... depends on the context: a world-renowned mathematician is not a reliable source about biology. In general, an article should use the most reliable and appropriate published sources to cover all majority and significant-minority published views." (http://en.wikipedia.org/wiki/Wikipedia:Reliable_sources) SCIENTIFIC BACKGROUND - What is in a cigarette? ((http://www.nysmokefree.com/newweb/pageview.aspx?p=4020) this diagram is more likely to be reliable because the diagram comes from a website that has to do greatly with smoking. Cigarettes contain many ingredients which makes it very addictive and satisfying. These ingredients include: Nicotine - is found in tobacco and is very addictive. Nicotine is delivered to a smoker's lung in the form of mixed smoke particles and gas. The nicotine is then rapidly absorbed into the blood and reaches the brain within about 10 seconds. At this point the smoker experiences a nicotine "hit" - this is when the receptors in the brain produce chemicals called dopamines. The brain soon comes to expect regular doses (or ...

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