The stapes (Latin stirrup) is the smallest ossicle. It has a head, two limbs, and a base. Its head, directed laterally, articulates with the incus. The base (footplate) of the stapes fits into the oval window on the medial wall of the tympanic cavity. The oval base is attached to the margins of the oval window. The base of the stapes is considerably smaller than the tympanic membrane; as a result, the vibratory force of the stapes is increased approximately 10 times over that of the tympanic membrane. Consequently, the auditory ossicles increase the force but decrease the amplitude of the vibrations transmitted from the tympanic membrane through the ossicles to the internal ear.