Nicotine (cont.)
What are the common street names for nicotine?
You might hear cigarettes referred to as smokes, cigs, or butts. Smokeless
tobacco is often called chew, dip, spit tobacco, or snuff.
How is nicotine used?
Tobacco can be smoked in cigarettes, cigars, or pipes. It can be chewed or,
if powdered, sniffed.
An alternative to cigarettes is "bidis." Originally from India, bidis are
hand-rolled. In the U.S., bidis are popular with teens because they come in
colorful packages with flavor choices. Some teens think that bidis are less
harmful than regular cigarettes. But bidis have even more nicotine, which may
make people smoke more, causing them to be more harmful to the lungs than
cigarettes.
How many teens use nicotine?
More than 3 and one-half million
teens between the ages of 12 and 17 use
tobacco-that's about 15 percent of teens that age. Of those, just over 3
million, or 13 percent, smoke cigarettes. In the U.S., 66.5 million people, or
about 29 percent of the population, use tobacco.
What are the common effects of nicotine?
With each puff of a cigarette, a smoker pulls nicotine into his or her lungs
where it is absorbed into the blood. In eight seconds, nicotine is in the brain,
changing the way the brain works. This process happens so fast because nicotine
is shaped like the natural brain chemical acetylcholine.
Acetylcholine is one of
many chemicals called neurotransmitters that carry messages between brain cells.
Neurons have special spaces called receptors, into which specific
neurotransmitters can fit, like a key fitting into a lock. Nicotine locks into
acetylcholine receptors in different parts of the brain, rapidly causing changes
in the body and brain. Nicotine raises the heart rate and respiration
(breathing) rate, and causes more glucose, or blood sugar, to be released into
the blood. This might be why smokers feel more alert after smoking a cigarette.
Nicotine also attaches to neurons (brain cells) that release a
neurotransmitter called dopamine. Nicotine stimulates neurons to release
unusually large amounts of dopamine. Dopamine stimulates the brain's pleasure
and reward circuit, a group of brain structures called the limbic system
involved in appetite, learning, memory, and feelings of pleasure. Normally,
pleasurable feelings come from food, comfort, and the company of people you
love. But smoking cigarettes causes a flood of dopamine in the smoker's brain.
It's this flood of dopamine that gives the smoker intense feelings of pleasure.
Normally, neurons reabsorb neurotransmitters after they've done their job of
signaling other brain cells. But cigarette smoke causes dopamine to stay in the
spaces between neurons called synapses. Researchers don't yet know exactly what
component of tobacco smoke blocks the reabsorption of dopamine into neurons.
In 40 minutes, half the effects of nicotine are gone. So smokers get the urge
to light up for another dose of the drug. After repeated doses of nicotine, the
brain changes. To adjust to too much dopamine, the brain cuts production of the
neurotransmitter and reduces the number of some receptors. Now, the smoker needs
nicotine just to create normal levels of dopamine in his or her brain. Without
nicotine, the smoker feels irritable and
depressed. The smoker has trained the
limbic system to crave tobacco. Think about how you long for a cold drink on a
hot day. Or how you want a sandwich when you are hungry. Craving for tobacco is
much stronger.
These changes in the brain and body make nicotine highly addictive. Other
addictive drugs of abuse, including heroin and cocaine, cause the same changes
in the brain.
While inhaling a cigarette, smokers are pulling more than nicotine into their
lungs. Tobacco smoke contains more than 4,000 chemicals. Besides nicotine, the
most dangerous chemicals in cigarette smoke are tar and carbon monoxide. Tar
causes lung cancer, emphysema, and bronchial diseases. Carbon monoxide causes
heart problems; smokers are at high risk for heart disease.
Smokers also have a dulled sense of smell and taste, reduced stamina for
exercise and sports, and they smell of smoke. After smoking for a long time,
smokers find that their skin ages faster and their teeth turn brown or
discolored.
Next: Tobacco kills »
- Lung Cancer - Get the facts on lung cancer treatment, diagnosis, staging, causes (smoking), types (adenocarcinoma, squamous cell), prevention, symptoms, warning signs and survival rates.
- Chronic Obstructive Pulmonary Disease - Learn about COPD - Chronic Obstructive Pulmonary Disease which is primarily two related diseases - chronic bronchitis and emphysema.
- Emphysema - Learn about emphysema, a progressive lung disease. Emphysema is a symptom of COPD (chronic obstructive pulmonary disease) with symptoms like shortness of breath, wheezing. Manifestations of COPD include chronic bronchitis, asthma, bronchiectasis, and emphysema.
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