The end result is the simplest form of etching. There are more complicated ways to create more intricate etchings by using a number of different plates and colors. There is also a process to add different tones to the image that involves adding resin dust to the plate and heating it.
Nerves carry electrochemical signals to and from different areas of the nervous system as well as between the nervous system and other tissues and organs. Nerves are divided into four classes: Cranial nerves connect your sense organs (eyes, ears, nose, mouth) to your brain.
In this way, an electrical impulse moves from a nerve in your stubbed toe to the part of your brain that senses pain. It's also how the SA node tells your heart muscles to contract, how your eyes tell your brain that what they just saw is the word brain, and how you are comprehending this article at all.