Section 16.2 Chemicals in Tobacco Products Slide 1 of 16 Objectives Explain how nicotine affects the body. Identify two other dangerous substances in tobacco smoke. Section 16.2 Chemicals in Tobacco Products Examine why smokeless tobacco is not a safe alternative to smoking.

Section 16.2 Chemicals in Tobacco Products Slide 2 of 16 Stimulants are drugs that increase the activity of the nervous system. Nicotine and the Body Once in the blood, nicotine reaches the brain within seconds. By mimicking neurotransmitters, nicotine affects breathing, movement, learning, memory, mood, and appetite.

Section 16.2 Chemicals in Tobacco Products Slide 3 of 16 The major short-term effects of nicotine use are increased heart rate, increased blood pressure, and changes in the brain that may lead to addiction. Nicotine’s Short-Term Effects First-time tobacco users may experience mild signs of nicotine poisoning, which include rapid pulse, clammy skin, nausea, and dizziness. In frequent users, nicotine stimulates the area of the brain that produces feelings of reward and pleasure.

Section 16.2 Chemicals in Tobacco Products Slide 4 of 16 Effects of Nicotine Nervous System Increases activity level Mimics neurotransmitters Decreases some reflex actions Activates the brain’s “reward pathway” Respiratory System Increases mucus production Decreases muscle action in the lungs’ airways Causes breathing to become more shallow Cardiovascular System Increases heart rate and the force of contractions Increases blood pressure Reduces blood flow to skin Increases risk of blood clotting Digestive System Increases saliva production Decreases the amount of insulin released from the pancreas Increases bowel activity

Section 16.2 Chemicals in Tobacco Products Slide 5 of 16 Ongoing use of nicotine causes the body to develop a tolerance to nicotine. Nicotine Addiction The time it takes to become addicted depends on several factors including genetics, frequency of use, and age. Studies show that teens become addicted faster and more intensely than adults. As tolerance increases, nicotine addiction develops.

Section 16.2 Chemicals in Tobacco Products Slide 6 of 16 Tobacco use may become a habit used to cope with stressful situations. Psychological Dependence It may become associated with social situations.

Section 16.2 Chemicals in Tobacco Products Slide 7 of 16 Symptoms of nicotine withdrawal include Nicotine Withdrawal headaches irritability difficulty sleeping inability to concentrate intense nicotine cravings Withdrawal effects may begin as soon as 30 minutes after the last dose of nicotine.

Section 16.2 Chemicals in Tobacco Products Slide 8 of 16

Section 16.2 Chemicals in Tobacco Products Slide 9 of 16 Tobacco smoke contains more than 4,000 chemicals. Other Dangerous Chemicals In addition to nicotine, two of the most harmful substances in tobacco smoke are tar and carbon monoxide.

Section 16.2 Chemicals in Tobacco Products Slide 10 of 16 The dark, sticky substance that forms when tobacco burns is known as tar. Tar Short-term effects of tar brown stains on fingers and teeth smelly hair and clothes bad breath paralysis of cilia lining the airways increased number of respiratory infections impaired lung function Tar contains many chemicals that are known carcinogens, or cancer-causing agents.

Section 16.2 Chemicals in Tobacco Products Slide 11 of 16 When substances—including tobacco—are burned, an odorless, poisonous gas called carbon monoxide is produced. Carbon Monoxide Once inhaled and absorbed into the blood, carbon monoxide binds to the hemoglobin molecules in red blood cells in place of oxygen. Red blood cells cannot transport as much oxygen as the body cells need.

Section 16.2 Chemicals in Tobacco Products Slide 12 of 16 Smokeless tobacco contains many of the same dangerous chemicals that are in tobacco smoke. Chemicals in Smokeless Tobacco stained teeth bad breath and drooling receding gums and tooth decay Smokeless tobacco is at least as addictive as cigarettes. Smokeless tobacco also has a number of short-term effects

Section 16.2 Chemicals in Tobacco Products Slide 13 of 16 Vocabulary stimulantA type of drug that increases the activity of the nervous system. tar A dark, sticky substance that forms when tobacco burns. carcinogen A substance that is known to cause cancer. carbon monoxideA poisonous, colorless, odorless gas produced when substances are burned.

Section 16.2 Chemicals in Tobacco Products Slide 14 of 16 End of Section 16.2 Click on this slide to end this presentation.