Download 8164 Digestive Sys CE 8x11

THE HUMAN BODY: SYSTEMS AT WORK
DIGESTIVE SYSTEM:
YOUR PERSONAL
POWER PLANT
Teacher’s Guide
INTRODUCTION
This Teacher’s Guide provides information to help you get the most out of Digestive System: Your
Personal Power Plant. The contents in this guide will allow you to prepare your students before
using the program and present follow-up activities to reinforce the program’s key learning points.
This program examines the processes by which the digestive system acts as a power plant for the
body by turning food into energy. Topics discussed include the process of energy conversion; the
structure and function of the organs of the digestive system; the role of enzymes; and the importance of maintaining a healthy digestive system.
LEARNING OBJECTIVES
After viewing the program, students will be able to:
■ Identify the organs involved in the digestive process and the accompanying accessory
structures.
■ Describe the role of each organ of the digestive system.
■ Understand how the digestive system turns food into energy.
■ Understand how the body uses food as metabolic fuel.
■ Examine the purpose of the food guide pyramid in planning a well-balanced diet.
■ Understand the importance of exercise in maintaining a healthy balance between food intake
and energy output.
■ Examine various diseases related to the digestive system.
EDUCATIONAL STANDARDS
National Standards
This program correlates with the National Science Education Standards from the National
Academy of Sciences, Project 2061 Benchmarks for Science Literacy by the American Association
for the Advancement of Science, and the National Health Education Standards: Achieving Health
Literacy by the Joint Committee on National Health Education Standards. The content has been
aligned with the following educational standards and benchmarks from these organizations.
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Demonstrate the ability to use goal-setting and decision-making skills to enhance health.
Analyze the influence of culture, media, technology, and other factors on health.
Demonstrate the ability to practice health-enhancing behaviors and reduce health risks.
Comprehend concepts related to health promotion and disease prevention.
Understand matter, energy, and organization in living systems.
Understand structure and function in living systems.
Understand personal and community health.
Understand form and function.
Understand systems, order, and organization.
Understand that in many physical, biological, and social systems, changes in one direction
tend to produce opposing (but somewhat delayed) influences, leading to repetitive cycles
of behavior.
■ Understand that most systems above the molecular level involve so many parts and forces and
are so sensitive to tiny differences in conditions that their precise behavior is unpredictable,
even if all the rules for change are known. Predictable or not, the precise future of a system is
not completely determined by its present state and circumstances but also depends on the
fundamentally uncertain outcomes of events on the atomic scale.
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Copyright © 2004 Cambridge Educational®
■ Understand that a system usually has some properties that are different from those of its parts,
but appear because of the interaction of those parts.
■ Understand that a system can include processes as well as things.
■ Understand that thinking about things as systems means looking for how every part relates to
others. The output from one part of a system (which can include material, energy, or information) can become the input to other parts. Such feedback can serve to control what goes on in
the system as a whole.
■ Understand how things work and designing solutions to problems of almost any kind can be
facilitated by systems analysis. In defining a system, it is important to specify its boundaries
and subsystems, indicate its relation to other systems, and identify what its input and its output are expected to be.
■ Understand that any system is usually connected to other systems, both internally and externally. Thus a system may be thought of as containing subsystems and as being a subsystem of
a larger system.
■ Understand that organs and organ systems are composed of cells and help to provide all cells
with basic needs.
■ Understand that for the body to use food for energy and building materials, the food must
first be digested into molecules that are absorbed and transported to cells.
■ Understand that to burn food for the release of energy stored in it, oxygen must be supplied
to cells, and carbon dioxide removed. Lungs take in oxygen for the combustion of food and
they eliminate the carbon dioxide produced. The urinary system disposes of dissolved waste
molecules, the intestinal tract removes solid wastes, and the skin and lungs rid the body of
heat energy. The circulatory system moves all these substances to or from cells where they are
needed or produced, responding to changing demands.
■ Understand that like other animals, human beings have body systems for obtaining and providing energy, defense, reproduction, and the coordination of body functions.
■ Understand that the amount of food energy (calories) a person requires varies with body
weight, age, sex, activity level, and natural body efficiency. Regular exercise is important to
maintain a healthy heart/lung system, good muscle tone, and bone strength.
■ Understand that toxic substances, some dietary habits, and personal behavior may be bad for
one’s health. Some effects show up right away, others may not show up for many years.
Avoiding toxic substances, such as tobacco, and changing dietary habits to reduce the intake
of such things as animal fat increases the chances of living longer.
Reprinted with permission from National Science Education Standards ©1999 by the National Academy of Sciences,
courtesy of the National Academies Press, Washington, D.C.
Advancement of Science, copyright 1993 by the American Association for the Advancement of Science. Used by
permission of Oxford University Press, Inc. Please note: judgments about the alignment of content presented here
with the learning goals in BENCHMARKS FOR SCIENCE LITERACY are those of the author and do not represent the
opinion or endorsement of the AAAS or Oxford University Press, Inc.
This represents the work of the Joint Committee on National Health Education Standards. Copies of National Health
Education Standards: Achieving Health Literacy can be obtained through the American School Health Association,
Association for the Advancement of Health Education or the American Cancer Society. Reprinted with permission.
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English Language Arts Standards
The activities in this Teacher’s Guide were created in compliance with the following National
Standards for the English Language Arts from the National Council of Teachers of English.
■ Use spoken, written, and visual language to accomplish their own purposes (e.g., for learning,
enjoyment, persuasion, and the exchange of information).
■ Employ a wide range of strategies as they write and use different writing process elements
appropriately to communicate with different audiences for a variety of purposes.
■ Use a variety of technological and information resources (e.g., libraries, databases, computer networks, video) to gather and synthesize information and to create and communicate knowledge.
■ Conduct research on issues and interests by generating ideas and questions, and by posing
problems. They gather, evaluate, and synthesize data from a variety of sources (e.g., print and
nonprint texts, artifacts, people) to communicate their discoveries.
Standards for the English Language Arts, by the International Reading Association and the National Council of
Teachers of English, Copyright 1996 by the International Reading Association and the National Council of Teachers
of English. Reprinted with permission.
Technology Standards
The activities in this Teacher’s Guide were created in compliance with the following National
Education Technology Standards from the National Education Technology Standards Project.
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Demonstrate a sound understanding of the nature and operation of technology systems.
Practice responsible use of technology systems, information, and software.
Proficient in the use of technology.
Use technology resources for solving problems and making informed decisions.
Use productivity tools to collaborate in constructing technology-enhanced models, prepare
publications, and produce other creative works.
■ Use technology to locate, evaluate, and collect information from a variety of sources.
The National Education Technology Standards reprinted with permission from the International Society of Technology
Education.
PROGRAM OVERVIEW
This program investigates the workings of the digestive system. Students will learn how food is
converted into life-sustaining energy through a detailed explanation of how the different organs
in the digestive system work. Researchers and physicians provide insightful feedback regarding
contributing factors in weight gain, nutrition, and disease.
MAIN TOPICS
Topic 1: What is the Digestive System?
This section examines the role of food and its contribution to our physical and mental well-being.
It provides an overview of the purpose of the digestive system in changing food to energy, a
comparison of the digestive system to a resource power plant, and an explanation of why energy
is the key to life.
Topic 2: The Organs of the Gastrointestinal Tract
This sections discusses in more detail the organs and accessory structures of the digestive system,
or gastrointestinal tract. The role of glucose levels in stimulating hunger is reviewed, along with
the five elements of digestion and the job of enzymes in breaking down food.
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Topic 3: The Stomach and Small Intestine
This section focuses on the stomach and the small intestine. The anatomy of each organ and its
function in digestion is explained.
Topic 4: Other Key Players
This section explains the role of the pancreas, liver, and gall bladder as key players in the digestive process. The removal of wastes by the large intestine is also discussed.
Topic 5: Nutrition, Exercise, and Disease
The final section focuses on how the body uses food for energy to grow, maintain, and repair
itself. The Food Guide Pyramid is introduced as a visual explanation of a well-balanced diet, one
which meets the nutritional needs of the body. The role of exercise in maintaining a healthy body
is emphasized. Professionals discuss health risks associated with obesity and other diseases of the
digestive system.
FAST FACTS
■ Despite the popular myth, no drownings have ever been attributed to swimming too soon
after eating a meal.
■ The digestive tract is also known as the gastrointestinal (G.I.) tract.
■ The stomach is approximately 10 inches long, and its diameter depends on how much food it
contains. It expands similar to the way a balloon does as it fills with air. When it empties, it
collapses inward on itself like a deflated balloon.
■ When the stomach is full it can hold about one gallon of food.
■ Chewing gum does not stay in the stomach for seven years. Despite popular belief, gum passes through the digestive system within a day or two, just like most other foods.
■ Gastric juices and hydrochloric acid, secreted by the stomach, break down proteins and kill
germs.
■ About 50 tons of food passes through the average person’s digestive system in a lifetime.
■ About one in ten Americans will develop an ulcer in their lifetime.
■ Diabetes is caused by the inability of the pancreas to produce insulin, the hormone our bodies
require to get energy from glucose. In Type 1 diabetes, no insulin is produced; in Type 2, an
insufficient amount is produced.
■ The structures of the small intestine, including the villi, microvilli, and circular folds, help
increase the surface area by almost 600 times.
■ The liver produces bile which helps break down large molecules of fat into smaller droplets,
which can be better absorbed by the body.
■ The liver, gall bladder, and pancreas are not organs of digestion, but the role they play in
cleansing the body of poisons and producing hormones and enzymes necessary for digestion
makes them essential components of the digestive process.
■ The function of the large intestine is to eliminate undigested food residues, mucus, bacteria,
and excess water from the body as feces.
■ The body thrives on carbohydrates, digestible fats called lipids, proteins, vitamins, minerals,
and water.
■ Water makes up 60% of the food we eat, and is considered a nutrient.
■ The Food Guide Pyramid is a visual explanation of what a well-balanced diet looks like. It
emphasizes moderation, variety, and balance.
■ Eating disorders such as bulimia and anorexia nervosa primarily affect women, but are increasingly seen in young men.
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VOCABULARY TERMS
absorption: The passage of digested food from the digestive tract into the cardiovascular and
lymphatic systems for distribution to cells.
anorexia nervosa: A condition characterized by loss of appetite and aversion to food; selfimposed starvation.
appendix: An organ of the digestive system that has no known digestive function, it is 3 to 4
inches long, and is a potential trouble spot for bacteria to accumulate and multiply, resulting in
inflammation.
bile: A bitter, alkaline, yellow or greenish liquid, secreted by the liver, which aids in the absorption and digestion of fats.
bulimia: A condition characterized by an unnaturally constant hunger, resulting in binge eating
and self-induced vomiting.
cecum: The portion of the large intestine from which the appendix opens.
chyme: The semi-fluid mass into which food is converted by gastric secretion and which passes
from the stomach into the small intestine.
colon: The longest part of the large intestine. The colon has four parts: ascending colon, transverse colon, descending colon, and sigmoid colon.
defecation: The elimination of indigestible substances from the body.
digestion: The breakdown of food by chemical and mechanical processes.
digestive system: The system of the body that breaks down food to release energy to be used
by the body.
duodenum: The part of the small intestine where absorption of iron and calcium are most
active.
enzymes: Proteins that help break down food products so the body can digest them.
esophagus: A tube about ten inches long that connects the mouth to the stomach, and
through which the food travels.
ileum: The part of the small intestine where absorption of fats, bile salts, and vitamin B-12
occurs.
jejunum: The part of the small intestine where the complete absorption of proteins and carbohydrates takes place.
kilocalorie: The unit of measurement for energy; it is the measure of fuel for the body.
large intestine: The broad, shorter part of the intestines, comprising the cecum, colon, and rectum. Absorbs water from and eliminates the residues of digestion.
liver: A large reddish-brown glandular organ located in the upper right side of the abdominal
cavity, divided into fissures by five lobes, and functioning in the secretion of bile and various
metabolic processes.
pancreas: A gland situated near the stomach which secretes a digestive fluid into the intestine
through one or more ducts, and which also secretes the hormone insulin.
peristalsis: The body’s major means of propelling food through the digestive system.
saliva: A secretion produced in the mouth that is a combination of mucus and serous fluids.
Saliva assists in the digestive process by moistening food. It contains enzymes that begin to break
down the food.
small intestine: The place where nearly all food absorption occurs, it extends from the pyloric
sphincter to the ileocecal valve. It serves to digest and absorb nutrients.
villi: Folds of the small intestine that allow it to increase its surface area, thereby enabling it to
absorb more nutrients.
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PRE-PROGRAM DISCUSSION QUESTIONS
1. What foods do you eat? How do you think the foods you are eating affect your body?
2. There are many organs and structures in the digestive system. Which organ or structure do
you think is the most important, and why?
3. Why do you think exercise is important in maintaining a healthy body?
4. In what ways does the media affect our body image?
5. How is energy the key to life?
POST-PROGRAM DISCUSSION QUESTIONS
1. Are trendy diets an effective way to lose weight? Discuss the positive and negative effects of
these diets.
2. Do you think the pesticides used on our fruits and vegetables and the hormones being injected into the animals we eat will ultimately cause serious side effects for our bodies? What
problems might be created by our ingestion of these chemicals?
3. One example of a digestive system disorder is irritable bowel syndrome. Stress can affect this
condition. Why do you think stress impacts the digestive system?
4. Explain this statement, “You are what you eat.” Do you believe this is true? Why or why not?
5. Do you think the food you buy from a store is always safe? Why or why not?
6. What attracts you to the foods you buy? Do you read the labels or are you just attracted to
the packaging and advertising? How can you become a more responsible food consumer?
GROUP ACTIVITIES
Health Promotion
Working in small groups, create an advertising campaign to promote good health and nutrition.
Include visuals, catchy slogans, or a short skit to promote your product or idea. Information may
include a display of the Food Guide Pyramid, healthy snacks, the role of exercise in conjunction
with calorie consumption, and the benefits of the product or idea. You can also focus on a specific food group, diet, or health food.
Understanding Disorders
Working with a partner or in small groups, create a role-play involving a character who suffers
from an eating disorder. Be sure to include factual information regarding symptoms of the eating
disorder, situations that might encourage an eating disorder to develop, hardships the person
might experience as they go through their daily activities, and how other people might react to
their disorder. Each group should present their role-play to the other groups.
INDIVIDUAL STUDENT PROJECTS
Modeling the Digestive System
Use modeling clay or other materials to create a three-dimensional model of the digestive system
and its accessory structures. Be sure to label all organs.
Personal Nutrition Journal
Keep a journal for one week to record your daily eating habits. Compare what you eat to the
Food Guide Pyramid. How did your diet measure up to the recommended servings? How can
you change your diet for the better? Which food group(s) do you eat too much of? Which food
group(s) do you need to eat more of? Based on the information you recorded for the week,
create a new diet plan for yourself aimed at improving your personal nutrition.
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INTERNET ACTIVITIES
Find Your BMI
Use the Internet to investigate what a body mass index is, what it is used for, and its accuracy
rate. Then calculate your own BMI. What is the ideal range for a healthy person of your age and
gender? Do you think the BMI is an adequate measurement for overall health and fitness?
Explain your answer.
Demonstration
Create a Power Point presentation to illustrate the voyage of food through the digestive system.
You may include the parts of the digestive system, the path food particles follow while traveling
through the digestive system, or common disorders of the digestive system.
ASSESSMENT QUESTIONS
Q: ____________ is the fuel that gives your body the energy it needs to work and play.
A: Food
Feedback: Food energy enables the body to grow larger and stronger. It also allows you to
repair damaged tissues and produce new cells.
Q: Name three accessory structures that assist the digestive system in changing food into energy.
A: Answer may include the teeth, tongue, salivary glands, liver, gall bladder, and pancreas.
Feedback: Accessory structures, except for the teeth and tongue, lie totally outside the digestive
track and produce or store secretions that aid in the chemical breakdown of food.
Q: How is hunger stimulated?
A: A low blood glucose or sugar level would stimulate hunger because the body is telling you it
needs food to function. When you are finished a meal the blood glucose level goes up, and
the body has a system of hormones to help bring the glucose level back down. At that point
you do not feel hungry anymore.
Feedback: The hypothalamus is the control center for food intake. It has both appetite and satiety centers, which are comprised of clusters of nerves.
Q: The digestive system works with the integumentary system to break down food to be used as
energy and to eliminate waste products that the body cannot use. (True or False)
A: False.
Feedback: The digestive system works with the excretory system. The large intestine is the organ
responsible for ridding the body of any food that cannot be absorbed by the small intestine and
used as energy. It absorbs excess water and eliminates the undigested food residue, mucus, bacteria, and waste from the body as feces.
Q: The___________ is the place where nearly all food absorption occurs.
(a) stomach
(b) pancreas
(c) small intestine
(d) liver
A: (c)
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Feedback: The small intestine is divided into three sections which are distinguished by the location in which substances are absorbed. The duodenum is where the absorption of iron and calcium occurs. The jejunum is where the complete absorption of proteins and carbohydrates takes
place. The ileum is where the absorption of fats, bile salts, and vitamin B-12 occurs. The small
intestine secretes enzymes into the food, breaking it into particles that are small enough to be
absorbed by the blood.
Q: What are the five elements of digestion?
A: Ingestion, digestion, peristalsis, absorption, and defecation
Feedback: Ingestion is the voluntary action of placing food in your mouth. Digestion is the
breakdown of food by chemical and mechanical processes. Peristalsis is the movement of food
along the digestive tract. Absorption is the passage of digested food from the digestive tract into
the cardiovascular and lymphatic systems for distribution to the cells. Defecation is the elimination of indigestible substances from the body.
Q: Why is the liver critical to the body’s ability to survive?
A: The liver is the only organ of the digestive system the body must have to survive. The job of
the liver is to act as a filter for waste products of the body’s bloodstream. It cleanses impurities found in the blood, secretes bile, and breaks down large molecules of fat.
Feedback: The liver manufactures about half of the body’s cholesterol. About 80 percent of the
cholesterol, made by the liver, is used to make bile.
Q: What is the purpose of the Food Guide Pyramid?
A: The Food Guide Pyramid is a visual recommendation for a well-balanced diet.
Feedback: The pyramid teaches us the foundation of our diet should be carbohydrates. As we
move up the pyramid, it includes fruits and vegetables, dairy, and meat. Fats and sweets can be
used in moderation.
Q: Diabetes, heart disease, and high blood pressure are all potential health risks associated with:
(a) ulcers
(b) obesity
(c) kilocalories
(d) retinitis
A: (b)
Feedback: Obesity is the accumulation of excessive body fat. It results from consuming more
calories than the body uses. Genetic and environmental factors influence body weight. A person
is considered obese if their weight is 20 percent or more over the midpoint of their weight range
on a standard height-weight table. An exception to this is if a person is extremely muscular.
Q: Which two diseases of the digestive system are linked to psychological and social factors?
A: Anorexia nervosa and bulimia
Feedback: Anorexia nervosa is a disorder characterized by a distorted body image and an
extreme fear of obesity. It involves self-imposed starvation and appetite loss. Bulimia centers
around binge eating and self-induced vomiting. Chronic consumption of large amounts of food
is followed by purging, rigorous dieting, and excessive exercising. Both disorders involve excessive
concern over body shape and weight.
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ADDITIONAL RESOURCES
WEB SITES
QUIA—Digestive System
www.quia.com/jg/66042.html
Digestive System/ Functions of the Digestive System
www.training.seer.cancer.gov/module_anatomy
Disorders of the Digestive System
www.ener-chi.com/digest.htm
Human Body Systems
www.nsrconline.org/stcms/access/humanbod.htm
The Digestive System
www.8adigest.tripod.com/digestivesystem/
BOOKS
Exploring The Way Life Works: The Science of Biology by Mahlon B. Hoagland, Bert Dodson,
Judith Hauck. Jones & Bartlett Pub. 2001. ISBN: 076371688X
Digestive System by Carol Ballard. Heinemann Library, 2002. ISBN: 1403404518
Digestive System by Pam Walker and Elaine Wood. Gale Group, 2002. ISBN: 1590181506
Dying to Be Thin by Ira M. Sacker and Marc A. Zimmer. Warner Books Incorporated, 1987.
ISBN: 0446384178
OTHER PRODUCTS
Circulatory, Respiratory, Digestive, and Urinary Systems, CD-ROM, Cambridge Educational
This program helps students understand that the human organism has systems dedicated to specific body functions. After completing Part 1 of the CD-ROM Series, students will understand the
function of the circulatory, respiratory, digestive, and excretory systems of the human body. In
addition, they will be introduced to how these systems interact with one another, and how each
system is important to the overall health of a person. (Windows/Macintosh)
Order #: 32696, www.cambridgeeducational.com, 1-800-468-4227
Systems of the Body Poster Set, Cambridge Educational
Simply indispensable in the classroom, this set of ten posters vividly depicts and describes the
human body’s major systems. Each poster features inset illustrations providing highly detailed
looks at key organs and system components, along with “neat-to-know” supplementary facts.
Set includes: Circulatory System, Respiratory System, Digestive System, Urinary System, Endocrine
System, Reproductive System, Lymphatic System, Integumentary System, Nervous System,
Musculoskeletal System
Order #: 33021, www.cambridgeeducational.com, 1-800-468-4227
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Anatomy of the Digestive System Organs— Medical Illustration 1, Poster, The Doe Report
This medical exhibit diagram depicts the major organs of digestion within a generic body outline
including the oral cavity, tongue, glottis, esophagus, stomach, duodenum, liver, small intestine,
large intestine, transverse colon, and rectum.
Order #: exhR0011, www.doereport.com/generateexhibit.php?ID=1874
1-800-338-5954
Digestion and Excretion, VHS/DVD, Visual Learning Company
Concepts and terminology discussed include: nutrients, proteins, enzymes, amino acids, vitamins,
minerals, mechanical digestion, chemical digestion, stomach, intestine, peristalsis, excretion, kidneys, and liver. ©2003
Order #: VLC054VHS, www.visuallearningco.com/correlations/north_carolina/body.shtml
1-800-453-8481
Digestive System Video, VHS/DVD, Ward’s Natural Science
Explore how the organs of the digestive system work together to bring nutrients into the human
body and convert them into forms that our cells can use. Interspersed with the compelling visuals, a dietician examines such topics as calories, the nutritional role of vitamins and minerals, lactose intolerance, and the effects that crash dieting can have on the body’s metabolic rate.
Order #: 193 V 0435, www.wardsci.com/category.asp?start=6&c=1106
1-800-962-2660
Teen Eating Disorders, VHS/DVD, Schlessinger Media
Experts in the field discuss the causes and symptoms of eating disorders, techniques for prevention and detection, and the treatments available.
Order #: E6636, www.libraryvideo.com/sm/teenhealth.asp, 610-645-4000
Nutrition and Diet, VHS/DVD, Schlessinger Media
This program promotes a reasonable, balanced approach to nutrition by following the guidelines
of the food pyramid and getting regular exercise. A registered dietitian and a nutritionist work
with teens to explain the principles of good nutrition and to define healthy eating habits, from
reading product labels and selecting menu items to preparing foods at home.
Order #: E6637, www.libraryvideo.com/guides/solesource.pdf, 610-645-4000
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For information on other programs
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8164