nerve impulse

the transmission of information along a NERVE fibre by electrical activity, which has its basis in the formation of chemical substances and the generation of the action potential. This is a change in electrical potential across the cell membrane (between inside and outside) of an AXON (nerve cell) as an impulse moves along. It is a temporary and localized occurrence caused by a stimulus that travels down the axon, and the voltage is caused by sodium ions (Na + ) entering the axon and changing the potential across the cell membrane from -65mV to +45 mV (millivolts). When the stimulus has passed, the membrane is restored to its resting potential. When a stimulus is continually received, several hundred pulses travel along the nerve per second.