Nerve impulses that pass through the nervous system are able to jump form one neurone to the next. Inside the nerve fiber, the nerve impulse travels as an electrical signal when it reaches the end of the long fiber, it jumps across to the next neurone by means of the chemical transmitter.
This chemical is released from the branched ends of fibre. As this transmitter substance contacts the next neurone, it starts another nerve impulse. This whole process is very fast, and nerve impulses travel along the largest nerve fibres at 90m per second.