Which arrangement of the auditory ossicles correctly describes the sequence from the eardrum to the inner ear?

• A. Malleus, incus, tympanic membrane
• B. Pinna, tympanic membrane, ossicles
• C. Malleus, incus, stapes
• D. Malleus, incus, stapes

Answer: (D)

Vibrations travel through a chain of tiny bones that transmit sound from the eardrum into the inner ear. The first bone is the malleus, which is directly attached to the tympanic membrane (eardrum) and picks up its vibrations. It passes them to the incus, which then transfers the motion to the stapes. The stapes, in turn, presses on the oval window to send the vibrations into the fluid-filled inner ear. So the correct sequence is malleus, incus, stapes. Including the tympanic membrane in the sequence isn’t a description of the ossicles themselves, and the ossicles must be described in the order they relay the vibration to the inner ear.