Question

The transduction of sound waves into action potentials occurs

(A) in the tectorial membrane as it is stimulated by hair cells.

(B) when hair cells are bent against the tectorial membrane, causing them to depolarize and release neurotransmitter that stimulates sensory neurons.

(C) as the basilar membrane vibrates at different frequencies in response to the varying volume of sounds.

(D) within the middle ear as the vibrations are amplified by the malleus, incus, and stapes.

Short answer

(A) The statement “in the tectorial membrane as it is stimulated by hair cells” isfalse.

(B) The statement “when hair cells are bent against the tectorial membrane, causing them to depolarize and release neurotransmitter that stimulates sensory neurons” istrue.

(C) The statement “as the basilar membrane vibrates at different frequencies in response to the varying volume of sounds” isfalse.

(D) The statement “within the middle ear as the vibrations are amplified by the malleus, incus, and stapes” is false.

Step-by-step solution

The sense of hearing

The sense of hearing is one of the five senses that can be detected by the body. Hearing is regulated by the ears. This sensory information of the sound signals helps in understanding the surrounding environment in a better way. The ears have special receptors for converting sound into action potentials.

Explanation of option ‘(A)’

The tectorial membrane is one of the components of the inner ear and is an extracellular matrix that surrounds the cochlea. Functionally, it is involved in regulating the levels of ions near the stereocilia.

Thus, action potentials are not produced due to the functioning of the tectorial membrane.

Therefore, the given statement is false.

Explanation of option ‘(B)’

The hair cells are the ears’ sensory receptors and are located within the cochlea. Functionally, the hair cells detect the sound signal and bend themselves in accordance with the strength of sound. This bending causes depolarization and release of neurotransmitters.

The molecules of neurotransmitters act upon the sensory neurons and generate an action potential in accordance with the sound signal.

Thus, the hair cell movements trigger the release of neurotransmitters and the generation of the action potential.

Therefore, the given statement is true.

Explanation of option ‘(C)’

The vibrations of the basilar membrane in accordance with the varying frequency of the sound helps in depolarizing the receptor cells of the ear, that is, the hair cells. The action potential is generated in response to the neurotransmitters released by the hair cells.

Thus, the basilar membrane vibration does not generate an action potential.

Therefore, the given statement is false.

Explanation of option ‘(D)’

The middle ear bones (stapes, incus, and malleus) are only involved in amplifying the incoming sounds from the outer ear and transmitting them forward towards the inner ear. Action potentials are generated within the inner ear region.

Thus, the bones of the middle ear only amplify the incoming sound.

Therefore, the given statement is false.