2012高中英语 Module2 Addition素材 外研版必修2VIP专享

AdditionUnderstanding the mythSmoking is not just a bad habit, but a complex addiction. Experts believe that nicotine exerts its powerful addictive effects by altering two chemicals in the brain - dopamine and noradrenaline - known as neurotransmitters. Within seven seconds of inhaling, a concentrated dose of nicotine is delivered directly to the brain, producing a nicotine "rush". Many smokers interpret this rush as one of pleasure, but in reality the pleasure is misunderstood. It only appears pleasurable because it satisfies the craving created by the last cigarette. Over time the smoker has become victim to the classic cycle of addiction. The addictive cycleIf this is hard to believe, think back to the first few cigarettes you smoked. Most smokers will admit that these were anything but pleasurable. In fact, you probably had to persist until the addictive cycle had taken hold before smoking gave you any kind of "pleasure". What smokers perceive as pleasure is, in reality, simply the relief of satisfying a craving for nicotine. After smoking a cigarette, withdrawal can set in as quickly as 15 minutes later. Breaking the addictionDon't be too alarmed though! Despite its addictive nature, nicotine doesn't hang around in your body long (about 48 hours) once you've stopped smoking. For those who choose to go cold turkey, withdrawal symptoms are likely to be at their most intense in the first two or three days and will gradually fade away over the following two or three weeks. For those who simply can't contemplate going cold turkey, research indicates that using nicotine replacement therapy - now available on prescription - can more than double your chances of staying stopped