TEKS 10 A & B, 11C
Respiratory System
TAKS Objective 2 – The student will demonstrate an understanding of
living systems and the environment.
TEKS Science Concepts 10 A & B
The student knows that, at all level of nature, living systems are found
within other living systems, each with its own boundary and limits. The
student is expected to:
(A) interpret the functions of systems in organisms including
circulatory, digestive, nervous, endocrine, reproductive,
integumentary, skeletal, respiratory, muscular, excretory, and
immune;
(B) compare the interrelationships of organ systems to each other
and to the body as a whole;
11 C
The student knows that organisms maintain homeostasis. The student is
expected to:
(C) analyze the importance of nutrition, environmental conditions, and
physical exercise on health
TAKS Objective 2
page 1
TEKS 7.9 A
For Teacher’s Eyes Only
Teacher Background: There are twelve major organ systems in the human body
(i.e., circulatory, skeletal, respiratory, excretory, integumentary, nervous,
digestive, endocrine, reproductive, immune, lymphatic, and muscular systems). In
this TEKS, we will introduce students to the common structures of each system
and their basic functions. A brief description of these systems follows:
Respiratory System -  REWRITE The primary function of the respiratory
system is to supply the blood with oxygen in order for the blood to deliver oxygen
to all parts of the body. The respiratory system does this through breathing.
When we breathe, we inhale oxygen and exhale carbon dioxide. This exchange of
gases is the respiratory system's means of getting oxygen to the blood.
Respiration is achieved through the mouth, nose, trachea, lungs, and diaphragm.
Oxygen enters the respiratory system through the mouth and the nose. The
oxygen then passes through the larynx (where speech sounds are produced) and
the trachea, which is a tube that enters the chest cavity. In the chest cavity, the
trachea splits into two smaller tubes called the bronchi. Each bronchus then
divides again forming the bronchial tubes. The bronchial tubes lead directly into
the lungs where they divide into many smaller tubes, which connect to tiny sacs
called alveoli. The average adult's lungs contain about 600 million of these
spongy, air-filled sacs that are surrounded by capillaries. The inhaled oxygen
passes into the alveoli and then diffuses through the capillaries into the arterial
blood. Meanwhile, the waste-rich blood from the veins releases its carbon
dioxide into the alveoli. The carbon dioxide follows the same path out of the
lungs when you exhale.
The diaphragm's job is to help pump the carbon dioxide out of the lungs and pull
the oxygen into the lungs. The diaphragm is a sheet of muscles that lies across the
bottom of the chest cavity. As the diaphragm contracts and relaxes, breathing
takes place. When the diaphragm contracts, oxygen is pulled into the lungs. When
the diaphragm relaxes, carbon dioxide is pumped out of the lungs.
Student Prior Knowledge
Students should be familiar with the components associated with body systems
TEKS 6.10 (C) identify how structure complements function at different levels of
organization including organs, organ systems, organisms, and populations and the
functions of these systems.
TAKS Objective 2
page 2
TEKS 7.9 A
Take a Deep Breath
5 E’s
ENGAGE
Obtain a plug from your local butcher shop or J.C. Potter or Owen’s Sausage. A
plug contains the heart and lungs of a newly slaughter hog. Place a large PVC
pipe into the trachea and when students enter the room, demonstrate how air goes
in and out of their lungs. The lungs are very elastic and will expand greatly.
Allow the students to look at the heart, lungs and trachea.
If you do not have the ability to obtain a classroom sample, show the video from
the Xtreem Science website that models how to use the specimen.
TAKS Objective 2
page 3
TEKS 7.9 A
EXPLORE
Explore 1
CONSTRUCT A LUNG MODEL
Make one model with a black balloon with small holes (smoker) and one with a
pink balloon with no holes (non-smoker)
Materials Needed:
(per person)
1 clear plastic bottle
1 large balloon
2 small balloons
clay or play dough
1 plastic straw
2 rubber bands
Strategy:
Explain to the students that they will make a model of their lungs to help them
demonstrate how the lungs and the diaphragm work.
1. Cut the bottom off of the bottle, leaving a portion of the bottom edge on.
2. Cut the top part of a large balloon and discard. Tie the stem of the balloon in a
knot and slip the open end over the bottom of the bottle.
3. Attach the small balloons to the straw with a rubber band and insert the straw,
balloon-side down into the bottle.
4. Seal the top around the straw with clay or play dough.
5. Let the children experiment by pulling down on the knotted balloon. The small
balloons will inflate the same as when you expand your chest and inhale air
through the nose.
6. After practicing with their models, the class will discuss and conclude that
breathing is a mechanical process by which there is an interaction between the
organism and the surrounding air; the lungs and other parts of the respiratory
system perform this mechanical process; that we breathe air (a mixture of gases
composed of oxygen, nitrogen, and a minute amount of carbon dioxide); oxygen,
the gas the body needs, comes from the air; the lungs and other parts of the
respiratory system remove carbon dioxide from the blood as a waste product and
that this excess carbon dioxide is exhaled.
TAKS Objective 2
page 4
TEKS 7.9 A
Explore 2
Measuring Lung Capacity
In this investigation, student will determine the tidal volume and vital capacity of
their lungs.
EXPLAIN
Complete the Respiratory System PowerPoint presentation with discussion
and the completion of the following questions.
TAKS Objective 2
page 5
TEKS 7.9 A
ELABORATE
Elaboration 1
Exhaling
Andrea knows that her breathing rate increases when she starts to run or exercise.
She thinks it is because she needs to increase her oxygen intake. Does increased
activity have an affect on the amount of carbon dioxide she exhales? Design an
experiment that will answer her question.
Materials (per group)
5 drops Bromothymol blue indicator
Eyedropper
50 ml tap water
Graduated cylinder
Drinking straw
100 ml Beakers
3 ml ammonia
Timer with second hand
Safety goggles
Lab apron
Procedure:
1. Use a graduated cylinder to measure 50 ml of tap water and pour into a
beaker.
2. Using the eye dropper, add 5 drops of Bromothymol blue indicator solution to
50 ml of tap water.
3. Gently blow into the solution using the drinking straw until the solution
changes color.
4. Observe changes in the solution.
5. Add 3 ml of a base solution such as ammonia to the tap water solution.
6. Observe changes in the solution.
TAKS Objective 2
page 6
TEKS 7.9 A
Typically the pH of water is between 6 and 8. A pH of 7 is considered to be a
neutral pH. When carbon dioxide is blown into water, carbonic acid, a weak acid
is formed. The chemical bromothymol blue (BTB) can be used to detect the
presence of carbonic acid in water. When carbon dioxide is added to a solution of
BTB, the solution will turn from blue to green, yellow, or pale yellow depending
on the amount of carbon dioxide dissolved in the solution. It is possible to
measure the amount of carbon dioxide by counting the drops of a basic (high pH)
solution it takes to turn the solution back to its original color. This process is
called titration.
1. Explain why the BTB solution turned yellow in the presence of carbon
dioxide. BTB is an indicator of the presence of acid in a solution and the
carbon dioxide dissolved in the water making it acidic.
2. Draw a diagram that illustrates the route air takes as it enters the nose and
moves to the lungs. Then diagram the exchange of oxygen and carbon
dioxide within the lungs. Check students’ illustrations for accuracy.
3. Why does the need for oxygen increase during exercise? Cells need more
energy and oxygen due to oxygen debt.
4. List some sources of error that could occur while conducting this
investigation. Answers vary but may include: you did not inhale or exhale
exactly the same for the different trials, bubbling techniques could vary,
etc.
5. Explain how the muscular, skeletal, circulatory, and the respiratory
systems work together during one inhalation and exhalation. Explanations
should include: Muscle and skeletal – muscles on ribs in the diaphragm
contract and ribs move at joints. Circulatory and respiratory – oxygen and
carbon dioxide exchange takes place at the capillaries surrounding alveoli
in the lungs.
Ask students to suggest an experiment to change the solution back to blue. Write
the proposed experiment in the science journal. Hint: The amount of oxygen and
carbon dioxide in the solution must be changed.
Elaboration 2
Respiratory System Anatomy Coloring Activity
TAKS Objective 2
page 7
TEKS 7.9 A
EVALUATE
1. Monitor students as they design and perform the experiment. Guide class
debriefing using the questions provided in the “Explain” section of this
activity. Student will record information in the scientific journal. A
completion grade will be given.
TAKS Objective 2
page 8
TEKS 7.9 A
TAKS Objective 2
page 9
TEKS 7.9 A
Do-It-Yourself Lung Model
http://student.biology.arizona.edu/sciconn/respiratory/step4.html
Here's what you'll need...
An OLD pair of
scissors (not your
mother's good ones)
Six inches of
surgical tubing
Three good-sized
balloons
Two rubber bands
A large lump of
modeling clay
TAKS Objective 2
page 10
TEKS 7.9 A
A clear plastic oneliter bottle
A three-way hose
connector (available
at the hardware
store)
Step One: Assemble the "lungs"
Push the plastic tube into one
opening of the hose connector.
Use the clay to make an
airtight seal.
Tightly fix a balloon onto each
of the other openings with the
rubber bands, making sure the
seal is airtight.
TAKS Objective 2
page 11
TEKS 7.9 A
Step Two: Prepare the "chest cavity"
Carefully cut off
the bottom 1
inch from the
bottle, using the
scissors. Make
sure the cut edge
of the bottle is
smooth.
Place the lungs
(balloons and
connector)
inside, and seal
the plastic tube
into the neck of
the bottle with
the rest of the
clay to make an
airtight fit.
TAKS Objective 2
page 12
TEKS 7.9 A
Lung Capacity
Overview:
You will determine the tidal volume and the vital capacity of your lungs during this
laboratory investigation.
Materials:
2 round balloons (1 for each student in the pair)
Metric ruler
Meter stick
Procedure:
Tidal Volume:
1. Obtain a round balloon from your teacher and stretch it lengthwise several times.
2. Inhale normally and then exhale normally into the balloon.
3. Be sure to pinch off the end of the balloon to not allow any air to escape. Place
the balloon on a flat surface. Have your partner use the metric ruler to measure
the diameter of the balloon at its widest point. Record this measurement.
4. Deflate the balloon and repeat steps 2 and 3 two more times. Use your three
measurements to calculate an average diameter. Record this number in Data
Table 1.
Vital Capacity:
1. After breathing normally, inhale as much air into your lungs as possible. Exhale
as much air as you can from your lungs into the balloon without taking another
breath.
2. Be sure to pinch off the end of the balloon to not allow any air to escape. Place
the balloon on a flat surface. Have your partner use the metric ruler to measure
the diameter of the balloon at its widest point. Record this measurement.
TAKS Objective 2
page 13
TEKS 7.9 A
3. Deflate the balloon and repeat steps 2 and 3 two more times. Use your three
measurements to calculate an average diameter. Record this number in Data
Table 1.
4. Use the graph below to convert the balloon diameters in your data table into lung
Lung Volume (cubic centimeters)
volumes. On the X axis, locate the diameter of the balloon in centimeters and
follow the number up until it meets the curved line. Then move across in a
straight line to the Y axis and approximate lung volume. Record this number in
Data Table 2. Repeat this procedure for all the balloon diameters in Data Table 1.
9000
8000
7000
6000
5000
4000
3000
2000
1000
0
1
2
3
4
5
6
7
8
9 10 11 12 13
Balloon Diamter (centimeters)
TAKS Objective 2
page 14
TEKS 7.9 A
Data:
Table 1
Table 2
Lung Volume (cm3)
Balloon Diameter (cm)
Trial
Tidal
Volume
Vital
Capacity
Trial
1
1
2
2
3
3
Average
Average
Tidal
Volume
Vital
Capacity
Analysis and Conclusions:
1. When comparing your tidal volume and vital capacity with other
class members did you find any variations? Why might there be
variations among different people?
2. What would you conclude if the balloon were smaller during your
vital capacity measurement than during your tidal volume
measurement?
3. Why was it important to measure tidal volume and vital capacity
more than once and then calculate means for these measurements?
4. Why might a doctor want to determine the tidal volume or vital
capacity of a patient?
TAKS Objective 2
page 15
TEKS 7.9 A
Testing for Carbon Dioxide During Exhalation
Overview:
The term exhalation means “breathing out.” As you have already learned, carbon dioxide
is removed from your body when you exhale.
When carbon dioxide dissolves in water, it combines with hydrogen to form carbonic
acid. This chemical change makes it possible for you to design an experiment that will
detect the presence of carbon dioxide gas in the air that you exhale. In the presence of
acid, a pH indicator changes color. Bromothymol blue is on type of indicator for the
presence of acid. You will blow air bubbles into the water. If the bubbles contain carbon
dioxide, carbonic acid will form when the air meets the water, and the color of the water
will change.
Andrea knows that her breathing rate increases when she starts to run or exercise. She
thinks it is because she needs to increase her oxygen intake. Does increased activity have
an affect on the amount of carbon dioxide she exhales? Design an experiment using the
materials listed below that will answer her question.
Materials (per group)
5 drops Bromothymol blue indicator
Eyedropper
50 ml tap water
Graduated cylinder
Drinking straw
100 ml Beakers
3 ml ammonia
Timer with second hand
Safety goggles
Lab apron
Procedure:
1. Use a graduated cylinder to measure 50 ml of tap water and pour into a beaker.
2. Using the eye dropper, add 5 drops of Bromothymol blue indicator solution to 50
ml of tap water.
3. Gently blow into the solution using the drinking straw until the solution changes
color.
4. Observe changes in the solution.
5. Add 3 ml of a base solution such as ammonia to the tap water solution.
6. Observe changes in the solution.
TAKS Objective 2
page 16
TEKS 7.9 A
Check Sheet for Independent Investigations
I.
II.
III.
IV.
V.
VI.
Stating a problem to investigate
Problem phrased as a research question
If…then hypothesis statement
Develop a procedure to compare baseline heart and
respiration rates to an after exercise heart and
respiration rates.
All steps in sequential order and reproducible
Multiple trials indicated
Materials are appropriate and described
Gathering respiration and heart rate data
Data organized in table or chart
Data has a title
Labels for manipulated & responding variables
Units are stated
Multiple trials, totals and averages are included
Graphing data
Appropriate graph type used
Appropriate scale, range, and interval are used
Graph has a title
Descriptive label for variable on the x-axis and
responding variable for the y-axis
Graphed data matches data collected. Units
indicated for each axis
Data analysis
Results from graph clearly stated
Inferences made about results
Conclusion
Conclusions based on results and inferences
Hypothesis is restated
Hypothesis is accepted or rejected
TAKS Objective 2
page 17
i)
5
15
15
20
20
25
TEKS 7.9 A
Titration Experiment
Typically the pH of water is between 6 and 8. A pH of 7 is considered to be a neutral pH.
When carbon dioxide is blown into water, carbonic acid, a weak acid is formed. The
chemical bromothymol blue (BTB) can be used to detect the presence of carbonic acid in
water. When carbon dioxide is added to a solution of BTB, the solution will turn from
blue to green, yellow, or pale yellow depending on the amount of carbon dioxide
dissolved in the solution. It is possible to measure the amount of carbon dioxide by
counting the drops of a basic (high pH) solution it takes to turn the solution back to its
original color. This process is called titration.
1. Explain why the BTB solution turned yellow in the presence of carbon dioxide.
2. Draw a diagram that illustrates the route air takes as it enters the nose and moves
to the lungs. Then diagram the exchange of oxygen and carbon dioxide within the
lungs.
3. Why does the need for oxygen increase during exercise?
.
4. List some sources of error that could occur while conducting this investigation.
.
5. Explain how the muscular, skeletal, circulatory, and the respiratory systems work
together during one inhalation and exhalation.
TAKS Objective 2
page 18
TEKS 7.9 A
Titration Experiment Elaboration
Suggest an experiment to change the solution back to blue. Write the proposed
experiment in the science journal. Hint: The amount of oxygen and carbon dioxide in the
solution must be changed.
During class discussion record the following information in your scientific journal.
1. Explain why the BTB solution turned yellow in the presence of carbon dioxide.
2. Draw a diagram that illustrates the route air takes as it enters the nose and moves
to the lungs. Then diagram the exchange of oxygen and carbon dioxide within the
lungs.
3. Why does the need for oxygen increase during exercise?
.
4. List some sources of error that could occur while conducting this investigation.
.
5. Explain how the muscular, skeletal, circulatory, and the respiratory systems work
together during one inhalation and exhalation.
TAKS Objective 2
page 19
TEKS 7.9 A