Understanding Action Potentials

What is the term used to describe the reversal of membrane potential during an action potential?

• Polarization

• Hyperpolarization

• Depolarization

• Repolarization

What is the approximate threshold potential required for an action potential to occur?

• 555 mV

• 555 ms

• 70 mV

• 30 mV

How does a supra-threshold stimulus affect an action potential?

• Decreases its frequency

• Increases its frequency

• Decreases its amplitude

• Increases its amplitude

What is the resting membrane potential of a neuron?

• 555 mV

• -70 mV

• 0 mV

• 30 mV

Which ion channel opens during depolarization to allow sodium into the cell?

• Potassium channel

• Chloride channel

• Calcium channel

• Sodium channel

What happens to the sodium channel's inactivation gate during repolarization?

• It becomes more permeable

• It remains unchanged

• It closes

• It opens

In which type of conduction does the action potential jump from node to node?

• Direct conduction

• Continuous conduction

• Indirect conduction

• Saltatory conduction

What is the effect of a larger axon diameter on the speed of impulse propagation?

• Slows down the impulse

• Speeds up the impulse

• No effect

• Reverses the impulse

How does increased myelination affect the speed of an action potential?

• Stops it

• No effect

• Speeds it up

• Slows it down

What is the relationship between temperature and the speed of impulse propagation?

• Temperature has no effect

• Lower temperature speeds it up

• Higher temperature slows it down

• Higher temperature speeds it up