Hand and wrist anatomy, illustration. Dorsum of the hand showing superficial venous drainage. At the wrist the cephalic vein is on the thumb side and the basilic vein is opposite passing around to the flexor aspect. Tendons of extensor digitorum muscle pass into the hand deep to a band of connective tissue termed the extensor retinaculum. Cutaneous branches of the radial nerve and ulnar nerve are seen respectively on the thumb and little finger aspect. From Lizars, J. 1823 A system of anatomical plates of the human body. W. H.Lizars, Edinburgh.