neurons + synaptic transmission

• sensory neurone: PNS to CNS, PNS in ganglia, long dendrites, short axons

  relay neurone (97% of neurones): sensory to motor, in brain + visual system, short dentures, short axons

  motor neurone: CNS to effector, short dendrites, long axons
• electrical transmission - firing neurone

  resting state: inside cell negatively charger (outside positive)

  neurone activated: inside positively charged for split second - makes electrical impulse that travels down axon
• 1. Sensory neurone
  2. relay neurone
  3. motor neurone
  4. dendrites: carry nerve impulse from neurone neighbour too cell body
  5. mylein sheath: protects axon + speeds up electrical transmission or impulse
  6. nodes of ranvier: segments shear to ensure speed - makes it jump
  7. terminal buttons: communicate with next neurone in chain across synapse
  8. axon: carry nerve impulse away from cell body
  9. cell body: nucleus - genetically material inside

  
• Synaptic tranmission

  chemical transition process

  1. Electrical impulse reaches end of neurone
  2. neurotrandmitter released form synaptic vesciles
  3. enters synapse, neurotransmitter crosses gap
  4. taken up by postsynaptic receptor site on receiving end of dendrite
  5. chemical -> electrical impulse
  6. process of transition in other neurone
• neurotransmistter

  chemical that diffuses across synaptic to next neurone - specialist function (molecular structure fits into postsynaptic receptor site perfectly)

  excitatory (neurone positively charged + more likely to fire) or inhibitory (negatively charged + less likely to fire) effect on neighbouring neurone

  summation: total of impulses, net effect excitatory or inhibitory - decided if postsynaptic neurone fires