Synoptic transmission

• Synaptic transmission

  A) Axon

  B) Synapse

  C) Dendrite

  D) neurotransmitter

  E) synaptic vesicle

  F) presynaptic nerve terminal

  G) postsynaptic receptor sites

  
• Neurons communicate with each other in neural groups
• What is the gap called separating neurons?

  Synapse
• Signals between neurons are transmitted chemically across the synapse
• What happens when the electric impulse reaches the presynaptic terminal?

  Triggers release of neurotransmitter from synaptic vesicles
• What are neurotransmitters?

  Chemicals that diffuse across the synapse to the next neuron
• What happens once a neurotransmitter crosses the synapse?

  Taken up by a postsynaptic receptor site
• What happens to the chemical message once it reaches the postsynaptic receptor site?

  Converted back into an electrical impulse
• The direction of travel of a neurotransmitter can only be one way
• Why can the direction of travel of a neurotransmitter only be one way?

  As they are released from the presynaptic neuron terminal and received by the postsynaptic neuron
• Each neurotransmitter has its own structure that fits perfectly into a postsynaptic receptor site
• What is excitation?

  When a neurotransmitter increases the positive charge of the postsynaptic neuron - increasing the likelihood the postsynaptic neuron will pass on the electrical impulse
• What is inhibition?

  When a neurotransmitter increases the negative charge of the postsynaptic neuron - decreasing the likelihood the postsynaptic neuron will pass on the electrical impulse
• What is whether a postsynaptic neuron fires decided by?

  Summation
• What is summation?

  Where the sum of the excitatory and inhibitory signals reaches the threshold and the action potential of the postsynaptic neuron is triggered