At resting potential, the inside of the cell is slightly negative compared to the outside - Voltage-gated Na+ channels are closed - Hyperpolarize: membrane potential becomes more negative by the efflux K+; makes neuron less sensitive to neurotransmitter Autoimmune Disease of the Nervous System - When myelination breaks down such as with an autoimmune disease like M.S., there would be both a reduction of rate of transmission as well as a lose of action potential along axons Drug Addictions - Stimulants: o Nicotine prevents uptake of dopamine; causes tolerance Has a volume control effect on dopamine, giving user a false sense sense of pleasure as nicotine binds to the dopamine receptors o Effects: Sympathetic nerve pathways, but with many negative metabolic and other health impacts: Hypertension > Inc. heart rate and blood pressure Chronic abuse leads to addiction, psychosis, loss of relationships - Depressants: o Alcohol depletes serotonin, GABA and dopamine. Therefore, people often experience overall loss of motor control o Mood swings are common along with loss of motor control o Negative side effects include
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- Fall '19