By definition, nicotine is a highly addictive central nervous system stimulant. Nicotine behaves in the body much in the way caffeine does. Mainly, it gives you focus, concentration, accelerates your heart rate, breathing rate, and increases blood pressure. Cigarettes and other tobacco products are both physically and psychologically addictive, because they contain a powerful drug called nicotine . Nicotine is a chemical compound present in tobacco. It is absorbed into the bloodstream through mucosal surfaces lining the mouth, nose and airways.
Within the body, nicotine is quickly distributed to all the organs and crossed into the brain via the blood-brain barrier. Nicotine can reach the brain in as little as 7 seconds after being inhaled. Once within the blood stream, nicotine travels to the brain where it binds to and activates receptors called cholinergic receptors. These receptors are abundant in the brain as well as in other areas of the body such as the muscles, heart, adrenal glands and other vital organs. Normally, these receptors are activated by the neurotransmitter acetylcholine which is produced at nerve endings in the brain and in the nerves of the peripheral nervous system.
Acetylcholine stimulation of the receptors is involved in maintaining healthy respiration, heart function and muscle movement as well as cognitive functions such as memory. Since nicotine has a similar structure to acetylcholine, it can activate the cholinergic receptors. However unlike acetylcholine, nicotine disrupts normal brain function, causing chemical changes and addiction. Nicotine dependence, also called tobacco dependence, is an addiction to tobacco products caused by the drug nicotine. Nicotine produces physical and mood-altering effects in your brain that are temporarily pleasing.
These effects make you want to use tobacco and lead to dependence. At the same time, stopping tobacco use causes withdrawal symptoms, including irritability and anxiety. While it’s the nicotine in tobacco that causes nicotine dependence, the toxic effects of tobacco result from other substances in tobacco. When a person smokes a cigarette, the body responds immediately to the chemical nicotine in the smoke. Nicotine causes a short-term increase in blood pressure, heart rate, and the flow of blood from the heart. It also causes the arteries to narrow. Carbon monoxide reduces the amount of oxygen the blood can carry.
This, combined with the effects produced by nicotine, creates an imbalance in the demand for oxygen by the cells and the amount of oxygen the blood is able to supply. When a cigarette is smoked, nicotine-rich blood passes from the lungs to the brain within seven seconds and immediately stimulates the release of many chemical messengers such as acetylcholine, norepinephrine, epinephrine, arginine vasopressin, serotonin, dopamine, and beta-endorphin. This release of neurotransmitters and hormones is responsible for most of nicotines effects. Nicotine appears to enhance concentration and memory due to the increase of acetylcholine.
It also appears to enhance alertness due to the increases of acetylcholine and norepinephrine. Arousal is increased by the increase of norepinephrine. Pain is reduced by the increases of acetylcholine and beta-endorphin. Anxiety is reduced by the increase of beta-endorphin. Nicotine also extends the duration of positive effects of dopamine and increases sensitivity in brain reward systems. At low doses, nicotine potently enhances the actions of norepinephrine and dopamine in the brain, causing a drug effect typical of those of psychostimulants.
At higher doses, nicotine enhances the effect of serotonin and opiate activity, producing a calming, pain killing effect. Nicotine is unique in comparison to most drugs, as its profile changes from stimulant to sedative/pain killer in increasing dosages and use. When you first inhale, nicotine causes your body to release the hormone epinephrine, which is the “fight or flight” hormone. Epinephrine activates the sympathetic nervous system, making your breathing become rapid and shallow, your heart rate increase, and your blood pressure rise.
Nicotine can also lead to insulin sensitivity and insulin resistance, as well as an increased risk of developing metabolic syndrome, type 2 diabetes and cardiovascular disease. It affects thyroid hormones, pituitary hormones, sex hormones and adrenal hormones. Insulin resistance in cigarette smokers may be in part because nicotine stimulates the body to produce high levels of adrenal androgens, in other words, nicotine impacts the bodys glucose metabolism, leading to hyperglycemia and hyperglycemia associated with insulin resistance. Insulin resistance not only increases the risk of developing type 2 diabetes but also heart disease.
Since tobacco and nicotine have different side effects, I will give a brief overview of the harm from tobacco. Tobacco smoking can lead to lung cancer and heart disease as well as many other af? ictions such as bronchitis, emphysema, cataracts, mouth cancer, pancreas cancer, bone density loss, abdominal aortic aneurysm (a sac ballooning out from the blood vessel wall), brain aneurysm gastroesophageal re? ux (recurrent backward ? ow of acid and partially digested food from the stomach to the esophagus, making esophageal cancer more likely).
There are more than 19 cancer causing chemicals in tobacco. Secondhand smoke is just as harmful, if not more harmful that firsthand smoke.
Secondhand smoke contains more than 7,000 chemicals. Hundreds are toxic and about 70 can cause cancer. Secondhand smoke (SHS) is also known as environmental tobacco smoke (ETS). SHS is a mixture of 2 forms of smoke that come from burning tobacco. Sidestream smoke is smoke from the lighted end of a cigarette, pipe, or cigar. Mainstream smoke is the smoke exhaled by a smoker.
Sidestream smoke has higher concentrations of cancer-causing agents (carcinogens) and is more toxic than mainstream smoke. And, it has smaller particles than mainstream smoke. These smaller particles make their way into the lungs and the body’s cells more easily.
When non-smokers are exposed to SHS it’s called involuntary smoking or passive smoking. Non-smokers who breathe in SHS take in nicotine and toxic chemicals by the same route smokers do. The more SHS you breathe, the higher the level of these harmful chemicals in your body. It is said that nicotine is as addictive as heroin, so tobacco users get hooked because of that pleasant feeling or “rush” and often continue to use nicotine to prevent withdrawal symptoms.
Some of the complex factors involved in tobacco and nicotine dependence are how the body handles nicotine, how it is absorbed and removed and how the body responds to it, environmental factors, such as smoking while drinking coffee or after meals, and also physiologic factors, such as a person’s genetic predisposition to addiction. When a person stops smoking, the withdrawal side effects will appear in one to two days, peaking during the first week, and then subsiding within two to four weeks.
Symptoms of nicotine withdrawal include anxiety, cravings, depression, difficulty concentrating, impaired performance, increased appetite and weight gain, irritability, frustration and anger, restlessness and impatience, and sleep disturbances, such as insomnia or sleeping too much.
The probable lethal dose of nicotine has been reported to be between 40 and 60 milligrams On average, a cigarette manufactured in the United States contains about 9mg of nicotine, but this is not the amount of nicotine that is ingested by a smoker. When cigarettes are burned, the smoke is inhaled by the user, so the nicotine enters the lungs and is then absorbed into the body, and then enters the bloodstream. The amount of nicotine actually entering the body is typically less than 1mg. According to the American Academy of Addiction Psychiatry, nicotine dependence is the most common substance use disorder in the United States.
Approximately 60% to 80% of current smokers fulfill classic criteria for drug dependence. They have difficulty stopping, have withdrawals when they stop, and continue despite knowledge of personal harm. Nicotine appears to have a dependence potential equal to that of other drugs. For example, among persons who experiment with alcohol, 10% to 15% will meet criteria for alcohol dependence at some point in their life. Among persons who experiment with cigarettes, 20% to 30% will meet criteria for nicotine dependence in their lifetime. Several different treatment options are available for nicotine withdrawal.
Over-the-counter supplements including gum and skin patches, or prescription nicotine replacement methods such as inhalers and nasal sprays can help reduce symptoms by slowly decreasing the amount of nicotine in your body. Treatment may also include the use of non-nicotine prescription medications such as chantix. Nicotine withdrawal is not a life-threatening condition. However, there may be some physical or mood changes once a person quits smoking. Some people gain weight as a result of stopping smoking due to an increase in appetite or even the need to do something with their hands.
In conclusion, nicotine is a highly addictive stimulant that is almost impossible not to get addicted once a person starts. I started smoking at age 13 and I have been smoking ever since so I know first hand how it pulls you in and makes you stay. It has been 10 years of smoking for me and researching for this assignment has taught me things that I did not know before hand. I am almost positive that my new found insight on the subject could potentially help me quit. Also, if others knew how, what, why, they are addicted to nicotine, it might help them also.
I think a lot of people, myself included, are ignorant to the real issues involved with smoking and nicotine before starting smoking and then they learn more about it after they have already gotten addicted, after it is too late. Bibliography: http://www2. aaap. org/sites/default/files/Policy13. pdf? phpMyAdmin=H6N %2CWzwzCJE-qgHtALaDIa7GNj5.
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