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
Ulnar artery below the elbow, but more frequently higher, the brachial being more often the source of origin than the axillary. Variations in the position of this vessel are more common than in the radial. When its origin is normal, the course of the vessel is rarely changed. When it arises high up, it is almost invariably superficial to the Flexor muscles in the forearm, lying commonly beneath the fascia, more rarely between the fascia and integument. In a few cases, its position is subcutaneous in the upper part of the forearm, and subaponeurotic in the lower part. Ulnar artery The ulnar