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.
-also known as a nerve impulse is when the membrane potential conducts an impulse. ( not at rest anymore, something trigger electrical impulse on membrane) -When an adequate amount of stimulus excites the membrane, stimulus-gated sodium (Na+) channels open, allowing Na+ to diffuse into the cell at a very fast rate.