Counting the axillary nerve, which is not truly in the axilla, there are seven peripheral nerves in the axilla that arise from the brachial plexus. These are the medial cutaneous nerves to the arm and the forearm, the ulnar nerve, which arises from the medial cord, the median nerve, which comes from the medial and lateral cords, the radial nerve, which arises from the posterior cord, and the musculocutaneous nerve, which originates from the lateral cord. These nerves and their areas of sensory distributions are discussed in this chapter. The intercostobrachial nerve, which does not originate from the brachial plexus, arises from the first and second thoracic spinal root and innervates the skin in the medial upper arm and axilla. The motor functions of these nerves are discussed in Chapter 9.
Keywords: Acute pain medicine, Axilla, Axilla borders, Axillary artery, Axillary nerve, Brachial artery, Brachial plexus, Brachial vein, Intercostobrachial nerve, Lateral cord, Medial cord, Medial cutaneous nerve of the forearm, Medial cutaneous nerves of the arm, Median nerve, Musculocutaneous nerve, Posterior cord, Radial nerve, Regional anesthesia, Second thoracic spinal root, Ulnar nerve.