Acetylcholine: A neurotransmitter found in both the peripheral nervous system (PNS) and the central nervous system (CNS). In the PNS, it is involved in both muscle contraction as well as that part of the involuntary nervous system involved with "rest and restoration." In the CNS, it is involved with memory function.

Acetylcholine Receptor Subtypes: The two major subtypes include muscarinic and nicotinic, but each has its own multiple subtypes. These are located throughout the nervous system and each subtype is specific for a different type of drug as well as acetylcholine.

Acetylcholinesterase: An enzyme that breaks down acetylcholine, rendering it inactive. Blocking this enzyme leads to a relative increase in acetylcholine.

Acrolein: Responsible for the gummy yellowish residue and acrid smell from burning cigarettes. It is considered carcinogenic and is toxic to the skin. It was used in chemical warfare during World War I.

Adrenal Medulla: The central part of the adrenal gland surrounded by the adrenal cortex. It produces adrenalin (also known as epinephrine), norepinephrine, and dopamine. It responds to stress and is part of the sympathetic, "fight or flight" nervous system.

Adrenergic Receptors: Also known as adrenoreceptors. Alpha- and beta- adrenergic adrenoreceptors are the subtypes of adrenergic receptors responsible for various physiological responses at their site of action. They are part of the sympathetic nervous system.

Alkaloids: Naturally occurring chemical compounds containing basic nitrogen atoms that are produced by a large variety of organisms, including bacteria, fungi, plants, and animals.

Alpha-Bungarotoxin: A snake venom that binds irreversibly to nicotinic acetylcholine receptors at the neuromuscular junction, causing paralysis and death.

Analgesia: A type of drug that relieves pain. Analgesics include nonsteroidal anti-inflammatory (NSAIDs) agents such as aspirin and opiates such as morphine.

Angina Pectoris: (Also known as angina.) Severe chest pain due to a blockage of blood flow in the arteries of the heart. It is a symptom of an impending heart attack.

Anticholinergic: A substance that blocks the effects of acetylcholine in the nervous system. Many of these drugs have side effects, including blurred vision, dry mouth, urinary hesitance, and constipation. It can also cause short- term memory problems.

Arrhythmias: Abnormal heart rhythms.

Atropine: (Also known as the deadly nightshade.) A substance from the plant Atropa belladonna, it blocks muscarinic acetylcholine receptors causing anticholinergic side effects. By blocking these receptors, essentially the parasympathetic action is decreased, leading to a relative increase in sympathetic action.

Attention Deficit Hyperactivity Disorder (ADHD): A persistent pattern of inattention and/or hyperactivity, impulsivity that is seen more frequently in children with ADHD than in children at comparable developmental levels. Other features associated with ADHD are low frustration tolerance, temper outbursts, stubbornness, excessive and frequent insistence on their own requests, labile mood swings, dysphoria, rejection by peers, and poor self-esteem. Academic achievement is often impaired due to being distractible. Conflicts with authority figures (both parents and school personnel) are common. Many of these children also have oppositional defiant disorders. These children may have been exposed to drugs or alcohol in utero. Many ADHD children exhibited low birth weights as newborns. Some teenagers who have ADHD self-medicate with drugs or alcohol.

Axon: That part of the neuron or nerve cell that is a long tube conducting neural signals away from the cell body.


Barbiturates: A class of drugs that affect GABA to prevent seizures from occurring. Used for anxiety disorder until the discovery of benzodiazepines, which were found to be much safer in overdose.

Benzodiazepines: A class of anti- anxiety medications that include the drugs commonly known as Valium and Xanax.

Benzopyrene: A polycyclic aromatic hydrocarbon that is highly carcinogenic and found in tobacco tar. It is also found in charbroiled food and burnt toast.

Bidis: (Also known as Beedis.) A flavored cigarette common to India but exported worldwide. It is especially popular among U.S. teenagers.

Bronchodilator: A drug or chemical that relaxes the smooth muscle of the bronchi and bronchioles to open the airways, allowing more air to reach the lungs. Commonly prescribed in patients with airway diseases such as asthma and COPD.

Bronchus: The large airway of the lungs. No gas exchange between the lungs and the bloodstream occurs here.

Bupropion: Generic name for the drugs Wellbutrin, marketed as an antidepressant, and Zyban, marketed as a smoking cessation medication.


Cannabinoids: A group of compounds found in Cannabis, the marijuana plant, which are responsible for its psychoactive effects.

Carbon Monoxide: A tasteless, odorless, and colorless gas that binds tightly to hemoglobin in a manner similar to oxygen, thereby preventing oxygen from being transported to the organs. Intake of excess carbon monoxide leads to death. It is found in automobile emissions and cigarette smoke.

Catecholamines: Chemicals used as neurotransmitters and produced from the amino acid tyrosine. They include epinephrine, norepinephrine, and dopamine, all of which are produced in the brain as well as in the adrenal medulla, which is part of the sympathetic nervous system.

Chronic Bronchitis: Chronic inflammation of the bronchi that can be caused by an infection but more commonly is the result of COPD and chronic smoking.

Clonidine: A medication commonly prescribed for high blood pressure. It acts on the alpha-2 adrenoreceptors, which regulate the release of norepinephrine in the sympathetic nervous system. By stimulating these receptors, clonidine turns down the amount of epinephrine released and thus lowers blood pressure.

Cognitive Behavioral Therapy (CBT): A type of therapeutic intervention that reinforces "positive thinking" and extinguishes "negative thinking" to change undesirable thought patterns and eventually behaviors. Originally developed to treat depression to change faulty beliefs that cause errors in self-judgment and judgments about life. This therapeutic intervention has been found useful in the treatment of alcoholism and smoking cessation.

Colostrum: The first milk produced late in pregnancy and within the first few days of the baby's birth. It is also known as immune milk as it contains the mother's immunoglobulins, which are proteins from the mother's immune system that aid the infant to fight infection.

Contraindication: A condition or factor that increases the risk of an adverse event when taking a particular medication or receiving a particular treatment. A relative contraindication means that there are possibilities of receiving the medication/treatment without ill effects. An absolute contraindication means that such medication/treatment can never be received.

COPD (Chronic Obstructive Pulmonary Disease): (Also known as chronic airway disease.) A chronic lung condition brought on from cigarette smoking. It leads to a decrease in the lung's ability to oxygenate the body and often is progressive and irreversible.

Cortex: The outer membrane of an organ, such as the cerebral cortex of the brain or the adrenal cortex of the adrenal gland. It is used to identify a different part of an organ, which serves a different function for that organ.

Craving-Generation System: A hypothesized, yet to be proven part of the brain, the function of which is to generate craving for a particular object, such as food or drugs, which are addictive.

Craving-Inhibition System: A hypothesized, yet to be proven part of the brain, the function of which is to inhibit or turn off craving for a particular object, such as food or drugs, which are addictive.

Cytisine: A chemical produced from a variety of plants that has a mechanism of action similar to nicotine. It has been used on occasion in Eastern Europe as a smoking cessation agent. Varenicline is a synthetic analogue of cytisine.

Cytochrome P450 Enzymes: A group of enzymes found in the liver that function to break down chemicals for elimination from the body. These chemicals include but are not limited to medications. Some medications can block these enzymes while other medications or drugs, such as nicotine, can induce or accelerate these enzymes.


DMXB-A: A drug that activates the alpha-7 subtype of the nicotine receptor and is being used experimentally to improve cognition in patients with Alzheimer's disease and schizophrenia.

DNA (Deoxyribonucleic Acid): A type of nucleic acid molecule that contains a code of genetic instructions for the development and functioning in all living organisms and some viruses.

Dopamine: One of the brain's major neurotransmitters, dopamine is responsible for attention, alertness, decision making, reward, pleasure, and elevated mood.

Drug: A compound that, when ingested, alters bodily function in some manner.

Dysphoria: An unpleasant or uncomfortable mood, not necessarily depression, although it could be. It is the opposite of euphoria, a particularly good mood.


Electrochemical: The means by which the nerve conducts signals through the body. Chemical changes lead to electrical changes and vice versa.

Emphysema: A form of COPD where the lung tissue has lost elasticity. This causes the small airways to collapse decreasing the lung's ability to oxygenate the body.

Endorphins: (Also known as endogenous opiates.) A type of natural opiate manufactured by the body after strenuous exercise, laughing, or excitement to act on a variety of physiological changes, including pain perception, appetite suppression, and elevated mood.

Enzyme: A biological molecule that catalyzes or accelerates a chemical reaction. Most enzymes are proteins.

Epibatidine: A chemical produced by an Ecuadorian frog, found on its skin, which is 200 times more potent as an analgesic than morphine but acts on nicotinic acetylcholine receptors.

Epinephrine: (Also known as the hormone adrenaline.) A catecholamine derived from tyrosine, an amino acid, which is produced in the adrenal medulla and released into the bloodstream to activate the "fight or flight" response via the sympathetic nervous system.

Euphoria: An emotion that is a state of intense happiness and feelings of well- being.


FDA (Food and Drug Administration): The Federal Agency devoted to ensuring the safety and effectiveness of all medications released in the United States.

Fenfluramine: A chemical structurally related to amphetamine, but it causes an increase in serotonin and decreases appetite. Fenfluramine was originally released in combination with another chemical as Fen-Phen, a diet pill that was taken off the market in 1997 out of concerns that it affected heart valves.

FEV1 (Forced Expiratory Volume in One Second): Part of a set of measures collectively called pulmonary function tests that allow physicians to measure lung function. FEV1 measures the total volume of air exhaled in one second.

fMRI (Functional Magnetic Resonance Imaging): A type of noninvasive imaging study that allows the observer to visualize the areas of the brain that are functioning after exposure to a particular brain activity.


GABA (Gamma Amino Butyric Acid):

The brain's major inhibitory neurotransmitter. This neurotransmitter dampens all brain activity, essentially calming the brain down at every level.

Ganglion: A mass of tissue, generally nervous, which provides relay points and intermediary connections between different neurological structures in the body, such as the peripheral and central nervous systems.

Ginseng: Literally, "man-root" in Chinese for its distinctive form resembling the legs of a human. It is used in traditional Chinese medicine as a muscle relaxant and stimulant.

Glutamate: The brain's major excitatory neurotransmitter. This neurotransmitter activates all brain activity, essentially stimulating the brain and "lifting" it up at every level. Glycogen: A series of glucose (or sugar) molecules attached together in what is known as a polysaccharide. It is produced and stored in the liver and utilized by the body during times when short bursts of energy are required, such as in the "fight or flight" response.

Gray Matter: The part of the brain that contains the nerve cell bodies, including the cell nucleus and its metabolic machinery, as opposed to the axons, which are essentially the "transmission wires" of the nerve cell. The cerebral cortex contains the gray matter.


Homeostasis: A property of most living systems, which are organized to maintain a stable, balanced state of equilibrium.

Hookah: A water pipe used for smoking tobacco, found principally in Middle Eastern cultures.

Hormone: A chemical produced by the body and released into the bloodstream that has metabolic effects on cells at other sites in the body.

Huntington Disease: An inherited (genetic) disorder affecting the nervous system. It leads to a degeneration of nerves that impact both the motor system and mental functioning. Characteristics are abnormal involuntary motor movements, dementia, and eventually death. It is a neurodegenerative disorder.

Hypercoagulability: A tendency for blood to clot too easily, which can lead to stroke or other types of vascular disease system to the endocrine system via the pituitary gland. It is responsible for certain metabolic processes and other activities of the autonomic nervous system, particularly the sympathetic "fight or flight" response.


Immunoglobulin: An antibody or protein specifically created by white blood cells after they come into contact with a foreign cell or other object. Antibodies fight infections and other dangerous foreign cells such as cancer cells by surrounding the cell so it is eventually expelled from the body or outright killing the abnormal material.


Kava: The extract from a plant found primarily in the Pacific Islands. It is marketed as an herbal medicine against stress, insomnia, and anxiety.


Limbic Area: A set of brain structures that includes the hippocampus, amygdala, and anterior thalamic nuclei that support a variety of functions including emotion, behavior, and long- term memory. These structures are closely associated with the olfactory structures.

Lipolysis: The breakdown of fat stored in fat cells treat respiratory and muscle disorders, and as a purgative. Today it is used to treat asthma and food poisoning, and is often used as part of smoking cessation programs. It is a physical relaxant, and can serve as a nerve depressant, easing tension and panic.


Motivational Interviewing (MI): A brief treatment approach designed to produce rapid internally-motivated change in addictive behavior and other problem behaviors. The core principles are (a) to express empathy, (b) develop discrepancy, (c) avoid augmentation, (d) roll with resistance, and (e) support self- efficacy. MI assumes that ambivalence and fluctuating motivation occur during substance abuse recovery.

Multiple Sclerosis: A neurodegenerative disorder that affects the motor system and leads to weakness, paralysis, and death.

Muscarinic: Referring to muscarine, a chemical that stimulates acetylcholine receptors, located in the brain and the parasympathetic nervous system.


Naltrexone: Generic drug for ReVia. It is an opioid antagonist that competes with narcotics at opiate receptor sites, blocking the opioid analgesics. It is used as an antidote when there is respiratory distress induced by opiate intoxication and to treat opiate addiction.

Nerve (see neuron).

Neuromodulator: A process in which one neuron uses different neurotransmitters to connect to several neurons, as opposed to direct synaptic transmission where one neuron directly reaches another neuron. These transmitters are secreted by a small group of neurons and diffuse through large areas of the nervous system, affecting multiple neurons. Examples of neuromodulators include dopamine, serotonin, acetylcholine, histamine, and others.

Neuromuscular Junction: The junction of the axon terminal of a motor neuron with the muscle fiber responsible for ultimately causing the muscle to contract. In vertebrates, the signal passes through the neuromuscular junction via the neurotransmitter acetylcholine and is a nicotinic receptor.

Neuron: A nerve cell made up of a cell body with extensions called dendrites and the axon.

Neuroplasticity: Changes that occur in the organization of the brain as a result of experience.

Neurotransmitters: Chemicals released by nerves that communicate with other nerves causing electrochemical changes in those nerves to continue to propagate a signal.

Nicotiana rustica: One of the principal nicotine-containing plants that has been cultivated as a source of tobacco. Although it has a higher nicotine content and is harsher, it is used principally for the insecticide industry.

Nicotiana tabacum: The tobacco plant.

Nicotine: A chemical found in a variety of plants that targets a specific group of acetylcholine receptors known as nicotinic receptors.

Nicotinic receptors: Short for nicotinic acetylcholine receptors, they form ion-gated channels in certain neurons. They are located at the neuromuscular junction as well as on the postganglionic sympathetic and parasympathetic nervous system in the body. Stimulation of these receptors causes muscle contraction.

Nitrosamines: Nitrosamines are found in many foods, including beer, fish, and also in meat and cheese products preserved with nitrite pickling salt. They are also produced from grilling and frying food as well as from burning tobacco. Carcinogenic in a wide variety of animal species, a feature suggesting that they may also be cancer-causing in humans.

Norepinephrine: (Also known as noradrenaline.) A neurotransmitter located in the brain as well as a stress hormone released by the adrenal glands. As a stress hormone, also known as epinephrine or adrenaline, this compound affects the "fight or flight" response by activating that part of the involuntary nervous system known as the sympathetic nervous system to increase heart rate, release energy from fat, and increase muscle readiness. As a neurotransmitter, it increases alertness and helps in elevating mood; it also can increase anxiety.

Nortriptyline: Generic drug for Pa- melor, a tricyclic antidepressant medication that is recommended as a second-line non-NRT medication for smoking cessation.

NRT (Nicotine Replacement Therapy): Any type of aid to supplant the nicotine in tobacco use in an effort to wean from nicotine and stop the addiction.

Nuclei: Pleural for nucleus. A membrane-enclosed organelle that contains most of the cell's genetic material in DNA. The function of the nucleus is to maintain the integrity of genetic material and to control the activities of the cell by regulating genetic expression.


Opiate: A type of opioid. An opioid is any agent that binds to opioid receptors, found principally in the central nervous system and gastrointestinal tract. There are four broad classes of opioids: (1) endogenous opioid peptides, produced in the body; (2) opium alkaloids that are plant products, such as morphine (the prototypical opioid) and codeine; (3) semi-synthetic opioids such as heroin and oxycodone; and (4) fully synthetic opioids such as methadone that have structures unrelated to the opium alkaloids. Although the term opiate is often used as a synonym for opioid, it is more properly limited to the natural opium alkaloids and the semi-synthetics derived from them.


Parasympathetic: The part of the peripheral nervous system called the autonomic or involuntary nervous system that controls the body's "rest and restoration" response. (Opposite to the sympathetic nervous system, which controls the body's "fight or flight" response.)

Partial Agonist: A chemical (such as a drug) that can both block and stimulate a receptor depending upon the relative amount of neurotransmitter present in the synaptic cleft. If the amount of neurotransmitter is large, the chemical acts as an antagonist, and if the amount of neurotransmitter is low, the chemical acts as an agonist.

Pathophysiology: The study of physiology focusing on disease processes.

Platelets: (Also known as thrombocytes.) A type of blood cell involved in the cellular mechanisms of the formation of blood clots. Low levels or dysfunction predisposes for bleeding, while high levels, although usually asymptomatic, may increase the risk of the development of a thrombus.

Polynuclear Aromatic Hydrocarbons: Chemicals found in oil, coal, and tar deposits, and are produced as byproducts of fuel burning (whether fossil fuel or biomass), including tobacco. Some of these compounds have been identified as carcinogenic.

Postganglionic: The beginning of the autonomic nervous system, which transmits from the central nervous system to the various organs. Nicotinic receptors are located here.

Preganglionic: The end of the central nervous system as it is communicating with the autonomic nervous system, which is part of the peripheral nervous system.

Psychoactive: A drug or chemical substance that acts on the brain to alter mood, behavior, perception, or consciousness. Abuse of some of these substances may cause addiction.

Psychosis: A state in which an individual experiences hallucinations, delusions, and disorganized thoughts, speech, and/ or behaviors.


Radioactive Carcinogens: Those elements produced by tobacco smoke that are radioactive and therefore carcinogenic.

Receptor: Specific areas of protein on a neuron that are configured to respond only to specific neurotransmitters. Receptors act like locks that only can be opened by specific keys (the neurotransmitters).

Renin: A circulating enzyme that participates in regulating the body's blood pressure.

Reuptake: A transporter protein located presynaptically that serves to transport a neurotransmitter back up into the neuron, essentially ending transmission between two nerves.

Reynaud Syndrome: The result of vascular spasms that decrease blood supply to the respective regions. Smoking worsens the frequency and intensity of attacks, and there is a hormonal component.

Rimonabant: An anti-obesity drug that is an inverse agonist for the cannabinoid receptor CB1. Its main avenue of effect is reduction in appetite. The drug is available only in Europe. There is some suggestion that it may be useful in tobacco cessation and prevention of weight gain associated with smoking.


Schizophrenia: A psychiatric disorder that has symptoms of hallucinations and delusions associated with significant cognitive deficits, particularly in the area of social cognition but also in areas of the brain involving attention, concentration, and planning.

Sensitization-Homeostasis Theory: A theory of addiction involving two complementary systems, the craving-generation system and the craving-inhibition system, which helps to explain how a person can become addicted to tobacco after only a few cigarettes.

Serotonin: One of the brain's major neurotransmitters. Responsible for "vegetative functions" that include sleep, appetite, sex drive (libido), anxiety, and mood.

Sibutramine: (Also known as Meridia). A medication for the treatment of obesity that acts as an appetite suppressant. It is a centrally acting serotonin- norepinephrine reuptake inhibitor structurally related to amphetamines but is not considered to be addictive.

SIDS (Sudden Infant Death Syndrome): (Also known as crib death or cot death.) The leading cause of unexplained death in apparently healthy infants aged one month to one year.

Synapse: The gap between nerves where neurotransmitters are released that allow nerves to communicate with one another.


Tar: That part of tobacco associated with a variety of toxic substances, notably nitrosamines, radioactive elements, acrolein, and polynuclear aromatic hydrocarbons.

TNCO (Tar, Nicotine, and Carbon Monoxide) Ceilings: The total upper value of the aerosol residue, nicotine, and carbon monoxide contents as measured by a cigarette smoking machine calibrated to ISO standards. This measure is used by countries worldwide to regulate manufactured tobacco products.

Trachea: The main airway from the mouth to the bronchi.

Transport Pump: A protein involved in reuptake of neurotransmitters.

Transtheoretical Model: A theoretical model of behavior change. The model involves emotions, cognitions, and behavior, and has several stages of change associated with it, including precontemplation, contemplation, preparation, action, and maintenance.


Up-Regulation: The process by which a cell increases the number of receptors to a given hormone or neurotransmitter to improve its sensitivity to this molecule. (A decrease of receptors is called down- regulation.)


Varenicline: Generic name for Chantix, a medication for smoking cessation. It is a partial nicotine agonist, acting to both stimulate the nicotine receptor as well as block the effects of additional nicotine. Thus, it serves a dual role in treating nicotine withdrawal as well as decreasing the pleasure one would derive from smoking while taking the medication.


White Matter: Nerve tissue in the brain and spinal chord that consists of axons and the sheaths (called myelin) covering the axons to carry nerve impulses between neurons within the nervous system.