stapes bone

The stapes or stirrup is the stirrup-shaped small bone or ossicle in the middle ear which is attached to the incus laterally and to the fenestra ovalis, the 'oval window' medially. The oval window is adjacent to the vestibule of the inner ear. The stapes is the smallest and lightest bone in the human body. The stapes transmits the sound vibrations from the incus to the membrane of the inner ear inside the fenestra ovalis. The stapes is also stabilized by the stapedius muscle, which is innervated by the facial nerve. In non-mammalian vertebrates, the bone homologous to the stapes is usually called the columella; however, in reptiles, either term may be used[WP,unvetted].