The Action Potential

(Media Resources)

MEDIA COLLECTION

Background Info

In neurons, action potentials are sudden and brief disruptions of the resting membrane potential along small portions of the axon.

Action Potential Recording
(Animation and Illustration)

Action potential: animated recording

Animation and Illustration (Labeled and Unlabeled)
(1125px X 1700px)

Axon Membrane Proteins
(Illustration)

Axon membrane showing embedded protein channels and pumps

Illustration (Labeled and Unlabeled)
(1125px X 1450px)

Voltage-gated Channel States
(Illustrations)

Axon membrane showing embedded protein channels and pumps

Illustration (Labeled and Unlabeled)
(1125px X 1450px)

Action Potential: Initiation Phase
(Animation and Illustrations)

Action potential - initiation phase

Voltage-gated sodium (Na+) channel - open state — Voltage-gated Na⁺ channels start converting to an open state (activation gates begin to open; inactivation gates remain closed).

Voltage-gated potassium (K+) channel - closed state — Voltage-gated K⁺ channels remain mostly in a closed state (gates closed).

Animation and Illustrations (Labeled and Unlabeled)
(1125px X 1700px / 1125px X 450px)

Action Potential: Depolarization Phase
(Animation and Illustrations)

Action potential - deploarization phase

Voltage-gated sodium (Na+) channel - open state — Voltage-gated Na⁺ channels continue to convert to an open state.

Voltage-gated potassium (K+) channel - open state — Voltage-gated K⁺ channels increasing converted to an open state (gates open).

Animation and Illustrations (Labeled and Unlabeled)
(1125px X 1700px / 1125px X 450px)

Action Potential: Depolarization Peak Phase
(Animation and Illustrations)

Action potential: peak of depolarization phase

Voltage-gated sodium (Na+) channel - inactivated state — Voltage-gated Na⁺ channels convert to an inactivated state (inactivation gates close).

Voltage-gated potassium (K+) channel - open state — Voltage-gated K⁺ channels are mostly in an open state (gates open).

Animation and Illustrations (Labeled and Unlabeled)
(1125px X 1700px / 1125px X 450px)

Action Potential: Repolarization Phase
(Animation and Illustrations)

Action potential: repolarization phase

Voltage-gated sodium (Na+) channel - inactivated state — Voltage-gated Na⁺ channels remain in an inactivated state (inactivation gates closed).

Voltage-gated potassium (K+) channel - open state — Voltage-gated K⁺ channels mostly remain in an open state (gates opened).

Animation and Illustrations (Labeled and Unlabeled)
(1125px X 1700px / 1125px X 450px)

Action Potential: Hyperpolarization Phase
(Animation and Illustrations)

Action potential: hyperpolarization phase

Voltage-gated sodium (Na+) channel - closed state — Voltage-gated Na⁺ channels start converting to a closed state (activation gates close; inactivation gates open).

Voltage-gated potassium (K+) channel - closed state — Voltage-gated K⁺ channels mostly enter a closed state (gates closed) after a delay.

Illustrations (Labeled and Unlabeled)
(1125px X 1700px / 1125px X 450px)

Action Potential: Restoration Phase
(Animation and Illustrations)

Action potential: return to resting potential

Voltage-gated sodium (Na+) channel - closed state — Voltage-gated Na⁺ channels mostly convert to a closed state (activation gates close; inactivation gates open).5

Voltage-gated potassium (K+) channel - closed state — Voltage-gated K⁺ channels mostly remain a closed state (gates closed) after a delay.

Illustrations (Labeled and Unlabeled)
(1125px X 1700px / 1125px X 450px)

Action Potential Refractory Periods
(Illustration)

Action potential - refractory periods

With and Without Axon (Labeled and Unlabeled)
(1125px X 1700px / 1125px X 900px)

All-or-None Principle
(Learning Activity)

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