Transmission of Action Potentials

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  • Created by: Ellegrace
  • Created on: 29-12-15 17:55

Transmission of Action Potential

Local Currents

  • The opening of sodium ion channels at one particular point of the neurone upsets the balance of sodium and pottasium ions created by the sodium/pottasium ion pumps. This creates local currents in the cytoplasm of the neurone. These local currents cause sodium ion channels further along the membrane to open.
  • When an action potential occurs the sodium ion channels open at a particular point along the neurone.
  • This allows sodium ions to diffuse across the membrane from the region of higher concentration outside the neurone into the neurone.
  • the movement of sodium ions into the neurone upsets the balance of ionic concentrations created by the sodium/pottasium ion pumps.
  • The concentration of sodium ions inside the neurone rises at the point where the sodium ion channels are open.
  • This causes the sodium ions tp diffuse sideways, away from this region of increased concentration.
  • The movement of charged particles is a current called a local current.

Voltage-gated Sodium Ion Channels

  • Further along the membrane are more gated sodium ion channels.

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