The subclavian ar-pert having left the thorax immediately above the first rib, in the interstice between the portions of the scalenus muscle, there receives the name axillary, because it passes under the axilla. This axillary artery detaches the external mammary arteries to the breast; and lies behind, on the inside of the coraco brachiaeus: when it has got to the under side of the subscapularis, it gives off a branch to that muscle, the serratus major anticus, etc. The axillary artery gives off the inferior scapular, which passes backwards, chiefly to the infra spinatus. Just below the head of the humerus, the axillary throws off the humeral or articular artery, which, passing round the joint, anastomoses with its fellow. The axillary artery commonly runs down behind the tendon of the pectoralis major, then passes over the coraco brachiaeus, goes down on the inside more and more forward, just covered by the inner edge of the biceps, passes under the aponeurosis of that muscle; and a little below the bend of the arm, between the pronator teres and supinator radii longus, divides into the radial and ulnar arteries.