Action Potential of a Neuron

When does repolarization begin?

• -40 mV
• 40 mV
• -70 mV
• -55 mV

What triggers the threshold potential?

• A stimulus
• Sodium ions
• An axon
• An electrical impulse

Repolarization happens after depolarization.

• True
• False

What is the resting potential of a neuron?

• 80 mV
• -35 mV
• -70 mV
• 35 mV

Which ions are related to the action potential?

• Na⁺
• Calcium
• Sodium
• Na⁺, K⁺

What is the refractory period?

• When all the channels are open
• When the Na⁺ channel is open
• When none of the channels are open
• When both the Na⁺ and K⁺ channels are open

Hyperpolarization is another term to describe the refractory period.

• True
• False

Which ion gates open first?

• Sodium
• Potassium

Why do the sodium channels close during repolarization?

• Because why not
• To prevent firing another action potential
• So the potassium channels can open
• None of the above

Which label is NOT correct?

• A. Depolarization

• B. Depolarization

• E. Refractory Period

• D. Repolarization