Impulse Transmission

• Impulse is flow of current along a neurone; similar to flow of current in a wire except current is carried along a neurone by flow of positive ions and not electrons
• ‘All or Nothing’ Response

  • Action potential peaks id +40MV, stimulus larger than threshold does not cause a larger action potential value; either triggers a full action potential or nothing
  • However, impulses/action potentials frequency along axons can vary; larger stimulus will increase frequency
• At high temperature, kinetic energy is increased so ion diffuse faster; speeds up depolarisation and refractory periods (only true up to 40C above protein ion channels denature and disrupts membrane fluidity, decreasing speed)