Action Potential Quiz

What is the nature of an action potential?

• It is a graded event.

• It is an all-or-nothing event.

• It is a reversible event.

• It is a slow event.

What primarily causes the inside of a neuron to be negatively charged at resting membrane potential?

• Presence of positively charged ions inside

• Presence of negatively charged ions outside

• Presence of negatively charged ions inside

• Absence of ions inside

What must a neuron receive to initiate an action potential?

• A weak stimulus

• A threshold stimulus

• A random stimulus

• A continuous stimulus

What happens when the threshold stimulus is reached in a neuron?

• Sodium channels close

• Potassium channels open

• Voltage-gated sodium channels open

• Calcium channels open

What phase is characterized by the rapid influx of sodium ions into the neuron?

• Repolarization

• Depolarization

• Refractory period

• Propagation

What occurs during the repolarization phase of an action potential?

• Sodium ions flow into the cell

• Potassium ions flow out of the cell

• Calcium ions flow into the cell

• Chloride ions flow out of the cell

What is the refractory period?

• The period when the neuron can generate another action potential immediately

• The period when the neuron cannot generate another action potential

• The period when the neuron is at rest

• The period when the neuron is hyperactive

How does the action potential travel along the axon?

• As a wave of repolarization

• As a wave of depolarization

• As a wave of hyperpolarization

• As a wave of resting potential

What happens when the action potential reaches the axon terminals?

• It stops

• It triggers the release of neurotransmitters

• It reverses direction

• It causes the neuron to shrink

What is the role of neurotransmitters released at the axon terminals?

• They bind to receptors on the receiving neuron

• They degrade the action potential

• They cause the neuron to depolarize

• They inhibit the action potential