Nicotine is the natural, highly-addictive substance in tobacco, and it takes as little as seven seconds to reach the brain after you inhale a drag from a cigarette or other device, according to the World Health Organization.
Once it reaches our brains, nicotine can dramatically raise the activity level of feel-good chemical signalers deep in our brain's reward system. This key effect is actually what all abused drugs, including nicotine, appear to have on our brains.
As a result, using nicotine or other addictive drugs doesn't just make us feel euphoric - it also makes us want to use again.
The producers at the infographics site Column Five recently made this graphic to show how quickly and easily our bodies can become primed to use nicotine.
