[The stapedius muscle--the present opinions about anatomy and physiology]

Abstract

The authors present current opinions about anatomy and physiology of the stapedius muscle and its role of the hearing process. The stapedius muscle is the smallest striped muscle of the human body and contracts reflexive in response to acoustic stimulation. The stapedius muscle puls the neck of the stapes in the direction of the stapedius tendon. This movement causes stiffening of the incus and the malleus and also changes the pressure of the perilymph in the inner ear. This is the protective inner ear action of the stapedius reflex against hearing damage by noise. The stapedius reflex shows bilateral interactions and its center is located in the brainstem. The binaural interaction of the stapedius reflex plays an important role in the maintaining of the sound direction. The stapedius tendon also plays role in the vascularization of the long process of the incus.