In withdrawing a blood sample from the median cubital vein the needle passes slightly deep and medial; which nerve might possibly be injured?

The medial antebrachial cutaneous nerve is a direct branch from the medial cord of the brachial plexus. Since it provides cutaneous sensation to the medial side of the anterior forearm, it is slightly medial to the medial cubital vein and could be injured by a needle. If the needle had gone laterally, it might have injured the lateral antebrachial cutaneous nerve, which is running down the lateral side of the anterior forearm. This nerve is a branch of the musculocutaneous nerve. The posterior antebrachial cutaneous nerve runs on the posterior surface of the arm. It comes from the radial nerve. The dorsal ulnar cutaneous nerve is the nerve which runs on the dorsal side of the hand, providing cutaneous innervation to the ulnar side of the wrist, hand, and the medial 1.5 fingers. Finally, the superficial radial nerve innervates the dorsum of the radial side of the hand.