Neurons & Synaptic Transmission

• What is the main structure of a neuron called?

  Cell Body
• What does the cell body of a neuron contain?

  The Nucleus
• What is the function of dendrites in a neuron?

  Receives messages from other cells
• What is the role of the axon in a neuron?

  Passes messages away from the cell body
• What does the myelin sheath do?

  Helps speed up electrical impulses
• What are the gaps between Schwann cells called?

  Nodes of Ranvier
• What is the function of axon terminals?

  Forms junctions with other cells
• What are the three types of neurons?

  • Sensory
  • Relay
  • Motor
• What is the function of sensory neurons?

  Sends sensory info to the brain
• Where are sensory neurons found?

  In ganglia in the Peripheral Nervous System
• What is the role of relay neurons?

  Connects sensory and motor neurons
• Where are relay neurons located?

  In the Central Nervous System
• What is the function of motor neurons?

  Sends messages from brain to muscles
• Where are the cell bodies of motor neurons located?

  In the Central Nervous System
• How do motor neurons extend their axons?

  They extend into the Peripheral Nervous System
• What is the charge inside a neuron at rest?

  Negatively charged
• What activates a neuron?

  A stimulus
• What happens to the charge inside the neuron when it is activated?

  It becomes positively charged
• What is the result of the inside of the cell becoming positively charged?

  It causes an action potential
• What happens to the electrical impulse after an action potential is generated?

  It travels down the axon
• Where does the electrical impulse travel towards?

  The axon terminal
• What happens when the electrical impulse reaches the presynaptic terminal?

  It triggers the release of neurotransmitters
• What do neurotransmitters do after being released?

  They diffuse across the synapse
• Where do neurotransmitters bind after diffusing across the synapse?

  To the post-synaptic receptor site
• What is the outcome of neurotransmitters binding to the post-synaptic receptor site?

  The chemical message converts back to an electrical impulse
• In which direction does synaptic transmission occur?

  One direction
• From which neuron are neurotransmitters released?

  Presynaptic neuron
• Which neuron receives the neurotransmitters?

  Post-synaptic neuron
• What are the effects of neurotransmitters on the next neuron?

  • Excitatory Effect:
  • Makes the next neuron positively charged
  • More likely to fire an impulse
  • Inhibitory Effect:
  • Makes the next neuron negatively charged
  • Less likely to fire an impulse