Arm nerves. Historical anatomical artwork of the nerves (white) of the rear (top side) of a human forearm. At left, the superficial (surface) nerves are shown, while at right the deep nerves, muscles (red) and bones (yellow) are seen. Even though the surface muscles and connective tissue have been removed, there are few nerves on this side of the arm. The nerves are mainly on the other side of the arm. Many tendons and ligaments (grey) are seen in the wrist and hand. The superficial arm nerves are the internal and external cutaneous (skin) nerves. Artwork from The Nerves of the Human Body (Ed. Jones Quain, London, 1839).