No nerve endings are really important, which means they can be stimulated and triggered off. Nociceptive fibers have the ability to pick up noxious stimuli like thermal, mechanical and chemical. Once you stimulate a nociceptive neuron, you can send a signal down two major fiber types - A-delta and C-fiber. These can be governed by or graded by how big the axon is. And then how much marination is around it. By doing so, you can speed up the signal.