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.
Conduction of Nerve Impulse. the transmission of a signal in the form of a wave of excitation within a single neuron or from one cell to another. Conduction of nerve impulses along nerve conductors occurs by means of electrotonic and action potentials, which move along the fiber in both directions without transferring to neighboring fibers.