Understanding Action Potentials

What is the resting membrane potential of a neuron?

• Negative 93 millivolts

• Positive 70 millivolts

• Zero millivolts

• Negative 70 millivolts

Which part of the neuron is primarily involved in the initiation of an action potential?

• Cell body

• Axon hillock

• Dendrites

• Axon terminals

What happens when the voltage-gated sodium channels open during depolarization?

• Sodium ions leave the cell

• Potassium ions enter the cell

• Sodium ions enter the cell

• Potassium ions leave the cell

What is the equilibrium potential for sodium during depolarization?

• Negative 70 millivolts

• Zero millivolts

• Positive 58 millivolts

• Negative 93 millivolts

During repolarization, which ions move out of the neuron?

• Calcium ions

• Potassium ions

• Chloride ions

• Sodium ions

What is the term for when the membrane potential becomes more negative than the resting potential?

• Hyperpolarization

• Repolarization

• Equilibrium

• Depolarization

What prevents the membrane potential from reaching the equilibrium potential of potassium?

• Sodium channels closing

• Potassium channels closing

• Chloride channels opening

• Calcium channels opening

Which mechanism helps restore the resting membrane potential after an action potential?

• Voltage-gated sodium channels

• Sodium-potassium pump

• Calcium pump

• Chloride channels

What is the role of passive ion channels in neurons?

• To maintain the resting membrane potential

• To hyperpolarize the neuron

• To initiate action potentials

• To depolarize the neuron

What is the main function of the sodium-potassium pump in neurons?

• To depolarize the neuron

• To initiate action potentials

• To repolarize the neuron

• To maintain the resting membrane potential