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 action potential is repeatedly regenerated along the length of the axon. nerve impulse an electrochemical event that occurs within the neuron. nerve roots the 31 pairs of projections that extend out along each side of the spinal cord; the sites of axons of the sensory and motor neuron s.