Action Potential

What is the resting membrane potential of a neuron typically?

• 0 millivolts

• +70 millivolts

• -55 millivolts

• -70 millivolts

What causes the neuron to depolarize?

• Closing of potassium channels

• Stimulus from the nuerotransmitter

• Loss of potassium ions

• Loss of sodium ions

At what membrane potential does a neuron typically reach its threshold?

• 0 mV

• +55 mV

• -55 mV

• -70 mV

What is the threshold?

• At a certain charge, the Sodium-Potassum Channels open, allowing Sodium to flood in

• The point where the cell is too charged that it cuases damage

• At a certain charge, the Sodium-Potassum Channels open, allowing Potassium to flood in

• At a certain charge, the Sodium-Potassum Channels puases to rest.

What happens during the rising phase of the action potential?

• Neuron returns to resting membrane potential

• Sodium ions enter the cell, causing depolarization

• Sodium channels close

• Potassium ions flow out of the cell

What cuases the cell membranes to repolarize? [Efflux= movement out of the cell]

• Efflux of potassium ions through voltage-gated potassium channels
• Efflux of calcium ions through voltage-gated calcium channels
• Efflux of chloride ions through voltage-gated chloride channels
• Influx of sodium ions through voltage-gated potassium channels

What is the refractory period?

• The peak of the action potential

• The initial depolarization phase

• When neurotransmitters are released

• When the neuron is hyperpolarized and difficult to activate