Median nerve and medial cords of the brachial plexus, courses through the anterior part of arm, forearm, and hand, and terminates by supplying the muscles of the hand. After receiving inputs from both the lateral and medial cords of the brachial plexus, the median nerve enters the arm from the axilla at the inferior margin of the teres major muscle. It then passes vertically down and courses lateral to the brachial artery between biceps brachii (above) and brachialis (below). At first, it is lateral to the artery and lies anterior to the elbow joint; it then crosses anteriorly to run medial to
Subclavian artery muscle; above, the brachial plexus of nerves; below, the pleura. The subclavian vein lies below and in front of the artery, separated from it by the Scalenus anterior. The third portion of the subclavian artery runs downward and lateralward from the lateral margin of the Scalenus anterior to the outer border of the first rib, where it becomes the axillary artery. This is the most superficial portion of the vessel, and is contained in the subclavian triangle. It is covered, in front, by the skin, the superficial fascia, the Platysma, the supraclavicular nerves, and the deep cervical fascia. The external