Which of the sequence of events below best describes how hair cells sterocilia) in the rabbit ear provide the brain with information about stimulus intensity?

Question

Quizplus · Accepted Answer

Hair cells (stereocilia) are activated by bending of their hair-like extensions in response to sound waves or other stimuli. When stereocilia bend in one direction, potassium (K+) enters the hair cell through mechanically-gated ion channels, leading to depolarization of the membrane potential. This depolarization then triggers the opening of voltage-gated calcium (Ca2+) channels, resulting in the release of neurotransmitter (glutamate) from the hair cell onto the afferent neuron. In turn, this results in the generation of action potentials in the afferent neuron that transmit information about the stimulus to the brain. The greater the degree of hair cell bending, the greater the depolarization and the higher the frequency of action potentials generated in the afferent neuron. Therefore, choice B is the correct sequence of events because strong wind bends the hair, leading to depolarization, high concentration of neurotransmitter released, and high frequency of action potentials in the afferent neuron to the brain.

Which of the Sequence of Events Below Best Describes How