axillary nerve, one of the last two branches of the posterior cord of the brachial plexus before the posterior cord becomes the radial nerve. It divides into a posterior branch and an anterior branch. The posterior branch innervates the teres minor, part of the deltoideus, and part of the skin overlying the deltoideus; the anterior branch innervates the deltoideus. Some fibers of the nerve also supply the capsule of the shoulder joint.
