Neuron and synaptic transmission

• What is the junction where two neurons meet called?

  Synapse
• What are the components of a synapse?

  • Presynaptic knob
  • Synaptic cleft
  • Postsynaptic membrane

  
• What does the presynaptic knob contain?

  Vesicles holding neurotransmitters

  
• What is the function of the synaptic cleft?

  It converts electrical signals to chemical messengers

  
• What does the postsynaptic membrane do?

  Receives signals and binds neurotransmitters

  
• What are the steps involved in synaptic transmission?

  1. Electrical impulse in presynaptic neuron
  2. Impulse reaches presynaptic knob
  3. Neurotransmitters released from vesicles
  4. Neurotransmitters diffuse across synaptic cleft
  5. Bind to postsynaptic membrane receptors
  6. Postsynaptic neuron generates action potential
  7. Neurotransmitters destroyed or recycled

  
• What begins the process of synaptic transmission?

  Electrical impulse (action potential)

  
• What happens when the electrical impulse reaches the presynaptic knob?

  Neurotransmitters are released from vesicles

  
• How do neurotransmitters affect the postsynaptic neuron?

  They stimulate it to generate an action potential
• What happens to neurotransmitters after they bind to receptors?

  They are destroyed or recycled
• Why is it important to destroy or recycle neurotransmitters?

  To prevent continued stimulation of the second neuron
• What may happen to re-absorbed neurotransmitters?

  They may be used again by the presynaptic neuron