SURGICAL ANATOMY OF BRACIIIAL ARTERY. 409 



the artery should be separated from its accompanying veins and secured. In this situation the 

 inferior profunda may be mistaken for the main trunk, especially if enlarged, from the collateral 

 circulation having become established ; this may be avoided by directing the incision externally 

 towards the Biceps rather than inwards or backwards towards the Triceps. 



The lower part of the brachial artery is of extreme interest in a surgical point of view, on ac- 

 count of the relation which it bears to those veins most commonly opened in venesection. Of 

 these vessels, the median basilic is the largest and most prominent, and, consequently, the one 

 usually selected for the operation. It should be remembered, that this vein runs parallel with 

 the brachial artery, from which it is separated by the bicipital fascia, and that in no case should 

 this vessel be selected for venesection, except in a part which is not in contact with the artery. 



Collateral Circulation. After the application of a ligature to the brachial artery in the upper 

 third of the arm, the circulation is carried on by branches from the circumflex and subscapular 

 arteries, anastomosing with ascending branches from the superior profunda. If the brachial is 

 tied below the origin of the profunda arteries, the circulation is maintained by the branches of the 

 profundae, anastomosing with the recurrent radial, ulnar, and interosseous arteries. In two cases 

 described by Mr. South, 1 in which the brachial artery had been tied some time previously, in one 

 "a long portion of the artery had been obliterated, and sets of vessels are descending on either 

 side from above the obliteration, to be received into others which ascend in a similar manner 

 from below it. In the other, the obliteration is less extensive, and a single curved artery about 

 as big as a crow-quill passes from the upper to the lower open part of the artery." 



The branches of the brachial artery are the 



Superior profunda. Inferior profunda. 



Nutrient artery. Auastomotica magna. 



Muscular. 



The superior profunda arises from the inner and back part of the brachial, 

 opposite the lower border of the Teres major, and passes backwards to the 

 interval between the outer and inner heads of the Triceps muscle, accompanied 

 by the musculo-spiral nerve ; it winds round the back part of the shaft of the 

 humerus in the spiral groove, between the Triceps and the bone, and descends on 

 the outer side of the arm to the space between the Brachialis anticus and 

 Supinator longus, as far as the elbow, where it anastomoses with the recurrent 

 branch of the radial artery. It supplies the Deltoid, Coraco-brachialis, and 

 Triceps muscles, and whilst in the groove, between the Triceps and the bone, it 

 gives off the posterior articular artery, which descends perpendicularly between 

 the Triceps and the bone, to the back part of the elbow-joint, where it anastomo- 

 ses with the interosseous recurrent branch, and, on the inner side of the arm, 

 with the posterior ulnar recurrent, and with the anastomotica magna or inferior 

 profunda (fig. 221). 



The nutrient artery of the shaft of the humerus arises from the brachial, about 

 the middle of the arm. Passing downwards, it enters the nutritious canal of that 

 bone, near the insertion of the Coraco-brachialis muscle. 



The inferior profunda, of small size, arises from the brachial, a little below the 

 middle of the arm ; piercing the internal intermuscular septum, it descends on the 

 surface of the inner head of the Triceps muscle, to the space between the inner 

 condyle and olecranon, accompanied by the ulnar nerve, and terminates by anas- 

 tomosing with the posterior ulnar recurrent, and anastomotica magna. 



The anastomotica magna arises from the brachial, about two inches above the 

 elbow-joint. It passes transversely inwards upon the Brachialis anticus, and, 

 piercing the internal intermuscular septum, winds round the back part of the 

 humerus, between the Triceps and the bone, forming an arch above the olecranon 

 fossa, by its junction with the posterior articular branch of the superior profunda. 

 As this vessel lies on the Brachialis anticus, an offset passes between the internal 

 condyle and olecranon, which anastomoses with the inferior profunda and pos- 

 terior ulnar recurrent arteries. Other branches ascend to join the inferior pro- 

 funda ; and some descend in front of the inner condyle, to anastomose with the 

 anterior ulnar recurrent. 



The muscular are three or four large branches, which, are distributed to the 



1 CHELINS'S Surgery, p. 254. 



