Ch. 15 Neurons & Action Potentials

Front

What is the function of the sodium-potassium pump?

Back

The sodium-potassium pump exchanges K+ and Na+ to reestablish the resting potential.

Front

What happens during depolarization in a neuron?

Back

During depolarization, sodium channels open, allowing Na+ to flow into the neuron.

Front

What is the Node of Ranvier?

Back

The Node of Ranvier is a junction along a myelinated axon where Na+ and K+ flow in and out of the neuron.

Front

What stage of action potential has both Na+ and K+ present in large concentrations inside the neuron?

Back

Depolarization.

Front

What does the resting potential of a neuron refer to?

Back

The resting potential is the state of a neuron when it is not actively sending a signal, typically around -70mV.

Front

What is depolarization?

Back

Depolarization is the process by which the membrane potential becomes less negative (more positive) due to the influx of Na+.

Front

What is repolarization?

Back

Repolarization is the process of returning the membrane potential to a more negative value after depolarization, primarily through the efflux of K+.

Front

What is hyperpolarization?

Back

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

Front

What role do calcium channels play in neurons?

Back

Calcium channels open during depolarization, allowing Ca2+ to enter the neuron, which is crucial for neurotransmitter release.

Front

What is the significance of myelin sheath in neurons?

Back

The myelin sheath insulates axons, increasing the speed of action potentials through saltatory conduction.