Action Potentials

Front

What is an action potential?

Back

An action potential is a rapid, temporary change in the membrane potential of a neuron, allowing it to transmit signals along the axon.

Front

What is the resting membrane potential of a neuron?

Back

The resting membrane potential is typically around -70 mV, indicating the inside of the neuron is more negative compared to the outside.

Front

What occurs during depolarization?

Back

During depolarization, sodium channels open, allowing sodium ions to flow into the neuron, making the inside more positive.

Front

What is the threshold potential for initiating an action potential?

Back

The threshold potential is typically around -55 mV, the level that must be reached for an action potential to occur.

Front

What happens at +30 mV during an action potential?

Back

At +30 mV, sodium channels close, potassium channels open, and repolarization begins.

Front

What is repolarization?

Back

Repolarization is the process of returning the membrane potential back to a negative value after depolarization, primarily through the opening of potassium channels.

Front

What role do voltage-gated potassium channels play?

Back

Voltage-gated potassium channels open during repolarization, allowing potassium ions to exit the neuron and restore the negative membrane potential.

Front

What is the significance of the axon in action potentials?

Back

The axon is the part of the neuron that conducts action potentials away from the cell body to the axon terminals.

Front

What is the function of sodium-potassium pumps?

Back

Sodium-potassium pumps help maintain the resting membrane potential by actively transporting sodium out of and potassium into the neuron.

Front

What is hyperpolarization?

Back

Hyperpolarization is when the membrane potential becomes more negative than the resting potential, often due to excessive potassium ion efflux.