neurons and synaptic transmission

• types of neurons:

  • sensory neurons: carry messages from PNS to CNS - long dendrites and short axons
  • relay neurons: connect sensory neurons to motor and other relay neurons - short dendrites and short axons
  • motor neurons: connect the CNS to effectors (muscle glands) - short dendrites and long axons
• • cell body: includes a nucleus, containing genetic material. The dendrites protrude from the cell body, carrying nerve impulses
  • axon: carries impulses away from cell body, covered in a fatty layer of myelin sheath that protests the axon and speeds up electrical transmission of the impulse
  • the myelin sheath is separated by 'nodes of Ranvier' that speed up the transmission of the impulse by forcing it to 'jump' across gaps
  • terminal buttons: communicate with the next neuron (synapse)
• synaptic transmission

  1. synaptic vesicles: hold the mitochondria
  2. signals within neurons are transmitted chemically across the synapse
  3. the presynaptic terminal triggered the release of the neurotransmitter
  4. floats across the gap and the receptors catch the impulse