Which statement about the inner ear is true?

Which statement about the inner ear is true?

• A. The outer ear captures sound.
• B. The auditory ossicles reside in the inner ear.
• C. The cochlea transduces mechanical energy into electrical signals.
• D. The inner ear contains structures that transduce mechanical energy into neural signals.

Answer: (D)

Mechanical energy becomes neural information in the inner ear through hair cells that respond to vibrations and head movements. In the cochlea, the basilar membrane’s motion causes the hair cell stereocilia to bend, opening ion channels and creating a receptor potential. This electrical change triggers neurotransmitter release onto auditory nerve fibers, which then fire action potentials that travel to the brain. The vestibular organs in the inner ear use the same principle to sense balance, sending neural signals when the head moves. So, the inner ear contains structures that transduce mechanical energy into neural signals, covering both hearing and balance. Outer ear functions involve capturing sound, not transduction in the inner ear. The middle ear houses the auditory ossicles, which transmit vibrations but aren’t located in the inner ear. While hair cells do generate electrical signals, the key point is that these mechanical-to-neural signals travel via the auditory neurons, making the broader statement the most accurate descriptor.

Mechanical energy becomes neural information in the inner ear through hair cells that respond to vibrations and head movements. In the cochlea, the basilar membrane’s motion causes the hair cell stereocilia to bend, opening ion channels and creating a receptor potential. This electrical change triggers neurotransmitter release onto auditory nerve fibers, which then fire action potentials that travel to the brain. The vestibular organs in the inner ear use the same principle to sense balance, sending neural signals when the head moves. So, the inner ear contains structures that transduce mechanical energy into neural signals, covering both hearing and balance.

Outer ear functions involve capturing sound, not transduction in the inner ear. The middle ear houses the auditory ossicles, which transmit vibrations but aren’t located in the inner ear. While hair cells do generate electrical signals, the key point is that these mechanical-to-neural signals travel via the auditory neurons, making the broader statement the most accurate descriptor.