What are the ossicles?

What are the ossicles?

• A. The vestibular organs in the inner ear.
• B. Three small bones in the middle ear that transmit sound vibrations.
• C. The three layers of the tympanic membrane.
• D. The sensory cells in the organ of Corti.

Answer: (B)

The main concept here is the middle ear ossicles—the three tiny bones that transmit and amplify sound from the eardrum into the inner ear. These are the malleus (hammer) attached to the tympanic membrane, the incus (anvil) linking the two, and the stapes (stirrup) pressing on the oval window of the cochlea. Together they form the ossicular chain, converting the ear’s vibrating eardrum into mechanical energy that can move the fluid-filled inner ear. This system also provides impedance matching, using a lever action and a larger tympanic membrane area relative to the tiny oval window to help transfer sound efficiently into the inner ear. The other structures mentioned don’t fit as ossicles: the vestibular organs are involved in balance, not hearing; the three layers of the tympanic membrane describe its tissue structure, not a chain of bones; and the sensory cells in the organ of Corti are hair cells that transduce mechanical energy into neural signals, not bones in the middle ear.

The main concept here is the middle ear ossicles—the three tiny bones that transmit and amplify sound from the eardrum into the inner ear. These are the malleus (hammer) attached to the tympanic membrane, the incus (anvil) linking the two, and the stapes (stirrup) pressing on the oval window of the cochlea. Together they form the ossicular chain, converting the ear’s vibrating eardrum into mechanical energy that can move the fluid-filled inner ear. This system also provides impedance matching, using a lever action and a larger tympanic membrane area relative to the tiny oval window to help transfer sound efficiently into the inner ear.

The other structures mentioned don’t fit as ossicles: the vestibular organs are involved in balance, not hearing; the three layers of the tympanic membrane describe its tissue structure, not a chain of bones; and the sensory cells in the organ of Corti are hair cells that transduce mechanical energy into neural signals, not bones in the middle ear.