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Chemical substance stored in tiny sacs within terminal buttons and involved in carrying information across the synaptic gap to the next neuron
Neurotransmitters
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Each axon breaks out into fibers that end in structures called
terminal buttons
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Sacs within terminal buttons that contain neurotransmitters
Synaptic vesicles
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Some neurotransmitter is reabsorbed into the axon that released it, to await the next neural impulse
Reuptake
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Neuron sending the message
Presynaptic neuron
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Neuron receiving the message
Postsynaptic neuron
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Stimulates firing of neurons involved in muscle action, learning & memory. Deficiency = Alzheimers
ACH or acetycholine
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Keeps too many neurons from firing, so controls precision. Low levels = anxiety
GABA (or gamma amino butyric acid)
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Inhibits firings of CNS neurons. Excites heart muscle, intestines, and urogenital tract. Controls alertness. Too much = manic, too little = depression. Works with ACH to regulate sleep.
Norepinepherine
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Controls voluntary movement. Affects sleep, mood, attention, learning, ability to recognize rewards in environment. Low levels = Parkinsons, deterioration of physical movement.
Dopamine
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Regulation of sleep, mood, attention, learning.
Serotonin
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Neural opiates that stimulate firing of neurons. Shield the body from pain and elevate pleasure
Endorphins
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Hormone/neurotransmitter that regulates love and social bonding. Released right after birth in mother.
Oxytocin.
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Contains a nucleus which directs manufacture of growth & maintenance substances
Cell body
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Parts of a neuron
Cell body, dendrites, axon
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Provides support, nutritional benefits and other functions to neurons
Glial cells
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Tiny spaces between neurons
Synapses
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Once the electrical impulse reaches its threshold, it fires and moves all the way down the axon without losing any of its intensity
All-or-nothing principle
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Brain wave of positive electrical charge that sweeps the axon
Action potential
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The stable, negative charge of an inactive ion
Resting potential
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Electrically charged particles
Ions
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Layer of fat cells that encase and insulate most axons
Myelin sheath
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The part of a neuron that carries information from the cell body toward other cells
Axon
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Treelike fibers projecting from a neuron, which receive information and orient it towards the cell body
Dendrites
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When the charge outside and inside the membrane is closer, the neuron is
Depolarized
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when the ion channels are closed, there's a slight negative charge inside the cell, and a positive charge outside, the neuron is
Resting
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Negatively and positively charged ions will
rush together
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When an incoming impulse raises a neuron's voltage, it becomes
Activated
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When a neuron is activated, its _________ open
Sodium gates
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Powerful stress hormones
Corticosteroids
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Two ions containing positive charges
Sodium & potassium
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Tiny “gates” in the myelin sheath that allow ions to pass into & out of cells
Ion channels
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