The hand consists of five digits made up of 19 bones and 19 joints. The document discusses the carpalmetacarpal joints of the fingers, which are the articulations between the distal carpal row and the bases of the second through fifth metacarpals. These joints are supported by strong transverse and weaker longitudinal ligaments. The deep transverse metacarpal ligament spans the heads of the second through fourth metacarpals and prevents abduction at the joints. The carpal bones form a volar concavity that contributes to the arches of the palm and forms the carpal tunnel, which contains tendons and the median nerve.