Short-term Effects
A major reason for the spread and popularity of tobacco since the sixteenth century is connected to one of its short-term effects on the human body. An important active ingredient in tobacco smoke is nicotine , which is rapidly delivered into the bloodstream through the lungs. Nicotine is then transported to receptors in the central nervous system, increasing heart rate and the release of dopamine, a pleasure-inducing chemical. Tobacco smoke also contains chemical substances that increase heart rate and elevate blood pressure, sometimes causing dizziness and tremors because of a reduced flow of oxygenated blood to the brain and extremities