5. Structure of a Neuron Dendrites: Branched fibers that extend outward from the main cell body and carry information into neuron.
6. Structure of a Neuron Soma: Receives information from dendrites. If there is enough stimulation, the message is passed onto the axon
7. Structure of a Neuron Nucleus: central region of the cell body, in which DNA is stored
8. Structure of a Neuron Myelin: A fatty insulation coating some types of neural axons, which speeds conduction of neural impulses.
9. Structure of a Neuron Axon: Conducts information from the cell body to the axon terminals in the form of an electric charge.
10. Structure of a Neuron Axon Terminal Buttons: forms junctions with other neurons through its synaptic vesicles and releases chemicals called neurotransmitters.
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13. Major Neurotransmitters Acetylcholine Found at synapses between neurons and muscle cells as well as in the hippocampus Controls muscle contractions. < acetylcholine = paralysis. > acetylcholine = convulsions and possible death. Dopamine Found in the brain. Voluntary movements, learning and memory, emotional arousal. < dopamine linked to Parkinson’s. > dopamine linked to Schizophrenia leading to hallucinations and emotional disturbances. GABA (Gamma-aminobutyric acid) Helps calm anxiety, eg, by binding to the same receptor sites that are affected by tranquilizing drugs and alcohol. Effect of alcohol is to stimulate release of excess GABA, which causes inhibition of the nervous system associated with getting drunk. Serotonin Found in the lower part of the brain. Involved in mood, appetite and sleep. < linked to anxiety, depression, mood disorders and insomnia. Endorphins Reduces perceptions of pain. Leads to feelings of euphoria, modulation of appetite, release of sex hormones, and enhancement of the immune response. As powerful as morphine.