the continuation of 

 the anterior tibial, and extends from the front of the ankle-joint to 

 the upper part of the first interosseous space : at this interval it 

 passes downwards between the heads of the first dorsal interosseous 

 muscle, to end in the sole, where it will be subsequently examined 

 (p. 208). 



The artery rests on the inner part of the tarsus, viz., the astra- 

 galus, the navicular, and middle cuneiform bones ; and it is covered 

 by the integuments and the deep fascia, and by the inner piece of 



