Neurone

• Types

  • Sensory:
  • Carry messages from sensory receptors (e.g. touch receptors) PNS to CNS
  • Long dendrites and short axons
  • Motor:
  • Carry messages from CNS, along PNS to effectors (e.g. muscles)
  • Short dendrites and long axons
  • Relay (or inter-neurons)
  • Connect sensory and motor neurons
  • Short dendrites and axons
  • Only in CNS
• Synaptic Transmission

  • Chemical messages to adjacent neurons through synaptic gap/cleft (synapse)
  • Pre-synaptic sends, postsynaptic receives
  • Neurons release neurotransmitters; no single neuron releases all
  • Vesicles travel to terminal button's out membrane, fuse casing; neurotransmitters flood gap
  • Receptor sites (receptors) are specific, once detected, they absorb
  • Those not absorbed; destroyed by enzymes or reabsorbed pre-synaptic (reuptake)
  • Message received on dendrite, travels to soma
  • Neurons become charged after multiple transmissions
  • Generate small electric impulse at axon hillock