Impulse

• An action potential is a brief and localised change in charges (voltage) across the membrane of the neuron.
• During an action potential, the inside of a neuron is relatively more positive than the outside.
• A stimulus causes the sodium ion channels to open.
• If the stimulus is strong enough, enough sodium comes in and creates the action potential.
• Saltatory conduction is when the action potential jumps between the nodes, these are the gaps in the myelin.
• Hyperpolarisation is when so many potassium ions move out that the difference in charge is even greater than it was before.
• Nerve impulses are the propagation of action potentials down the axon of a neuron.
• During resting potential, there is no net movement of ions across the membrane.
• During an action potential, there is net movement of ions across the membrane.
• The refractory period is when the sodium potassium pump returns the ions to their original position.
• label the follwoing

  A) -70

  B) -80

  C) +40

  D) -55

  
• depolarisation is the process where the stimulus is strong enough to reach threshold causing enough sodium to come in
• repolarisation is the process where potassium moves out