566 THE ARTERIES. 



turning round the oblique flexor of the fore-arm, along with the radial 

 nerve, and reaching beneath the short extensor, to descend, still with its 

 satellite nerve, in front of the articulation of the elbow, where this branch 

 anastomoses with the anterior radial artery ; it supplies all the olecranian 

 muscles, except the long extensor, as well as the oblique flexor of the fore- 

 arm and the anterior extensor of the metacarpus. 



3. Epicondyloid, internal collateral of the elbow, or ulnar artery. 

 Smaller than the external collateral, this artery arises at the nutrient 

 foramen of the humerus, and proceeds backwards on the internal face of 

 that bone, to pass beneath the long extensor of the fore-arm, by following in 

 a more or less flexous manner the inferior border of the middle extensor ; 

 it then descends, at first behind the epicondyle, then on the fore-arm, which 

 it passes along for its whole length, underneath the aponeurotic sheath of 

 this region, between the oblique and the external flexor of the metacarpus, 

 accompanied by the ulnar vein and nerve of the same name, and the tendon 

 of the ulnar portion of the perforans muscle. Arriving near the carpus, 

 this long branch anastomoses by inosculation with a branch from the 

 posterior radial artery. 



In its antibrachial course, this artery only gives off very attenuated 

 branches, whose study is of little importance. But before attaining the 

 fore-arm, it furnishes : 1, The nutrient artery of the humerus ; 2, Articular 

 ramuscules ; 3, More or less voluminous muscular branches, particularly 

 for the long extensor of the fore-arm, the middle extensor, and the sterno- 

 aponeuroticus : those which arrive in the latter muscle traverse it only to 

 become subcutaneous alternately ; one of them accompanies the principal 

 superficial vein of the fore-arm, and sends ramuscules into the bend of the 

 elbow. Eegular in their distribution, these different arteries present 

 numerous varieties of origin, among which it is difficult to distinguish the 

 most constant disposition. The last-mentioned vessel and the nutrient 

 artery of the humerus, often emanate directly from the humeral trunk. 



4. Principal artery of the biceps, or coraco-radialis artery. This 

 originates a little below or above the preceding ; opposite to, or in front of 

 it, it usually divides into two branches : one ascending, the other descending, 

 which enter the substance of the muscle. 



1. Anterior Radial Artery. (Fig. 348, A.) 



The anterior radial artery, 1 the smallest of the two terminal branches of 

 the humeral, separates itself at an acute angle from the posterior artery, 

 above the articular condyle of the humerus. It descends on the anterior 

 face of the ulnar articulation, passing beneath the inferior extremity of the 

 flexor muscles of the fore-arm and the superior extremity of the principal 

 extensor of the metacarpus, where it meets the radial nerve ; in company 

 with this nerve it extends on the anterior face of the radius, below the 

 anterior extensor muscle of the phalanges, to the knee, where it becomes 

 very thin and breaks up into several ramuscules, which are continued on 

 the capsular ligament of the carpal articulations, after anastomosing on 

 the inner side with the divisions of a branch furnished by the posterior 

 radial artery, and on the outside with the ramifications from the interosseous 

 artery of the fore-arm. 



1 In Man this artery is absent, or rather it is represented by an insignificant 

 muscular twig. 



