action potential quiz

What area(s) of the neuron generate signals that open the voltage-gated channels in the first part of the axon, thus causing an action potential?

Dendrites and cell body

The fastest conduction of an action potential would occur in an axon with which of the following characteristics?

Large diameter and myelinated

What is the name of the disease in which the myelin sheaths of central nervous system axons are destroyed?

Multiple sclerosis

The action potential is a transient change in the resting membrane potential from -70 mV to +30 mV, then back to -70 mV. This change is caused by the opening of first _____ then _____ voltage-gated channels.

Na+ then K+

If depolarization reaches -55 mV, an action potential will be generated. What is this -55 mV trigger point called?

Threshold

At the end of the depolarization phase, what voltage-gated channels open to help restore the resting membrane potential?

Voltage-gated K+ channels

After an action potential, the membrane becomes more negative than -70 mV. This period is called:

hyperpolarization.

As the axon hillock depolarizes, Voltage-gated Na+ channels open and Na+ moves (into or out of) __________ the cell causing further (depolarization or repolarization) __________.

into; depolarization

Repolarization is caused by the movement of what ion (sodium or potassium), in what direction (into or out of the cell)?

potassium; out of the cell

After a neuron has generated an action potential, it cannot generate another one for a while. This period is called:

the absolute refractory period.