Figure 12.21. Membrane potential and ion channels during an action potential.

Figure 12.21Membrane potential and ion channels during an action potential

(A) Changes in membrane potential at one point on a squid giant axon following a stimulus. ENa and EK are the equilibrium potentials for Na+ and K+, respectively. (B) The membrane potential first increases as voltage-gated Na+ channels open. The membrane potential then falls below its resting value as the Na+ channels are inactivated and voltage-gated K+ channels open. The voltage-gated K+ channels are then inactivated, and the membrane potential returns to its resting value.

From: Transport of Small Molecules

Cover of The Cell
The Cell: A Molecular Approach. 2nd edition.
Cooper GM.
Sunderland (MA): Sinauer Associates; 2000.
Copyright © 2000, Geoffrey M Cooper.

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