Action Potential

Front

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

Back

The sodium-potassium pump restores the resting potential of the neuron by actively transporting sodium ions out of the cell and potassium ions into the cell.

Front

What is the threshold potential required to trigger an action potential in a neuron?

Back

-55 mV is the threshold required to activate an action potential.

Front

What structure is represented by the letter 'B' in a neuron diagram?

Back

Dendrite.

Front

What is the role of the myelin sheath in neuronal function?

Back

The myelin sheath insulates the axon of a neuron, enabling electrical signals to travel down the axon at higher speeds.

Front

During which phase of the action potential is the potassium channel open?

Back

The potassium channel is open during repolarization.

Front

What is the resting membrane potential of a typical neuron?

Back

The resting membrane potential of a typical neuron is approximately -70 mV.

Front

What occurs during depolarization of a neuron?

Back

During depolarization, the membrane potential becomes less negative (more positive) as sodium ions rush into the cell.

Front

What is the significance of the action potential's all-or-nothing principle?

Back

The all-or-nothing principle means that once the threshold is reached, an action potential will occur fully; it does not vary in strength.

Front

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

Back

Voltage-gated ion channels open in response to changes in membrane potential, allowing ions to flow in and out of the neuron, which is crucial for action potential generation.

Front

What happens to the membrane potential during the repolarization phase?

Back

During repolarization, the membrane potential returns to a more negative value as potassium ions exit the cell.