In its pure state, nicotine is a colorless, oily, acrid liquid. It has the chemical formula C10H14N2, and the systematic name 3-(1-methyl-2 pyrrolidyl) pyridine. It is toxic and it turns yellowish brown in air and light. Nicotine has a boiling point of 476°F (247°C). Nicotine is the principal alkaloid in tobacco (Nicotiana tabacum). While the tobacco plant is indigeous to North America, it is now commercially cultivated and naturalized in most sub tropical countries. The word "nicotine" comes from J. Nicot, the man who introduced tobacco to France in the sixteenth century.
Nicotine is present in cigarettes, cigars, pipes, chewing tobacco, and snuff. A stimulant, nicotine increases the pulse rate and blood pressure of the smoker. The initial side effects of nicotine are dizziness and nausea, but nicotine is also highly addictive. Users claim that nicotine aids in relaxation and helps combat anxiety, and it is also an appetite suppressant. Without regular exposure to nicotine, however, users exhibit classic withdrawal symptoms. Nicotine addiction is also very difficult to break; only 20% of those who attempt to quit smoking are successful on their first try.
Like most alkaloids, nicotine exerts its effects at receptors for chemicals that transmit nerve impulses. Specifically, nicotine acts at the nicotinic receptor class for the transmitter acetylcholine. Outside the brain, nicotinic receptors are found primarily in the sympathetic nervous system. Thus, nicotine use triggers sympathetic nervous system effects throughout the body. These effects largely account for nicotine's impact on the user's health. Among nicotine's effects on the human body is constricting small arteries. This raises the blood pressure and makes the heart pump harder, as does the faster heart rate that nicotine produces. Yet, because nicotine also constricts the arteries supplying the heart muscle, the organ receives less blood. When buildups of fatty plaque have already narrowed a person's heart arteries, this may be enough to trigger heart pain (angina) or an actual heart attack. At the same time, elevated blood pressure increases the risk of stroke, with possible disability or even death. Nicotine use may also worsen other circulatory problems, including poor circulation in the hands and feet and some men's difficulty in obtaining an erection. Nicotine in any form should not be used during pregnancy, as it may harm the fetus or cause miscarriage. Nicotine passes into breast milk and may cause problem in nursing babies whose mothers smoke.
Nicotine is also used as an insecticide to control aphids. In such applications, the nicotine is extracted from the stem and the leaf mid ribs of tobacco plants (those sections not used in the manufacture of smoking tobacco)and distilled. Nicotine is a strong, fast acting poison and it is usually applied as a 0.5% solution in water.
This is the complete article, containing 449 words
(approx. 1 page at 300 words per page).
