Displacement of stereocilia toward the kinocilium of a hair cell
(a) Produces a depolarization of the membrane
(b) Produces a hyperpolarization of the membrane
(c) Decreases the membrane permeability to sodium ions
(d) Increases the membrane permeability to potassium ions
(e) Does not affect the membrane potential of the cell

Verified step by step guidance

1. Understand the structure of hair cells in the inner ear, specifically the role of stereocilia and the kinocilium in mechanotransduction.
2. Recognize that displacement of stereocilia toward the kinocilium causes mechanically gated ion channels to open.
3. Identify which ions flow through these channels; in hair cells, potassium ions (K+) from the endolymph enter the cell due to the high K+ concentration outside.
4. Understand that the influx of K+ ions depolarizes the hair cell membrane, making the inside more positive.
5. Conclude that displacement of stereocilia toward the kinocilium increases membrane permeability to potassium ions and produces depolarization of the membrane.

Key Concepts

Structure and Function of Hair Cells

Hair cells are sensory receptors in the inner ear that detect mechanical stimuli through their stereocilia. The kinocilium is a specialized, taller cilium that helps determine the direction of stereocilia displacement, which influences the cell's electrical response.

Mechanotransduction in Hair Cells

Displacement of stereocilia toward the kinocilium opens mechanically gated ion channels, allowing ions to flow into the hair cell. This process converts mechanical movement into an electrical signal, typically leading to depolarization when channels open.

Ion Permeability and Membrane Potential Changes

In hair cells, potassium ions (K+) from the endolymph enter through open channels during stereocilia deflection toward the kinocilium, increasing membrane permeability to K+ and causing depolarization. This depolarization triggers neurotransmitter release and signal transmission.