10 Minute Neuroscience - Action Potentials

What are action potentials in the context of neuroscience?

• A type of neurotransmitter

• Electrical impulses that travel down neurons

• Chemical signals released by glial cells

• Physical movements of the neuron itself

Which statement accurately describes the distribution of sodium (Na+) and potassium (K+) ions in a neuron at rest?

• Both Na+ and K+ are more concentrated inside the neuron.

• Both Na+ and K+ are more concentrated outside the neuron.

• Na+ is more concentrated outside, and K+ is more concentrated inside the neuron.

• Na+ is more concentrated inside, and K+ is more concentrated outside the neuron.

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

• To allow both sodium and potassium ions to freely cross the membrane.

• To pump 3 potassium ions out and 2 sodium ions in.

• To pump 3 sodium ions out and 2 potassium ions in.

• To generate action potentials directly.

What is the typical resting membrane potential of a neuron?

• +40 millivolts (mV)

• -55 millivolts (mV)

• -70 millivolts (mV)

• 0 millivolts (mV)

What event must occur for an action potential to fire in a neuron?

• The neuron's membrane potential must become more negative than the resting potential.

• The resultant depolarization must reach a specific threshold.

• The neuron must be hyperpolarized.

• Potassium ion channels must open.

What is the primary event that causes the rapid depolarization phase of an action potential?

• Influx of potassium ions into the cell.

• Efflux of sodium ions out of the cell.

• Influx of positively charged sodium ions into the cell.

• Closure of voltage-gated potassium channels.

What causes the repolarization of a neuron's membrane potential after it reaches its peak during an action potential?

• Influx of sodium ions.

• Closure of voltage-gated potassium channels.

• Efflux of potassium ions out of the cell.

• Activation of the sodium-potassium pump.

What is the term for the process where an action potential appears to "jump" down a myelinated axon, regenerating at specific gaps?

• Continuous conduction.

• Synaptic transmission.

• Saltatory conduction.

• Passive diffusion.