This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
In withdrawing a blood sample from the median cubital vein the needle passes slightly deep and medial; which nerve might possibly be injured? 
Select and explain. 
A. Dorsal ulnar cutaneous, B. Lateral antebrachial cutaneous, C. Medial antebrachial cutaneous, D. Posterior antebrachial cutaneous
C: Medial antebrachial cutaneous
Answer: C: Medial antebrachial cutaneous 
Explanation: 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.