Neurons and Synaptic Transmission

• What are Neurons?


  - Specialised cells that carry neural information

  
• What is the role of the Sensory Neuron?


  - Carries nerve impulse from sensory receptor (e.g. vision, taste, smell) to CNS
• What is the role of the Relay Neuron?


  - Lies between sensory input and motor output

  - Allow sensory and motor neurons to communicate
• What is the role of the Motor Neuron?


  - Located in CNS, project axons outside to control muscles

  - Form synapses w/muscles and control contractions

  - Releases neurotransmitters which bind to receptors and trigger response
• What is Synaptic Transmission?


  - Process by which nerve impulse passes across synaptic gap from presynaptic neuron to postsynaptic neuron

  - Impulse reaches end of axon which has synaptic vesicles containing neurotransmitters that allow transfer of impulse
• What are Excitatory Neurotransmitters?


  - Nervous systems 'on' switches, increase likelihood of neuron 'firing'

  - When one binds with a postsynaptic receptor an electrical change occurs in cell membrane, results in excitatory post-synaptic potential (EPSP) → meaning post-synaptic cell more likely to fire
• What are Inhibitory Neurotransmitters?


  - Nervous systems 'off' switches, decrease likelihood of neuron firing

  - Responsible for calming mind and body, induce sleep and filter unnecessary excitatory neurotransmitters