Nerve Signaling Quiz

What is the definition of membrane potential?

• The difference in electrical charge across a membrane

• The movement of ions across a membrane

• The resting state of a neuron

• The transmission of an action potential

What is the typical value of resting membrane potential?

• -50 mV

• -70 mV

• -90 mV

• -110 mV

What is the function of the sodium-potassium pump?

• Maintains an imbalance in the distribution of positive ions

• Allows rapid diffusion of sodium ions into the cell

• Increases the membrane potential

• Triggers the opening of potassium channels

What is the term for a slight shift away from the resting membrane potential in a specific region of the plasma membrane?

• Action potential

• Resting potential

• Local potential

• Synaptic potential

What occurs during excitation in a local potential?

• Opening of additional sodium channels

• Opening of additional potassium channels

• Rapid diffusion of sodium ions into the cell

• Rapid diffusion of potassium ions out of the cell

What is the mechanism that produces an action potential?

• Opening of stimulus-gated potassium channels

• Rapid diffusion of potassium ions into the cell

• Opening of voltage-gated sodium channels

• Rapid diffusion of sodium ions out of the cell

What happens during repolarization of an action potential?

• Opening of potassium channels and outward diffusion of potassium ions

• Opening of sodium channels and inward diffusion of sodium ions

• Opening of calcium channels and influx of calcium ions

• Opening of chloride channels and influx of chloride ions

What is the absolute refractory period?

• A brief period during which a neuron's membrane resists restimulation

• The time during which the membrane is repolarizing

• The time during which the membrane is hyperpolarized

• The time during which the membrane is at resting potential

What is the term for the reversal in polarity that causes electrical current to flow between the site of the action potential and adjacent regions of membrane?

• Saltatory conduction

• Refractory period

• Synaptic transmission

• Propagation of the action potential

What occurs at chemical synapses?

• Action potentials simply continue along the postsynaptic plasma membrane

• Presynaptic cells release chemical transmitters across a tiny gap to the postsynaptic cell

• Presynaptic cells release electrical signals to the postsynaptic cell

• Postsynaptic cells release chemical transmitters to the presynaptic cell