Membrane Potentials and Action Potentials in Neurologic Transmission

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What is the typical resting membrane potential in neurons?

-30 millivolts (mV)

-90 millivolts (mV)

-70 millivolts (mV) (correct)

-50 millivolts (mV)

What causes the change from negative to positive membrane potential during the depolarization phase of action potentials?

Efflux of calcium ions

Influx of chloride ions

Rapid influx of sodium ions (correct)

Outward movement of potassium ions

What restores the negative membrane potential during the repolarization phase of action potentials?

Efflux of calcium ions

Influx of chloride ions

Outward movement of potassium ions (correct)

Influx of sodium ions

What is the role of resting membrane potential in neurologic transmission?

Essential for maintaining the excitability of neurons Signup and view all the answers

What allows passive movement of K+ out of the cell, contributing to the resting membrane potential?

Potassium leak channels Signup and view all the answers

What briefly becomes more negative than the resting state before returning to the resting potential during action potentials?

Membrane potential during hyperpolarization Signup and view all the answers

What actively transports ions, contributing to the establishment of resting membrane potential?

Sodium-potassium pump Signup and view all the answers

What permits a small influx of Na+ and contributes to the establishment of resting membrane potential?

Sodium leak channels Signup and view all the answers

What serves as the basis for communication between neurons and with target cells?

Action Potentials Signup and view all the answers

Where are action potentials initiated?

Axon hillock Signup and view all the answers

What principle states that action potentials either occur fully or do not occur at all?

All-or-None Principle Signup and view all the answers

What influences the frequency of action potentials?

Strength and duration of the stimulus Signup and view all the answers

What insulates axons, increasing the speed of action potential conduction?

Myelin sheaths Signup and view all the answers

What facilitates saltatory conduction along myelinated axons?

Nodes of Ranvier Signup and view all the answers

What generally increases the speed of action potential conduction?

Higher temperatures Signup and view all the answers

What can influence the ease of action potential initiation by affecting the proximity of the resting membrane potential to the threshold?

Resting Membrane Potential Signup and view all the answers

What can influence action potential conduction by altering extracellular and intracellular ion concentrations?

Ion Concentrations Signup and view all the answers