Tobacco
Tobacco is a product prepared from the leaves of the tobacco plant by curing them. The plant is part of the genus Nicotiana and of the Solanaceae (nightshade) family. While more than 70 species of tobacco are known, the chief commercial crop is N. tabacum. The more potent variant N. rustica is also used around the world.
Tobacco contains the alkaloid nicotine, which is a stimulant. Dried tobacco leaves are mainly used for smoking in cigarettes, cigars, pipe tobacco, and flavored shisha tobacco. They can be also consumed as snuff, chewing tobacco, dipping tobacco and snus.
What Is Tobacco Addiction?
When people are addicted, they have a compulsive need to seek out and use a substance, even when they understand the harm it can cause. Tobacco products — cigarettes, cigars, pipes, and smokeless tobacco — can all be addictive. Everyone knows that smoking is bad for you, and most people that do it want to quit. In fact, nearly 35 million people make a serious attempt to quit each year. Unfortunately, most who try to quit on their own relapse — often within a week.
Nicotine
Nicotine is a chemical compound that is present in tobacco. When tobacco is smoked, nicotine is absorbed through the wall lining of the small air sacs in the lungs. When sniffed or chewed, it is absorbed through the mucous membranes of the nose or mouth. Nicotine can also be absorbed through the skin.
Regardless of how nicotine is absorbed, it enters the bloodstream where it circulates throughout the body and travels to the brain where it crosses the blood-brain barrier. Once in the brain, it binds to and activates receptors called the cholinergic receptors
Is Nicotine Addictive?
Yes. It is actually the nicotine in tobacco that is addictive. Each cigarette contains about 10 milligrams of nicotine. Because the smoker inhales only some of the smoke from a cigarette, and not all of each puff is absorbed in the lungs, a smoker gets about 1 to 2 milligrams of the drug from each cigarette. Although that may not seem like much, it is enough to make someone addicted.