Biopsychology

• Sensory Neuron 


  Found in the PNS

  Sends impulses from the receptor towards the CNS
• Relay Neuron 


  Found in the CNS

  Transmits impulses between the sensory and motor neurons
• Motor Neurons


  Found in the PNS

  Controls muscle movement
• Action Potentials


  How electrical impulses are passed along a neuron
• Signals within neurons are transmitted as action potentials


  Signals between neurons are transmitted chemically across a synapse via a neurotransmitter
• What are dendrites?

  Branch like structures that carry impulses towards the cell body
• What do axon do?

  Carries impulses away from the cell body
• What are the myelin sheaths?

  Fatty layer around the axon which speeds up electrical transmission
• What are Nodes of Ranvier?

  Gaps between the myelin sheath which speed up electrical transmission
• What do terminal buttons do?

  Communicate with the next neuron in the chain across the synapse
• Information can only travel in one direction at a synapse due to the synaptic vesicles containing the neurotransmitter are only present in the presynaptic membrane

  Also , diffusion of the neurotransmitters mean they can only go from high to low concentration - from pre synaptic to post synaptic

  Receptors for neurotransmitters are only present on the post synaptic membrane