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.
