FEATURES AND FUNCTIONS

• FEATURES OF A SYNAPSE?

  • unidirectionality
  • spatial summation
  • temporal summation
• UNIDIRECTIONALITY?

  information can only be passed in one direction (from presynaptic neurone to postsynaptic neurone)
• WHY IS A SYNAPSE UNIDIRECTIONAL?

  • only have vesicles of neurotransmitter on presynaptic neurone
  • only have neurotransmitter receptors on postsynaptic neurone
• SPATIAL SUMMATION?

  several different presynaptic neurones release enough neurotransmitter to exceed the threshold value
• TEMPORAL SUMMATION?

  single neurone releases neurotransmitter many times over a very short period to exceed threshold
• WHAT ARE THE FUNCTIONS OF SYNAPSES?

  • allow single impulses to create a number of simultaneous responses
  • allow nerve impulses from receptors reacting to different stimuli can contribute to a single response