Question

Production of action potentials due to voltage-gated ion channels Fill in the appropriate word or term for the following statements describing how the action of voltage-gated channels produce action potentials.

1. The membrane is at the____ potential, occasionally generating graded potentials.

Answer 1

The membrane potential is at the resting potential and occasionally generates graded potentials due to voltage-gated ion channels. When depolarization occurs, Na+ channels open and Na+ ions rush into the cell, reducing the membrane potential. After repolarization, a new action potential can be generated once the Na+ channel returns to its resting state.

Step-by-step explanation:

The membrane potential is at the resting potential when it is not being stimulated. At this state, the membrane occasionally generates graded potentials, which are temporary changes in the membrane voltage caused by stimuli. Graded potentials can be either depolarization or hyperpolarization, depending on the specific ion channels activated in the cell membrane.

When a stimulus causes depolarization of the membrane, voltage-gated Na+ channels open and Na+ ions rush into the cell, reducing the membrane potential from its resting state. If this depolarization reaches a high enough level, voltage-gated K+ channels will open, allowing K+ ions to rush into the cell and restore the resting potential.

During an action potential, the voltage-gated Na+ channel is temporarily inactivated, preventing the generation of additional action potentials. Once the Na+ channel returns to its resting state, a new action potential can be generated, but it requires a stronger stimulus to overcome the K+ ions leaving the cell.