What is the long fiber that carries the nerve impulses?

AXON

Explanation:

A Long Fibre that CARRIES IMPULSES AWAY FROM THE CELL BODY. Each neuron has only ONE AXON. The Axon Ends in a series of small swellings called AXON TERMINALS. Neurons may have Dozens or even Hundreds of DENDRITES but usually ONLY ONE AXON.

answer( increase) their individual contractile activity;