Biopsych

• What is the primary means of communication in the nervous system?

  Transmission of signals electrically and chemically
• What are the three types of neurons?

  1. Sensory neurons
  2. Relay neurons
  3. Motor neurons
• What do sensory neurons do?

  Carry messages from PNS to CNS
• Where are sensory neurons located?

  In the PNS in clusters called ganglia
• What is the function of relay neurons?

  Connect sensory neurons to motor neurons
• What percentage of neurons are relay neurons?

  97%
• What do motor neurons connect to?

  CNS to effectors like muscles and glands
• What is the basic structure shared by all neurons?

  Cell body, dendrites, and axon
• What does the cell body (soma) contain?

  A nucleus with genetic material
• What is the function of dendrites?

  Carry nerve impulses towards the cell body
• What does the axon do?

  Carries electrical impulses away from the cell body
• What is the myelin sheath?

  A fatty layer that protects the axon
• What are nodes of Ranvier?

  Gaps in the axon that speed up transmission
• What do terminal buttons do?

  Communicate with the next neuron across the synapse
• What happens when a neuron is in a resting state?

  The inside of the cell is negatively charged
• What occurs when a neuron is activated?

  The inside of the cell becomes positively charged
• What is an action potential?

  An electrical impulse traveling down the axon
• What separates each neuron from the next?

  An extremely tiny gap called the synapse
• How are signals transmitted within neurons?

  Electrically
• How are signals transmitted between neurons?

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

  The electrical impulse reaching the end of the neuron
• What happens to neurotransmitters after crossing the synapse?

  They are taken up by postsynaptic receptor sites
• What is the role of neurotransmitters?

  To diffuse across the synapse to the next neuron
• How do neurotransmitters fit into receptor sites?

  Like a lock and key
• What is the function of acetylcholine?

  Causes muscles to contract
• What effect does serotonin have?

  Affects mood and social behavior
• What type of effect does acetylcholine generally have?

  Excitatory
• What type of effect does serotonin generally have?

  Inhibitory
• What is unique about dopamine?

  It can have excitatory or inhibitory effects
• What must the net effect of neurotransmitters reach?

  A certain threshold to trigger action potential
• What happens if the net effect is inhibitory?

  The postsynaptic neuron is less likely to fire
• What happens if the net effect is excitatory?

  The postsynaptic neuron is more likely to fire
• How does synaptic transmission occur in Sabitha's case with chocolate?

  • Chocolate activates sensory neurons.
  • Signals are transmitted to the CNS.
  • Neurotransmitters are released affecting mood.
  • Resulting in feelings of happiness and pleasure.
• The brain is the most complex organ in the body, with over 100 billion neurons.
• Neurons are specialized cells that transmit information throughout the nervous system through electrical signals called action potentials.