Tobacco and nicotine.
The scientific botanical term of tobacco is nicotiana tabacum.  Tobacco is a plant, four to six feet high with large leaves. The use of the latest is the reason that tobacco is cultivated in a wide range of varieties in temperate regions of the planet. Tobacco is found in wild in Caribbean region, South America and Mexico. Tobacco leaves, after being dried, are used for the production of cigars or if chopped in the manufacture of cigarettes and blends for pipe. The product of the leaves can also be chewed or sniffed. Tobacco smoke is considered an addictive substance, because it contains the chemical nicotine.
Apart from nicotine, tobacco contains over nineteen known chemicals which have been classified as cancer causative factors, collectively known as tar and more than 4,000 other chemicals, including free radicals, acetone, ammonia, carbon monoxide, cyanide, methane, propane and butane.
Nicotine properties and side-effects.
Nicotine is a drug considered highly addictive. Studies have shown that the euphoric and relaxing properties of nicotine are due to the increase of the level of the neurotransmitter dopamine which, in turn, affects the parts of brain that control pleasure. The addiction to nicotine is very complex, because it presents physical and psychological parameters.
Physical side-effects include the occurrence of numerous cravings after smoking cessation. The psychological dependence causes a great desire for the individual to start smoking again.
Nicotine provides an almost immediate result, since it triggers a discharge of epinephrine from the adrenal cortex. This stimulates the central nervous system and, in turn, other endocrine glands, causing a sudden release of glucose. This action results in temporary suppression of the sensation of hunger. In fact, this is the reason why quite a lot of people present increased appetite and may gain weight, after quitting smoking.
Nicotine increases bowel activity and saliva or bronchial secretions. Because of the central nervous system stimulation, nicotine may cause tremors in the inexperienced user or even spasms in high doses. For the same reason, tobacco increases heart rate and blood pressure within the first minute of smoking. This happens because nicotine, apart from constricting arteries, stimulates the brain and the peripheral nervous system. Prolonged periods of smoking may lead to stomach ulceration or gastritis.
Nicotine may also cause sweating, nausea, impaired immunity, diarrhea and gum problems. Nicotine promotes the enhancement of platelet formation which may lead to blood clots. Apart from elevating blood glucose level, nicotine also increases insulin production. Nicotine can be traced in breast milk, in cervix mucous secretions and in amniotic fluid, since it can readily cross the placenta, during pregnancy.
Nicotine, temporarily, stimulates memory and alertness. This is the reason that systematic smokers have significant difficulty to accomplish challenging tasks and reach certain levels of performance without regular smoking.
Absorption and metabolism of nicotine.
Nicotine is absorbed readily in the lungs or through the oral mucosa, when chewed. With frequent use of tobacco, levels of nicotine accumulate in the body during the day and remain overnight. Thus, tobacco users are exposed to the effects of nicotine for twenty four hours a day. Since the metabolism and the secretion of nicotine depend on a variety of factors, the drug may be traced in the body even four days after the last cigarette smoked.
Addiction to nicotine.
Addiction to nicotine results in moderate or severe withdrawal symptoms, when a person tries to quit smoking. When systematic smokers are deprived of nicotine, may present symptoms, such as dizziness, increased anger, hostility, irritability, aggression, frustration, insomnia, restlessness, sleepiness, loss of social cooperation, bulimia, depression, palpitations, headaches, stress, impaired concentration and fatigue. During periods of abstinence and craving, smokers may present impairment in a wide range of mental activities, such as language fluency and comprehension.
The onset of the symptoms occur within the first few hours after cessation, reach a peak after three or four days and usually subside within tree to four weeks. In some cases, the symptoms need two or three months to retreat. |
