The ways in which the words can be meaningfully combined is defined by the language's syntax and grammar. The actual meaning of words and combinations of words is defined by the language's semantics.
A nerve impulse is an electrical signal that travels along an axon. There is an electrical difference between the inside of the axon and its surroundings, like a tiny battery. When the nerve is activated, there is a sudden change in the voltage across the wall of the axon, caused by the movement of ions in and out of the neuron.
the nerve impulse, the sign of activity and the basis of activity in individual neurons in the nervous system. The measure of the activity of an individual nerve cell is indicated by the frequency of its discharge. compound action potential. the sum of the activity in a number of nerve fibers. It applies to the degree of activity in a nerve trunk in which a variable proportion of nerve fibers are discharging.