Describe the steps involved in the generation of an action potential.

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Step 1: Resting membrane potential is established, typically around -70 mV, due to the distribution of ions (mainly Na\(\textsuperscript{+}\) and K\(\textsuperscript{+}\)) across the neuron's membrane and the activity of the sodium-potassium pump.

Step 2: A stimulus causes the membrane potential to reach the threshold level (usually around -55 mV), triggering the opening of voltage-gated sodium (Na\(\textsuperscript{+}\)) channels.

Step 3: Rapid depolarization occurs as Na\(\textsuperscript{+}\) ions rush into the cell, making the inside of the neuron more positive.

Step 4: At the peak of the action potential, voltage-gated sodium channels close and voltage-gated potassium (K\(\textsuperscript{+}\)) channels open, allowing K\(\textsuperscript{+}\) ions to exit the cell, initiating repolarization.

Step 5: The membrane potential returns toward the resting level (repolarization), sometimes overshooting to cause hyperpolarization, before the sodium-potassium pump and leak channels restore the resting membrane potential.

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Resting Membrane Potential

The resting membrane potential is the electrical charge difference across the neuron's membrane when it is not transmitting a signal, typically around -70 mV. It is maintained by ion gradients, primarily through the sodium-potassium pump and selective permeability to ions, setting the stage for action potential initiation.

Depolarization and Threshold

Depolarization occurs when a stimulus causes the membrane potential to become less negative, reaching a critical threshold (usually around -55 mV). This triggers voltage-gated sodium channels to open, allowing Na+ ions to rush into the cell, initiating the rising phase of the action potential.

Repolarization and Hyperpolarization

After the peak of the action potential, voltage-gated sodium channels close and potassium channels open, allowing K+ to exit the cell, restoring the negative membrane potential (repolarization). Sometimes, the membrane potential becomes more negative than resting level (hyperpolarization) before stabilizing back to resting potential.