Neurons and synaptic transmission

• Neuronal cells transmit information through nerve impulses
• 4 main components of a neuron cell.

  • Dendrites
  • Cell body
  • Axon
  • Axon terminals
• Electrical signals are actually changes in voltage.
• • Small waves of positively charged particles flow into the neuron at the dendrites.
  • This causes small positive changes in voltage inside the cell.
  • Nerve impulses are triggered in the cell body of a neuron.
  • A neuron only generates a nerve impulse if the change in voltage is large.
  • Once a nerve impulse is generated it travels down the axon.
  • The nerve impulse reaches the axon terminal.
• Process through which nerve impulses are transmitted across the synapse.

  Synaptic transmission
• The gap between the axon terminal and dendrites of 2 neurons.

  Synapse
• The part where the nerve impulse first arrives.

  Pre-synaptic terminal
• On the other side of the synapse.

  Post synaptic terminal
• The gap in the middle of a synapse

  A synaptic cleft
• Carries messages from CNS to muscles and glands.

  Motor neuron
• When the electrical signal reaches the end of a neuron, synaptic vesicles release neurotransmitters which relay the signal across the synapse.


  Neurotransmitter
• When neurotransmitters make it more likely that the next neuron will fire.

  Excitation
• When neurotransmitters make it less likely for the next neuron to fire.

  Inhibition
• Communicate with the next neuron in the chain.

  Terminal buttons
• Fatty layer that covers axon for protection and to speed up transmission.

  Myelin Sheath
• Speeds up transmission.

  Nodes of ranvier
• Contains genetic material of the cell.

  Nucleus
• a neurotransmitter, a chemical messenger in your brain.

  It slows down your brain by blocking specific signals in your central nervous system (your brain and spinal cord).

  GABA is known for producing a calming effect.


  Gamma-aminobutyric acid (GABA)