3.4 cells of the nervous system & synapses

• What are the gaps between neurons called?

  Synapses
• How do synapses transmit signals between neurons?

  By means of chemicals called neurotransmitters
• What is the space between neurons called?

  Synaptic cleft
• What do vesicles in the synaptic knob contain?

  Neurotransmitters
• What happens to neurotransmitters after they diffuse across the synaptic cleft?

  They bind to receptors on the post-synaptic membrane
• What is the role of mitochondria in the synaptic knob?

  Provide energy
• What ensures that nerve impulses only travel in one direction?

  Vesicles with neurotransmitters on the pre-synaptic neuron
• What does the frequency of impulses depend on?

  The intensity of the environmental stimulus
• What are the two types of neurotransmitter removal?

  Re-uptake and enzyme degradation
• What must happen to the neurotransmitter after the impulse is transmitted?

  It must be rapidly removed
• What happens if the excitatory effect is greater than the inhibitory effect?

  The impulse is sent
• What determines whether a signal is excitatory or inhibitory?

  The type of receptors on the post-synaptic membrane
• What is required to transmit a nerve impulse?

  A critical number of neurotransmitter molecules
• What does summation refer to in neural pathways?

  Combining a series of weak stimuli
• What neurotransmitter is involved in controlling muscles and memory?

  Acetylcholine
• What is the role of dopamine in the brain?

  Produces feelings of pleasure
• What is GABA's role in the brain?

  Major inhibitory neurotransmitter
• What neurotransmitter is involved in the flight-or-fight response?

  Norepinephrine
• How do endorphins affect pain?

  They relieve pain by blocking signals
• What triggers the production of endorphins?

  Severe injury, exercise, stress, certain foods
• How do endorphins affect GABA production during exercise?

  They inhibit GABA production
• What is the reward pathway activated by?

  Engaging in beneficial behaviors
• What are the functions of key neurotransmitters?

  • Acetylcholine: Controls muscles, regulates memory
  • Dopamine: Produces pleasure, reinforces behavior
  • GABA: Major inhibitory neurotransmitter
  • Glutamate: Most common excitatory neurotransmitter
  • Glycine: Inhibitory neurotransmitter in spinal cord
  • Norepinephrine: Part of flight-or-fight response
  • Serotonin: Involved in mood and sensory perception
• What are the effects of endorphins on mood and behavior?

  • Relieve pain by blocking pain signals
  • Create feelings of well-being
  • Increase during severe injury, exercise, stress, certain foods
• What is the structure and function of neurons?

  • Dendrites: Receive signals
  • Cell body: Contains nucleus and organelles
  • Axons: Transmit impulses away from cell body
  • Myelin sheath: Insulates axons, speeds up transmission
• What is the process of neurotransmitter removal?

  • Re-uptake: Neurotransmitter reabsorbed into presynaptic neuron
  • Enzyme degradation: Neurotransmitter broken down by enzymes
• What is the significance of summation in neural pathways?

  • Combines weak stimuli to reach threshold
  • Triggers nerve impulse if threshold is met
  • Filters out weak stimuli from insufficient neurotransmitter
• What are the effects of dopamine on behavior?

  • Produces feelings of pleasure
  • Activates reward pathway in the brain
  • Reinforces beneficial behaviors
• How does exercise influence endorphin production?

  • Increases endorphin levels
  • Produces feelings of euphoria
  • Inhibits GABA production, enhancing reward pathway
• What is the role of neurotransmitters in mood regulation?

  • Control mood through various pathways
  • Affect emotional responses and behavior
  • Include endorphins and dopamine
• What do endorphins block in the body?

  Receptors
• What happens to endorphin production during extended physical exercise?

  It increases, producing feelings of euphoria
• What neurotransmitter's production is inhibited by endorphins?

  GABA
• What is produced as a result of increased endorphins in the reward pathway?

  Dopamine
• What neurotransmitter produces feelings of pleasure?

  Dopamine
• What does the reward pathway involve?

  Neurons that secrete or respond to dopamine
• When is the reward pathway activated?

  When engaging in beneficial behavior
• What happens to endorphin production during severe pain?

  It increases
• What roles does dopamine play in the brain?

  Behavior, cognition, punishment, motivation, and more
• What is the cell body of a neuron responsible for?

  Containing the nucleus and organelles