Fig. 3. Brachial plexus. A in The Nerve Bundle via the Median Nerve Innervating the Ulnar Intrinsic Muscles of the Hand in a Gorilla Equivalent to the Deep Branch of the Ulnar Nerve in the Human

Fig. 3. Brachial plexus. A. The brachial plexus is composed of the upper trunk·C4, C5 and C6 roots, the middle trunk·C7 root and the lower trunk·C8 root. B. The subclavian artery was found to split the middle trunk into two bundles: upper and lower. The upper bundle consists of the anterior and posterior divisions, and the lower bundle is the medial division (Eisler) going to the medial cord.