Nerve impulses to and from the brain travel as fast as 170 miles per hour. Do you ever wonder when you get a paper cut or hit your toe on the side of a chair and the pain hurts right away?
It’s due to the super-speedy movement of nerve impulses from your brain to the rest of your body and vice versa, bringing reactions at the speed of a high powered luxury sports car.
And you have three main types of nerve fibers - A, B, and C type. The thicker the nerve fiber, the faster it can send an electrical signal, just like with a wire. The thicker the wire, the more efficient the electricity flow. That's why the fast nerve impulses you mention that are really fast are from A fibers, the thickest which we quickly feel sharp pain and control fast reflexes.
But there is also slow, dull pain such as a toothache which goes along the C fibers which are very thin.