In all cases, the radial artery ran the same course. It passed through the floor of the anatomical snuffbox under the first and third extensor compartments and gave rise to the first dorsal metacarpal artery at the bony apex of the first web space. The radial artery traveled distally over or radial to the second metacarpal bone. The first dorsal metacarpal artery was not involved in the irrigation of the thumb in any hand. In each dissection,the radial artery continued to the first intermetacarpal space, where it penetrated the palmar space at the distal border of the base of the