Action Potentials

What is the term for the propagation of an action potential from one gap in the myelin to the next?

• Saltatory conduction

• Voltage-gated conduction

• Graded conduction

• Mechanically-gated conduction

What is the main force behind every action, thought, and feeling in the body?

• Voltage

• Current

• Resistance

• Action potentials

What is the purpose of the refractory period in a neuron?

• To prevent signals from traveling in both directions down the axon

• To maintain the resting membrane potential

• To trigger the sodium-potassium pump

• To open ligand-gated channels

What is the purpose of myelin sheath on an axon?

• To increase the frequency of action potentials

• To decrease the conduction velocity of action potentials

• To prevent action potentials from occurring

• To increase the conduction velocity of action potentials

What kind of signal is an action potential?

• chemical

• electrical

Threshold to initiate an action potential

• -70mV

• -55mV

• +30mV

• <70mV

Which channels are open at time #1?

• leak channels only

• gated Na channels

• gated K channels

• none

Which channels open FIRST at time #2?

• leak channels only

• gated Na channels

• gated K channels

• none

Which channels open SECOND at time #2?

• leak channels only

• gated Na channels

• gated K channels

• none

Which term best describes time #4

• polarized

• depolarization

• repolarization

• hyperpolarization