Difference between revisions of "Tobacco"
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== Nicotine == | == Nicotine == | ||
| − | Nicotine is an alkaloid in tobacco that is responsible for the addictive nature of cigarette smoking and other tobacco use. Regular nicotine consumption leads to [[tolerance]] (i.e., higher doses are required to achieve the same effect), and [[withdrawal]] symptoms (e.g., irritability, restlessness, nicotine cravings) occur when use is discontinued. Intake elicits acute increases in heart rate and blood pressure, as well as respiratory rate. Nicotine reaches the brain about seven seconds after it is inhaled in cigarette smoke, and stimulates the release of a number of [[neurotransmitters]], including [[dopamine]], [[norepinephrine]], [[serotonin]], and [[acetylcholine]]. The increased availability of these chemicals in the brain leads to feelings of pleasure and mild euphoria, as well as increased alertness and concentration. The half-life of nicotine is approximately two hours. | + | Nicotine is an alkaloid in tobacco that is responsible for the addictive nature of cigarette smoking and other tobacco use. Regular nicotine consumption leads to [[tolerance]]<ref>Porchet, H. C., Benowitz, N. L., & Sheiner, L. B. (1988). Pharmacodynamic model of tolerance: Application to nicotine. ''Journal of Pharmacology & Experimental Therapeutics, 244'', 231-236</ref> (i.e., higher doses are required to achieve the same effect), and [[withdrawal]]<ref>Hughes, J.R., Higgins, S.T., & Bickel, W.K. (1994). Nicotine withdrawal versus other drug withdrawal syndromes: Similarities and dissimilarities. ''Addiction, 89'', 1461-1470</ref> symptoms (e.g., irritability, restlessness, nicotine cravings) occur when use is discontinued. Intake elicits acute increases in heart rate and blood pressure, as well as respiratory rate. Nicotine reaches the brain about seven seconds after it is inhaled in cigarette smoke, and stimulates the release of a number of [[neurotransmitters]], including [[dopamine]], [[norepinephrine]], [[serotonin]], and [[acetylcholine]]. The increased availability of these chemicals in the brain leads to feelings of pleasure and mild euphoria, as well as increased alertness and concentration. The half-life of nicotine is approximately two hours. |
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| + | Nicotine has also been found to be useful in treating certain disorders. | ||
== Tobacco Products == | == Tobacco Products == | ||
Revision as of 22:49, April 23, 2007
Tobacco is a plant used for smoking. Its recreational qualities were discovered by Native Americans and passed on to Europeans after the establishment of Jamestown in 1607.
History
Tobacco was exported by John Rolfe, (husband of Pocahontas). It became known as a cash crop. The negative effects of tobacco such as lung cancer, bronchitis and foul breath are widely accepted today. Tobacco companies have genetically modified tobacco plants and added toxic chemicals to their products to make them more addictive, thus making the modern cigarette much more toxic than the original cultivated plant.
Nicotine
Nicotine is an alkaloid in tobacco that is responsible for the addictive nature of cigarette smoking and other tobacco use. Regular nicotine consumption leads to tolerance[1] (i.e., higher doses are required to achieve the same effect), and withdrawal[2] symptoms (e.g., irritability, restlessness, nicotine cravings) occur when use is discontinued. Intake elicits acute increases in heart rate and blood pressure, as well as respiratory rate. Nicotine reaches the brain about seven seconds after it is inhaled in cigarette smoke, and stimulates the release of a number of neurotransmitters, including dopamine, norepinephrine, serotonin, and acetylcholine. The increased availability of these chemicals in the brain leads to feelings of pleasure and mild euphoria, as well as increased alertness and concentration. The half-life of nicotine is approximately two hours.
Nicotine has also been found to be useful in treating certain disorders.
Tobacco Products
Cigarettes. Cigarettes are the most commonly used tobacco product. Approximately one of every five American adults is a current smoker[3], and about 438,000 Americans die annually due to the effects of smoking; about 38,000 of these deaths are attributed to secondhand smoke[4]. While the prevalence of smoking has dropped dramatically in the past 50 years, the rate at which the prevalence is decreasing has slowed substantially[5] Additionally, the rate of smoking has been increasing since the mid-1990s[6]. There are nearly 5,000 different chemicals in cigarette smoke, including over 60 carcinogens[7].
Cigars.
Smokeless tobacco.
Health Effects
Smoking has a significant negative health impact, and causes many dangerous and fatal conditions, including cancers, heart disease, and respiratory disease.
It has been estimated that cigarette smoking is responsible for 28% of all deaths in developed countries in the 35-69 age group, as well as 35% of all cancer deaths and 28% of all deaths due to vascular diseases[8]. Smoking increases the risk of oral, pharyngeal, esophageal, laryngeal, lung, uterine, cervical, urinary, and kidney cancers[9].
Coronary heart disease is one of the biggest causes of death in the United States, and is 2-4 more likely in smokers than nonsmokers. Smokers are also 10 times more likely to develop peripheral vascular disease, which is a narrowing of the arteries. Additionally, smokers are twice as vulnerable to a stroke compared with nonsmokers[10] Smoking also negatively impacts the respiratory system. Approximately 90% of all deaths from chronic lung diseases are the result of smoking[11]
Secondhand Smoke
References
- ↑ Porchet, H. C., Benowitz, N. L., & Sheiner, L. B. (1988). Pharmacodynamic model of tolerance: Application to nicotine. Journal of Pharmacology & Experimental Therapeutics, 244, 231-236
- ↑ Hughes, J.R., Higgins, S.T., & Bickel, W.K. (1994). Nicotine withdrawal versus other drug withdrawal syndromes: Similarities and dissimilarities. Addiction, 89, 1461-1470
- ↑ Centers for Disease Control (2005). Cigarette smoking among adults - United States, 2004. Morbidity & Mortality Weekly Report, 54', 1121-1124
- ↑ Centers for Disease Control (2005). Annual smoking-attributable mortality, years of potential life lost, and productivity losses - United States, 1997-2001. Morbidity & Mortality Weekly Report, 54, 300-303.
- ↑ Hughes, J. R., & Brandon, T. H. (2003). A softer view of hardening. Nicotine & Tobacco Research, 5, 961-962.
- ↑ Wechsler, H., Rigotti, N., Gledhill-Hoyt, J., & Lee, H. (1998). Increased levels of cigarette use among college students: A cause for national concern. Journal of the American Medical Association, 280, 1673-1678.
- ↑ Hecht, S. (2006). Cigarette smoking: Cancer risks, carcinogens, and mechanisms. Archives of Surgery, 391, 603-613
- ↑ Hecht, 2006.
- ↑ http://www.cdc.gov/tobacco/health_effects/cancer.htm
- ↑ http://www.cdc.gov/tobacco/health_effects/heart.htm
- ↑ http://www.cdc.gov/tobacco/health_effects/respiratory.htm