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.
Action Potential. Nerve Impulse- begins when a cell becomes stimulated with enough positive ions and fires. This travels down the axon jumping from one node of Ranvier to the next because of the increased insulation provided by the myelin sheath. At the terminal buttons, neurotransmitters will be released.