15. The Action Potential

  1. Stephen R. Bolsover1,
  2. Jeremy S. Hyams2,
  3. Elizabeth A. Shephard3,
  4. Hugh A. White3 and
  5. Claudia G. Wiedemann1

Published Online: 27 JAN 2004

DOI: 10.1002/047146158X.ch15

Cell Biology: A Short Course, Second Edition

Cell Biology: A Short Course, Second Edition

How to Cite

Bolsover, S. R., Hyams, J. S., Shephard, E. A., White, H. A. and Wiedemann, C. G. (2003) The Action Potential, in Cell Biology: A Short Course, Second Edition, John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/047146158X.ch15

Author Information

  1. 1

    Department of Physiology, University College, London, UK

  2. 2

    Department of Biology, University College, London, UK

  3. 3

    Department of Biochemistry and Molecular Biology, University College, London, UK

Publication History

  1. Published Online: 27 JAN 2004
  2. Published Print: 14 NOV 2003

ISBN Information

Print ISBN: 9780471263937

Online ISBN: 9780471461586

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Keywords:

  • action potential;
  • voltage-gated calcium channel;
  • voltage-gated sodium channel;
  • axon;
  • saltatory conduction;
  • myelin

Summary

The action potential is an explosive depolarization of the plasma membrane. It can be driven by the influx of calcium ions through voltage-gated calcium channels, as in the sea urchin egg, or sodium ions through voltage-gated sodium channels, as in human nerve cells. Action potentials travel rapidly along the long nerve cell processes called axons, especially if the axon is insulated by myelin. The amplitude of a signal is coded by the frequency of action potentials, all of which have the same amplitude.