How does nicotine affect the body?
Nicotine reaches the brain within ten seconds after smoke enters the lungs and affects the body. Nicotine raises the heart and respiratory (breathing) rates. Nicotine also causes more glucose (blood sugar) to be released into the blood, which may explain why smokers may feel more alert after smoking. Nicotine also causes the brain cells to release unusually larger amount of a chemical called dopamine. Dopamine stimulates pleasures in the brain making the smoker feel good. The effects of nicotine do not last very long. When the effects wear off, the smoker feels strong urge to smoke again to get more nicotine. Repeated doses of nicotine alter the brains activities. The brain reduces the amount of dopamine that it produces. The number of receptors that carry dopamine to the cells is also reduced. When this happens, the smoker needs nicotine just to have normal levels of dopamine in the brain. If the level of dopamine drops, the smoker feels irritable and depressed. Both young and older s
