Alcohol s Effects on the Body

Transcription

1 Section 2 Alcohol s Effects on the Body Objectives Before class begins, write the objectives on the board. Have students copy the objectives into their notebooks at the start of class. 1. Focus Warm-Up Health Stats Ask a few volunteers to share their answers. Then ask other volunteers to describe a time when quick reactions helped them avoid a car crash or other accident. Discuss what might have happened if their reaction time had been slowed by alcohol. Tell students they will learn in this section why alcohol slows reaction time and causes other adverse effects. Teaching Transparency W50 Connect to Students might describe such YOUR LIFE effects as slurring words, stumbling, falling down, acting aggressively, and passing out. Section 2 Objectives Summarize the effects of intoxication on the body systems. List four factors that affect blood alcohol concentration. Identify three ways that intoxication may lead to death. Vocabulary intoxication blackout blood alcohol concentration (BAC) hangover driving while intoxicated (DWI) overdose binge drinking 380 Chapter 15 Alcohol s Effects on the Body Health Stats What trend does this graph reveal? Reaction time (milliseconds) How is reaction time the time it takes people to respond to a situation affected by alcohol? Explain how a longer reaction time affects a person s safety on the road. Physical and Behavioral Effects When a person drinks alcohol, the alcohol follows the same pathway through the digestive system as food. But unlike food, alcohol does not have to be digested in the stomach before it is absorbed into the blood. Thus, alcohol gets into a person s bloodstream within minutes of being consumed. Once in the blood, alcohol circulates throughout the body, where it has widespread effects. Effects on Body Systems When people drink alcohol faster than the body can break it down into harmless compounds they become intoxicated. Intoxication is the state in which a person s mental and physical abilities are impaired by alcohol or another substance. Many negative effects on a drinker s body and behavior accompany intoxication by alcohol. Some of these effects are shown in Figure 3. Connect to YOUR LIFE Blood alcohol concentration Think of a movie or book in which a character became intoxicated. Describe the effects. Sensitive Issues Students who have experienced the loss of a classmate, friend, or family member due to drunk driving may be upset by the issue. Be attuned to their needs, and remind students of healthful ways to express grief, such as journal writing. 380 Chapter 15 FYI! Alcohol Use and Risky Behaviors When teens use alcohol, they are also more likely to engage in other risky behaviors. Drinking alcohol increases the risk that a teen will also be in a physical fight or carry a weapon. commit a serious crime such as rape or be the victim of a serious crime. use illegal drugs such as marijuana or cocaine. die from a car crash or drowning. engage in sexual activity, especially unprotected sexual activity. attempt suicide.

2 Effects of Intoxication FIGURE 3 Intoxication has many effects on a drinker s body and behavior. Predicting Which effects would reduce a person s ability to drive safely? Cardiovascular System Heart rate and blood pressure increase. More blood flows to the skin s surface. Core body temperature decreases. Excretory System Kidneys increase urine production. Drinker loses more water from body than usual. Effects on Behavior As intoxication takes effect, drinkers begin to lose judgment and self-control. At the same time, alcohol decreases drinkers natural fears. When these two effects are combined, drinkers may behave in ways they normally would never consider.for example, a person under the influence of alcohol may express anger in violent or destructive ways. Shy people may behave in outgoing ways, and serious people may act foolishly. A person who drinks a lot of alcohol may suffer a blackout. A blackout is a period of time that the drinker cannot recall. Other people may recall seeing the drinker talking, walking, and seemingly in control. The following day, however, the drinker may have no memory of some events from the day before. The drinker may harm others or be harmed during a blackout. Blackouts can happen to first-time drinkers as well as to experienced drinkers. L4 Gifted and Talented Challenge students to learn more about the physiological reasons for the effects of intoxication shown in Figure 3. Have at least one student learn about each system Nervous System Brain activity slows down. Coordination becomes impaired. Sensations and perception become less clear. Reflexes become sluggish. Digestive System Too much alcohol in the stomach may cause vomiting. Alcohol 381 so that all the systems are covered. Suggest that students use a combination of Internet and library sources for their research. Have students present their findings to the class. 2. Teach L3 L2 EL Reading/Note Taking 15-2 Adapted Reading/Note Taking 15-2 Physical and Behavioral Effects EL Building Vocabulary Have students list on a sheet of notebook paper all the unfamiliar terms they encounter as they read this section. Then, ask students to write a definition for each term in English, using their own words. Suggest that they keep the list in their notebook and use it as a personal glossary for the section. L2 Building Vocabulary On the board, write the following word parts and their definitions: in- ( in ), toxic- ( poison ), and -ation ( process ). Ask students to put the word parts together to create a vocabulary term (intoxication) and then define the term (e.g., in the process of being poisoned). Ask: Based on this definition of intoxication, what is alcohol? (a poison) Have students read the definition of intoxication on page 380 and the effects of intoxication in Figure 3. L3 Visual Learning: Figure 3 Teaching Transparency 41 Challenge students to use information in the figure to explain two apparent contradictions about intoxication. Ask: Why does intoxication cause dehydration even though drinkers consume a lot of liquid when they drink? (Intoxication causes the kidneys to produce more urine and the body to lose more water.) Why does intoxication make drinkers feel warmer in cold weather even though they are at increased risk of freezing to death? (Intoxication causes blood to flow to the skin s surface and core body temperature to decrease.) Call on a student to answer the caption question. Caption Answer nervous system effects, such as coordination becoming impaired and reflexes becoming sluggish Alcohol 381

3 Chapter 15, Section 2 Blood Alcohol Concentration L2 Visual Learning: Figure 4 Remind students that the numbers for blood alcohol concentration (BAC) in the figure are percentages. For example, the blood alcohol concentration at which reflexes and alertness decline is 0.02 percent to 0.03 percent. Ask: What percentage of alcohol in the blood may be life threatening? (0.40% or higher) To put these numbers in terms that students might better understand, remind them that 0.40% means fourtenths of one percent and 0.02% means two-hundredths of one percent. L3 Class Discussion Discuss why BAC is a more reliable measure of intoxication than the number of drinks a person has consumed. Then describe various pairs of hypothetical individuals who vary in gender and body size. For each pair, challenge students to predict which individual they think would have the higher BAC if they drank the same amount of alcohol at the same rate on an empty stomach. Ask students to explain their predictions. L3 Online Activity PHSchool.com Use the Web Code to access an online activity about blood alcohol concentration. Have students complete the Web activity. When Blood Alcohol Concentration Is Reflexes and alertness decline. FIGURE 4 As blood alcohol concentration increases, physical and behavioral effects get more and more severe. For: More on blood alcohol concentration Visit: PHSchool.com Web Code: ctd Judgment and self-control are impaired. Reaction time slows Muscle coordination decreases Vomiting usually occurs. Emotions become exaggerated, unstable, or violent. Blood Alcohol Concentration Two people who drink the same amount of alcohol may not be equally affected. Why? The effects of alcohol depend on how much is actually circulating in a person s bloodstream. This amount is termed the blood alcohol concentration (BAC). BAC is the amount of alcohol in a person s blood, expressed as a percentage. For example, a BAC of 0.1 percent means that one-tenth of 1 percent of the fluid in the blood is alcohol. The higher a person s blood alcohol concentration, the more severe the physical and behavioral effects. Blood alcohol concentration is a more reliable measure of intoxication than the number of drinks consumed. Factors Affecting BAC A variety of factors affect a drinker s BAC. You can see the effects of some of these factors in Figure 5. The rate of alcohol consumption, the gender and size of the drinker, and how much food is in the stomach all affect BAC. Rate of Consumption A person s liver chemically breaks down, or metabolizes, alcohol at a fairly constant rate. That rate is about one half to one ounce of alcohol per hour the approximate amount of alcohol in one can of beer, one shot of liquor, or one glass of wine. Therefore, people who have a few drinks in one hour have a higher BAC than people who drink the same amount over several hours. Gender At the same rate and amount of alcohol consumption, males generally will have a lower BAC than females. This is because, for males, a larger portion of the alcohol gets metabolized in the stomach before it enters the bloodstream. In addition, the liver is more efficient at metabolizing alcohol in males. Body Size In general, smaller people by weight and height feel the effects of alcohol more than larger people. They will have a higher BAC after a similar number of drinks. Amount of Food in the Stomach Drinking on an empty stomach increases the rate of alcohol absorption into the bloodstream. A higher BAC will result. 382 Chapter 15 and Health L3 Firsthand Account Based on the information in Figure 4, challenge students to write a first-hand account of how someone might behave if his or her blood alcohol concentration increased over a period of a few hours from 0.00 to 0.20 percent. (Students should give an account of a person who shows increasing effects of intoxication, as listed in Figure 4. They should describe the person as though they were observing the person firsthand.) 382 Chapter 15

4 0.20 Confusion, dizziness, and disorientation occur. Vision and speech are impaired. Blackouts are typical Ability to stand or walk is lost. Loss of consciousness may occur Estimating Blood Alcohol Concentration Number of Drinks* (per hour) Males Loss of consciousness usually occurs. Death may occur. After Drinking Ends Once a person stops drinking, BAC begins to decrease. The intoxicating effects of alcohol slowly diminish, and the person s reflexes and coordination return to normal. Many people refer to this process as becoming sober or sobering up. You may have heard that cold showers, exercise, fresh air, or coffee will help a person sober up more quickly. But this is not true. Nothing can speed the liver s ability to break down alcohol. Fresh air may keep a person awake, but it does not eliminate the intoxicating effects of alcohol. Hangovers Drinking heavily usually causes a person to wake up the next day with a hangover. Hangover is a term used to describe the aftereffects of drinking too much alcohol. Symptoms of a hangover include nausea, upset stomach, headache, and a sensitivity to noise. It is not clear why some drinkers get a hangover and others do not. The only way a person can be sure to prevent one is to avoid alcohol altogether. Connect to YOUR LIFE Your friend says he ll drive you home after he sobers up with a cup of coffee. What do you say? 0.50 and higher Death usually occurs. FIGURE 5 Several factors besides number of drinks affect blood alcohol concentration. Predicting Predict the BAC of a 110-pound woman after she consumes three drinks in one hour *One drink is 1.25 oz of 80-proof liquor, 5 oz of wine, or 12 oz of beer. Females lb lb lb lb lb lb L2 Teacher Demo Show students how the rate of drinking affects BAC. Place a paper coffee filter in a funnel, and rest the funnel in a glass jar. Slowly pour water into the funnel through the filter. Tell students that the filter is like the liver and the water is like alcohol. Now pour the water faster, so it starts to overflow the filter. Tell students that this is like a person drinking too quickly for the liver to break down the alcohol. Ask: What happens to the drinker when that occurs? (The drinker becomes intoxicated.) How can I stop the funnel from overflowing? (Stop pouring water into it or pour more slowly.) How can the drinker become less intoxicated? (Stop drinking or drink over a longer period of time.) L3 Visual Learning: Figure 5 Teaching Transparency 42 Ask: Which three factors affecting BAC are represented in the table? (rate of consumption, gender, and body size) How do BAC estimates for females and males compare? (For the same rate of consumption and body size, females have higher BAC estimates than males.) What is the BAC estimate of a 150- pound man after he consumes five drinks in one hour? (0.12). Using the information in Figure 4, what are the likely effects on his body at this BAC? (vomiting and exaggerated, unstable, or violent emotions) Call on a student to answer the caption question. Make sure students realize that the man has a lower BAC than the woman, even though he drank more than she did in the same amount of time. Caption Answer 0.13 Alcohol 383 Connect to Sample answer: No, thanks. YOUR LIFE A cup of coffee will not help you sober up, so you will still be intoxicated and not fit to drive. L1 Special Needs Have students do a simple hands-on activity to help them understand the concept of blood alcohol concentration (BAC). Give each student two clear plastic cups half full of water, a small bottle of food coloring, a dropper, and a drinking straw. Tell students that the water represents blood and the food coloring represents alcohol. Have students add one drop of food coloring to one cup and thoroughly stir the water with the straw. Then have them add six drops of food coloring to the other cup and thoroughly stir the water. Explain that the water in the first cup is like the blood of a drinker with a low BAC and the water in the second cup is like the blood of a drinker with a high BAC. Alcohol 383

5 Chapter 15, Section 2 Life-Threatening Effects L4 Cooperative Learning Have groups of students find rates of teen car crashes involving alcohol in different areas of their state. Have groups compare and discuss the rates. Ask: Which areas have higher rates and why? (Sample answer: Rates might be higher in rural areas than in urban areas. Possible reasons might include higher speed limits, worse road conditions, and higher rates of teen drinking in rural areas.) Urge students to investigate further and try to identify the most likely reasons for the different rates. Then have the class brainstorm ways to reduce rates of teen car crashes involving alcohol. L3 Addressing Misconceptions Alcohol and Safe Driving Point out that legal does not necessarily mean safe when it comes to alcohol and driving. For example, it is legal in some states for adults to drive with a BAC of 0.06 percent, but this level of alcohol doubles the risk of being involved in a car crash. Because alcohol affects different people differently, there is no truly safe level of alcohol. L2 Building Health Skills Practicing Healthful Behaviors Tell students to assume that some teens at a party are playing a drinking game and getting very drunk. Ask: What would you do if you were at the party? (Sample answers: try to convince them to stop drinking, tell an adult, call 911) Make sure students realize that someone who is very intoxicated is unlikely to listen to reason and may need emergency medical help. Take this opportunity to re-emphasize the seriousness of binge drinking due to the risk of overdose and death. Over one third of teen deaths in motor vehicle crashes are alcohol related. FIGURE 6 Alcohol has a dramatic effect on fatality risk in motor vehicle crashes. 384 Chapter 15 Life-Threatening Effects The short-term effects of intoxication can put a drinker at serious risk. Intoxication increases the risk of death from motor vehicle crashes, alcohol overdose, and interactions of alcohol with other drugs. Motor Vehicle Crashes Alcohol is involved in about 40 percent of fatal motor vehicle crashes. Driving can be impaired by any amount of drinking, even if it falls below legal limits. Alcohol especially impairs the driving skills of underage drinkers. Because of their relative lack of driving experience, underage drivers are already more likely to crash, even without the influence of alcohol. The effects of alcohol and driving inexperience together are a particularly dangerous combination. Driving Under the Influence A driver over age 21 caught driving with a BAC that exceeds the legal limit of 0.08 is charged with driving while intoxicated (DWI). Law enforcement officers often measure BAC with a breath alcohol testing device. The device measures the alcohol level in the breath from the lungs, from which BAC is accurately estimated. Or a blood sample may be drawn and tested directly. People whose BAC is above the legal limit can have their driver s license taken away and can be prosecuted. They may have to pay stiff fines or serve jail time. Zero Tolerance Laws For drivers under the age 21, the law is different. The purchase and possession of alcohol by minors is already illegal. Therefore, there is no acceptable BAC for underage drivers. Laws vary a little from state to state, but in all cases, it is illegal for minors to drive after consuming any amount of alcohol. The penalties for underage drivers may be more strict than those for other drivers. 384 Chapter 15 L3 Focus On ISSUES Debate: Drinking Age Assign several students to represent each side of a debate about whether the minimum drinking age should be lowered to 18. Those arguing for a minimum drinking age of 18 might note that teens who are permitted to drive, join the military, and vote should also be allowed to make their own decisions about drinking. Those arguing against a lower drinking age might point out that there are already many drinking problems on college campuses, and that making drinking legal would only make problems worse. Give students a chance to present the debate in class. After the debate, ask other students to voice their opinions on the issue.

6 Overdose Taking an excessive amount of a drug that leads to coma or death is called an overdose. Alcohol overdose, also called alcohol poisoning, can cause the heart and breathing to stop. Many drinkers assume that they will pass out before drinking a fatal amount. This is not necessarily true. Alcohol continues to be absorbed into the blood for 30 to 90 minutes after a person s last drink. The drinker s BAC can increase even if the drinker becomes unconscious. A person need not be a regular drinker or an alcoholic to die from an overdose. Even someone drinking for the first time can overdose and die from binge drinking. Binge drinking is the consumption of excessive amounts of alcohol at one sitting. Binge drinking is a particular problem among underage drinkers, who may consume many drinks on a bet or dare, or during a drinking game. Binge drinking also affects teens more severely than older drinkers teens enter comas at lower blood alcohol concentrations than adults. Interactions With Other Drugs Sometimes, two drugs can interact to produce effects that are greater than either drug would produce by itself. Recall that alcohol is a depressant drug. When a person drinks alcohol and takes another depressant, such as sleeping pills, the combination can cause drastic changes in the body. Together, the two depressants effects are more than doubled and can dangerously slow breathing and heart rates. In extreme cases, combining alcohol and other depressants leads to coma or death. Warning Signs of Alcohol Poisoning Cold, clammy, pale, or bluish skin Slow or irregular respiration Vomiting while sleeping Cannot be wakened (unconscious) FIGURE 7 If someone you know shows any of these warning signs, contact emergency medical services. 3. Assess Evaluate These assignments can help you assess students mastery of the section content. Section 2 Review Answers appear below. Teaching Resources Practice 15-2 Section 15-2 Quiz L2 Reteach Write the vocabulary terms on the board, and ask students to brainstorm facts about each term. Record the most important facts on the board, and ask students to copy them in their notebooks. Have students reread relevant passages about any terms for which they cannot recall all the important facts. L4 Enrich Teaching Resources Enrich 15-2 Section 2 Review Key Ideas and Vocabulary 1. What is intoxication? 2. Describe the effects of intoxication on four body systems. 3. List four factors that affect blood alcohol concentration. 4. What are three ways that intoxication can lead to death? 5. For drivers over age 21, how is driving while intoxicated (DWI) defined? 6. What is an overdose? How could binge drinking cause an alcohol overdose? Health and Community BAC and Driving Laws Since state governments lowered the legal limit for adult drivers from a BAC of 0.10 to 0.08, thousands of lives have been saved. Is 0.08 low enough? Take a poll of teens and adults in your community. Summarize your findings in a letter to a local politician. Critical Thinking 7. Relating Cause and Effect Teens who use alcohol are more likely to get into fights than those who don t. Relate this fact to the effects of intoxication on the nervous system. 8. Comparing and Contrasting How do drinkingand-driving laws differ for teens and adults? Health and Community BAC and Driving Laws Introduce the activity by having students contrast the effects on behavior when BAC is 0.08 versus when BAC is Students can refer to Figure 4 to review the behavioral effects of different BACs. Caution students to poll only trusted adults they know well. In their letters, students should try to convince a politician to either retain or reduce the legal BAC limit for adult drivers, based on the results of their poll. Alcohol 385 Section 2 Review 1. the state in which a person s mental and physical abilities are impaired by alcohol or another substance 2. Students should list any four of the effects of intoxication (one from each of four body systems) that are given in Figure rate of consumption, gender, body size, and amount of food in the stomach 4. motor vehicle crashes, alcohol overdose, interactions of alcohol with other drugs 5. driving with a BAC that exceeds An overdose is taking an excessive amount of a drug, leading to coma or death. Binge drinking could cause an alcohol overdose because it is the consumption of excessive amounts of alcohol at one sitting. 7. Intoxication leads to loss of judgment and self-control, causing teens who use alcohol to be more likely to get into fights. 8. Adult drivers are charged with a DWI if their BAC exceeds On the other hand, it is illegal for minors to drive after consuming any amount of alcohol. Penalties for underage drivers may also be stricter. Alcohol 385