Synaptic transmission

• What are groups of neurons called?

  Neural networks
• What is the tiny gap between neurons called?

  Synapse
• How are signals transmitted within neurons?

  Electrically
• How are signals transmitted between neurons?

  Chemically across the synapse
• What triggers the release of neurotransmitters?

  Electrical impulse reaching the presynaptic terminal
• What are the tiny sacs that store neurotransmitters called?

  Synaptic vesicles
• What happens to neurotransmitters after they cross the synapse?

  They are taken up by postsynaptic receptor sites
• What do dendrites do in neuron communication?

  Take signals away from the synapse
• What do axons do in neuron communication?

  Take signals to the synapse
• Why can neurotransmitter travel only one way?

  Released from presynaptic neuron, received by postsynaptic neuron
• How many types of neurotransmitters have been identified?

  Several dozen
• What is the relationship between neurotransmitters and receptor sites?

  Neurotransmitters fit into receptor sites like a lock and key
• What is the function of acetylcholine (ACh)?

  Causes muscles to contract
• What effect does serotonin have on the receiving neuron?

  Causes inhibition, making it less likely to fire
• What effect does adrenaline have on the postsynaptic neuron?

  Causes excitation, increasing its positive charge
• What is summation in neuron communication?

  Process of summing excitatory and inhibitory influences
• What determines if a postsynaptic neuron fires?

  The net effect of excitatory and inhibitory signals
• What happens when the postsynaptic neuron becomes positively charged?

  It is more likely to fire an action potential
• What triggers the action potential in the postsynaptic neuron?

  When the sum of signals reaches the threshold