Chapter 2 pt. 1: Biology, Neurons, and Brain Imagery

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Chapter 2 pt. 1 Biology, Neurons, and Brain
Imagery
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Warm Up - Reading Quiz

• Study until the bell. You will have 7 minutes for
  the reading quiz.

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The Neuron

• The basic building block of the nervous system is
  called the neuron or a nerve cell.

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• Parts of the Neuron
• 1. Dendrites branching extensions that receive
  incoming messages and pass messages toward the
  cell body. (Dendron tree in Greek)

• 2. Soma is the cell body - contains the
  nucleus. (Soma body in Greek)

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Parts of A Neuron

• 3. Axon extension of a neuron which sends
  messages from the soma to other neuron. Longest
  part of the neuron. (Think axis a long line.)
• 4. Terminal Buttons located on end of the
  axon. Release neurotransmitters to communicate
  with other neurons. (Terminal just means
  end)

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Parts of A Neuron

• 5. Myelin Sheath a layer of fatty cells
  encasing the fibers of many axons which allows
  faster transmission speeds in neurons.

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How Does A Neuron Communicate?

• Action Potential neural impulse or brief
  electrical charge that travels down an axon at
  speeds as fast as 200 mph. It happens when you
  feel something. ALL OR NOTHING response (like a
  gun firing).
• Resting Potential refers to the neuron when it
  is not active. Is negatively charged.
• Threshold refers to the minimal level of
  stimulation required for a neural impulse to fire.

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Neuron Communication With Other Neurons

• For two neurons to communicate, the impulse (the
  message) from one must jump over a gap called the
  synapse to the other one.
• Synapse space between the axon which is sending
  the signal and the dendrite which is receiving
  the signal.

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Neuron Communication

• At the end of the axon, the terminal buttons
  release neurotransmitters.
• Neurotransmitters are chemicals that carry
  messages across the synapse. They influence
  whether another neural impulse will take place.
  
• (Epilepsy video)

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• Answer these in your notes
• What is epilepsy?
• 2) How do electrical messages cross the space
  between nerve endings?
• 3) What are the two types of neurotransmitters?
  (Describe what the each do the video didnt say
  their names).

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Types of Neurotransmitters

• GABA helps relax and calm down the body.
• Shortage may cause Anxiety or Epilepsy.

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Types of Neurotransmitters

• 1. A-ce-tyl-cho-line
• Important in learning and memory.
• Best known for allowing muscle contraction.
• Shortage may lead to Alzheimers disease or
  muscular disorders.

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Types of Neurotransmitters

• 2. Serotonin mood, hunger, and arousal.
• Shortage may lead to depression
• 3. Dopamine movement, attention, and emotion.
• Excess may lead to schizophrenia and Parkinsons
  disease.

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Types of Neurotransmitters

• 4. Norepinephrine helps control alertness and
  arousal when you are scared or excited.
• 5. Endorphins The morphine within. Linked to
  pain control and pleasure. (Runners high)

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Agonists vs. Antagonists

• Agonists are chemicals that mimic the effects of
  a neurotransmitter.
• Antagonists are chemicals that block the
  transmission of a neurotransmitter.