synaptic transmission

• Action potential- electrical activity caused by depolarising event.
• Synaptic transmission

  1. In resting state the inside of the neurone is more negative

  than the outside, when a neurone is activated by a stimulus

  the inside becomes more positive -action potential. This

  generates a wave of depolarisation down the axon creating

  an electrical impulse
• 2) when the electrical impulse reaches the end of the neurone it triggers the release of neurotransmitters from vesicles
• 3) Once a neurotransmitter crosses a synaptic cleft it is taken up by the postsynaptic receptors
• 4) A chemical message is then converted back into an electrical impulse and sent along the neurone
• Each neurotransmitter has a specific molecular structure that fits perfectly to the receptor.

  Neurotransmitters have specific functions eg acetylcholine found at motor neurones meeting muscles (neuromuscular junction), when released they cause them to contract