PSYC 3250 Chapter Notes - Chapter 2: Central Nervous System, Resting Potential, Peripheral Nervous System
13 May 2015
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Document Summary
Neurons are the most important cells of the nervous system. The central nervous system (cns) includes the brain and spinal cord; the peripheral nervous system (pns) includes nerves and some sensory organs. Neurons have four principal parts: dendrites, soma (cell body), axon, and terminal buttons. They communicate by means of synapses, junctions between the terminal buttons of one neuron and the somatic or dendritic membrane of another. When an action potential travels down an axon, its terminal buttons secrete a chemical that has either an excitatory or an inhibitory effect on the neurons with which they communicate. Ultimately, the effects of these excitatory and inhibitory synapses cause behavior, in the form of muscular contractions. Neurons contain a quantity of cytoplasm, enclosed in a membrane. Embedded in the membrane are protein molecules that have special functions, such as the detection of hormones or neurotransmitters or transport of particular substances into and out of the cell.
