Types of Neurons

• What are neurons and their role?


  nerve cells that have been adapted to carry electrical impulses and info around the body
• Structure of a neuron

  
• What is the function of sensory neurons?

  carry impulses from sensory receptors to the CNS

  
• Where are sensory neurons located?


  eyes, ears, tongue, skin
• What is the purpose of relay neurons?

  allow sensory and motor neurons to communicate
• Where are relay neurons found?

  brain and spinal cord
• What is the function of motor neurons?

  • connect CNS to effectors
  • release neurotransmitters that trigger muscle responses
• where are motor neurons located?

  CNS
• Order of neurons

  1. stimulus

  2. receptor

  3. sensory neuron

  4. relay neuron

  5. motor neuron

  6. effector

  7. response
• presynaptic neuron


  neuron that transmits neural impulse
• postsynaptic neuron


  neuron that receives neural impulse
• axon


  nerve fibre that conducts electrical impulses away from the cell body towards the end of a neuron
• presynaptic nerve terminal


  end of the presynaptic neuron and facilitates communication with the next neuron
• synaptic vesicle


  stores neurotransmitters
• neurotransmitter


  chemical substances made by the neuron specifically to transmit a message
• synapse

  gap between presynaptic neuron and postsynaptic neuron
• postsynaptic receptor sites


  found on the surface of a postsynaptic neuron and binds to neurotransmitters
• process of synaptic transmission


  1. impulse travels along the axon
  2. neurotransmitters are released towards presynaptic neuron terminal
  3. releases neurotransmitters across synapse
  4. neurotransmitter binds to receptors
  5. neurotransmitters are reabsorbed
• excitatory neurotransmitters


  makes neuron more likely to fire
• inhibitory neurotransmitters


  makes neuron less likely to fire
• summation


  postsynaptic nerve cell can receive EPSPs and IPSPs at the same time, must reach a certain threshold for an action to take place