Question

How does the up and down motion of the basilar membrane activate the hair cells?

a. Hair cells are responsible for converting mechanical vibration into neural activity.
b. Basilar membrane vibrations directly trigger auditory nerve signals.
c. Hair cells play no role in the activation of the basilar membrane.
d. Basilar membrane movements create a visual response in the eye.

Answer 1

The motion of the basilar membrane bends stereocilia on hair cells, triggering neurotransmitter release and action potentials that travel to the brain via the auditory nerve. The place theory explains how different frequencies affect specific regions of the basilar membrane, leading to sound perception.

Step-by-step explanation:

The up-and-down motion of the basilar membrane activates hair cells by causing the stereocilia that are attached to the tectorial membrane to bend. This bending leads to the release of neurotransmitters at a synapse, which in turn triggers action potentials in sensory neurons. These action potentials are then sent to the brain via the auditory nerve, resulting in the perception of sound. The specific activation of hair cells along the length of the basilar membrane, by sound waves of different frequencies, is explained by the place theory, which associates different sound frequencies with specific regions of the basilar membrane.