PSYCHOLOGY CHAPTER 2 STUDY GUIDE BY MATT KENDRA Franz Gall invented phrenology , studies how bumps on your head reflect personality. Neurons are nerve cells consisting of a cell body and 2 types of fibers: dendrites – receive information, axons pas it along. The myelin sheath covers axons and speeds up impulses. The action potential is a brief electrical charge down the axon. The refractory period is a rest between firing, and pumps out sodium ions. Excitatory – pushing accelerator, inhibitory – pushing brake. To trigger an impulse, it has to cross a threshold . Neurons either fire or they don’t in all or none response. A synapse / protoplasmic kiss is a junction of neurons over a synaptic gap . During reuptake , excess neurotransmitters are absorbed. Dopamine influences movement. Serotonin affects mood, hunger, and arousal. Norepinphrine controls arousal. GABA serves inhibitory functions, like sleep disorders. Acetylcholine – affects movement, without it = paralysis. Too much = convulsions.
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