THE BRACHIAL ARTERY: BRANCHES. 777 



In ligation at the lower third — above the bend of the elbow — the inner edge 

 of the biceps tendon should be distinctly recognized, and the position of the 

 superficial veins, especially the median basilic, should be made apparent by com- 

 pression above. 



The incision should lie just within the edge of the tendon and should be parallel 

 with it, running therefore obliquely from within outward. It will usually be just 

 outside of the median basilic vein. Its centre is about on a level with the transverse 

 fold of the bend of the elbow. The fibres of the bicipital fascia are divided in the 

 line of the skin incision, — i.e., diagonally, as they run downward and inward. The 

 needle may be passed from within outward so as to avoid the median nerve, which, 

 however, is here some distance to the inner side. In all ligations of the brachial, its 

 frequent variations {vide supra) should be remembered, and the possibility of the 

 presence of a " vas aberrans' ' or an " accessory ulnar' ' should be borne in mind, as 

 should the occasional occurrence of a muscular slip crossing the vessel and derived 

 from the pectoralis major or from one of the humeral muscles. 



The collateral circulation is carried on after ligation above the superior profunda 

 between the ascending or recurrent branches of that vessel and the circumflex ( espe- 

 cially the posterior) and subscapular arteries. After ligation below the origin of the 

 inferior profunda, the circulation is carried on through the anastomosis between the 

 branches of the profunda from above and those of the anastomotic and the recurrents 

 from the radial, ulnar, and posterior interosseous from below. After ligation below 

 the anastomotic, the branches of that vessel, as well as those of the profundae, carry 

 the blood to the recurrents. 



1. The Superior Profunda Artery. — The superior profunda (a. profunda 

 brachii) (Fig. 709) arises from the upper part of the brachial, on its posterior surface, 

 and is directed downward and outward, between the inner and long heads of the 

 triceps, to reach the posterior surface of the humerus. Accompanied by the musculo- 

 spiral nerve, it curves around to the outer surface of the bone, lying in the musculo- 

 spiral groove, and having arrived at the external supracondylar ridge, it pierces the 

 external intermuscular septum and continues downward between the brachialis anticus 

 and the supinator longus, to terminate by anastomosing in front of the external 

 condyle with the radial recurrent artery. 



Brjinches. — In its course the superior profunda gives oflF a number of branches, among 

 which may be mentioned : 



(a) A deltoid branch (ramus deltoideus), which passes transversely outward to the inser- 

 tion of the deltoid, and then bends upward in the substance of that muscle. 



{b) Muscular branches to the triceps. 



(f ) A median cpUateral branch (a collateralis media), which passes downward in the sub- 

 stance of the inner head of the triceps to the olecranon process, where it anastomoses with the 

 posterior ulnar recurrent, the posterior interosseous recurrent, and the anastomotica magna. 



{d) An articular branch, which is given off from the lower portion of the artery, just before 

 it pierces the external intermuscular septum, and is distributed to the elbow-joint. 



{e) Cutaneous branches, which accompany the external cutaneous branches of the mus- 

 culo-spiral nerve. 



Variations. — The superior profunda occasionally arises from the axillary artery either 

 directly or in common with the posterior circumflex. That portion of its main stem which 

 traverses the musculo-spiral groove beyond the point where the medial collateral branch is given 

 off is sometimes termed the radial collateral the profunda being regarded as dividing, after 

 a short course, into the two collateral branches. The deltoid artery not infrequently arises 

 directly from the brachial artery or else from the inferior profunda. 



2. The Inferior Profunda Artery. — The inferior profunda (a. collateralis 

 ulnaris superior) ( Fig. 709) arises from the inner surface of the brachial, at about the 

 middle of its course. It passes downward and backward, accompanying the ulnar 

 nerve, through the internal intermuscular septum, and then downward along the 

 anterior surface of the inner head of the triceps to the back of the internal condyle, 

 where it terminates by anastomosing with the anastomotica magna and the posteric' 

 ulnar recurrent. It gives branches to the triceps and to the brachialis anticus. 



