Action Potential Physiology (FULL VIDEO)

The video explains the action potential in neurons, focusing on the role of the axon, sodium-potassium pump, and ion channels. It describes how action potentials propagate along the axon, the function of sodium and potassium channels, and the phases of depolarization and repolarization. A graphical representation of these processes is also provided.

What part of the neuron is primarily responsible for the action potential?

• Soma

• Nucleus

• Axon

• Dendrites

What is the primary function of the sodium-potassium pump?

• To depolarize the cell

• To generate action potentials

• To release neurotransmitters

• To maintain ion concentration gradients

Which ions are primarily involved in the depolarization phase of an action potential?

• Calcium ions

• Chloride ions

• Sodium ions

• Potassium ions

What is the direction of action potential propagation along the axon?

• Bidirectional

• Unidirectional towards the axon terminal

• Random

• Unidirectional towards the soma

What triggers the opening of voltage-gated sodium channels during an action potential?

• Decrease in external sodium concentration

• Increase in internal potassium concentration

• Change in voltage across the membrane

• Presence of neurotransmitters

What is the role of voltage-gated potassium channels in action potentials?

• To repolarize the cell

• To release neurotransmitters

• To maintain resting potential

• To initiate depolarization

What is the term for the phase when the inside of the cell becomes more positive?

• Hyperpolarization

• Resting potential

• Repolarization

• Depolarization

What happens during the repolarization phase of an action potential?

• Sodium ions enter the cell

• Potassium ions exit the cell

• Calcium ions enter the cell

• Chloride ions exit the cell

What is the significance of the sodium-potassium pump after an action potential?

• It releases neurotransmitters

• It restores ion gradients

• It repolarizes the cell

• It depolarizes the cell

What is hyperpolarization in the context of action potentials?

• A phase where the cell releases neurotransmitters

• A phase where the cell becomes more positive than at rest

• A phase where the cell returns to resting potential

• A phase where the cell becomes more negative than at rest