AP quick summary

What generally controls AP

Ion concentration gradients

Changes in membrane voltage

ion channels/transporters

What drives directional ion flow across the neuronal membrane?

Ion concentration gradients across the membrane.

What effect does the movement of ions across the membrane have?

It changes the membrane potential (voltage).

What happens when membrane potential changes reach above threshold?

An action potential (AP) is triggered to fire.

Which channels open during above-threshold changes, and what effect do they have?

Voltage-gated Na+ channels open, driving further depolarization (rising phase).

What two channel events occur at the peak of the action potential?

Voltage-gated Na+ channels close (inactivate), and voltage-gated K+ channels open.

What ion movement causes the falling phase (repolarization) of an action potential?

K+ exits the cell through open voltage-gated K+ channels.

What causes the undershoot (after-hyperpolarization) phase of the action potential?

Persistent exit of K+ that drives the membrane potential below the normal resting potential.

Which two mechanisms restore and maintain the membrane potential back to the -65 mV resting state?

Constantly open leaky K+ channels and active transporters like the Na+/K+ pump.

What is the typical resting membrane potential maintained in this neuron?

-65 mV