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Neuroscience

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Voltage-gated $Na^+$ versus $K^+$ Channels

NEURO-4C0BE0

Voltage-gated sodium channels and voltage-gated potassium channels have many differences in their gating properties. It is important to understand these differences because they explain why different phases of the action potential behave in the way they do.

Read the following statements carefully, and choose ALL that correctly describe the differences between voltage-gated sodium channels and voltage-gated potassium channels.

A

${ Na }^{ + }$ channels open immediately once the membrane potential is depolarized; ${ K }^{ + }$ channels open with a 1-msec delay.

B

${ Na }^{ + }$ channels open sooner and also close sooner than ${ K }^{ + }$ channels.

C

${ K }^{ + }$ channels open sooner and stay open longer than ${ Na }^{ + }$ channels.

D

${ Na }^{ + }$ channels open when the membrane is depolarized, and ${ K }^{ + }$ channels open when the membrane is hyperpolarized.