(le-vā'tŏr kos-tā'rūm mŭs'ĕlz) Muscle of thorax; origin, tips of transverse processes of C7 and T1-T11 vertebrae; insertion, ribs, between tubercle and angle; action, elevate ribs for deep inspiration; nerve, dorsal rami of C8-T11 spinal nerves. Synonym(s): elevator muscle of rib, musculi levatores costarum.