A word is one or more sounds that in combination have a specific meaning assigned by a language. The symbolic meaning of words can be so powerful that people are willing to risk their lives for them or take the lives of others.
A nerve impulse is the relaying of a coded signal from a nerve cell to an effector (a muscle cell, a gland cell or another nerve cell) in response to a stimulus. It is the means by which a nerve cell communicates with another cell.
A good definition of a nerve impulse is *a. a transient change in the charge on the membrane of the cell which moves along the length of the neurite. b. a sudden influx of sodium ions. c. a sudden influx of potassium ions. d. a change in membrane potential with a definite time course.