Propagation of Action Potential Quiz

How do action potentials propagate in unmyelinated axons?

• By diffusion of chloride ions

• By interaction between passively spreading membrane depolarization and voltage-gated sodium channels

• By active transport of sodium ions

• By diffusion of potassium ions

Tags

NGSS.HS-PS2-5

What happens when one segment of cell membrane is depolarized enough to open its voltage-gated sodium channels?

• Calcium enters the cell by facilitated diffusion

• Sodium enters the cell by facilitated diffusion

• Potassium enters the cell by active transport

• Chloride enters the cell by diffusion

How does a wave of positivity move down the axon?

• Calcium ions nudge adjacent ions down the axon by electrostatic repulsion

• Potassium ions attract negative ions away from the adjacent membrane

• Negatively charged chloride ions attract adjacent ions down the axon

• Positively charged sodium ions nudge adjacent ions down the axon by electrostatic repulsion

What happens once the adjacent segment of membrane is depolarized?

• The voltage-gated potassium channels in that segment open

• The voltage-gated chloride channels in that segment open

• The voltage-gated sodium channels in that segment open

• The voltage-gated calcium channels in that segment open

What is the result of the process repeating down the length of the axon?

• An action potential lost at each segment of membrane

• An action potential regenerated at each segment of membrane

• A decrease in membrane potential

• An increase in membrane depolarization

How do voltage-gated sodium channels contribute to the propagation of action potential?

• They open when the cell membrane is depolarized

• They open when the cell membrane is at resting potential

• They open when the cell membrane is hyperpolarized

• They open when the cell membrane is at peak potential

What is the role of positively charged sodium ions in action potential propagation?

• They nudge adjacent ions down the axon by electrostatic repulsion

• They attract negative ions towards the adjacent membrane

• They facilitate the diffusion of potassium ions

• They inhibit the movement of chloride ions

How does the process of action potential propagation start in an axon?

• With the diffusion of calcium ions

• With the active transport of potassium ions

• With the diffusion of chloride ions

• With the interaction between passively spreading membrane depolarization and voltage-gated sodium channels

What happens when the voltage-gated sodium channels in a segment of membrane open?

• Sodium enters the cell by facilitated diffusion

• Potassium enters the cell by active transport

• Calcium enters the cell by facilitated diffusion

• Chloride enters the cell by diffusion

What is the main mechanism by which action potentials are regenerated down the length of the axon?

• Voltage-gated sodium channels opening in each segment of membrane

• Voltage-gated potassium channels opening in each segment of membrane

• Voltage-gated chloride channels opening in each segment of membrane

• Voltage-gated calcium channels opening in each segment of membrane