Name: __________________________________________ Date: _____________________
Model Respiratory System Lab
Lungs are important organs in all mammals. Today, you will build your own
respiratory system to show how the lungs, diaphragm, and chest cavity all
work together to make you breathe in and out all day long!
The lungs are part of our respiratory system. As you
learned, this system as 2 jobs.
1. Ventilation – this means moving air in and
out of your lungs
2. Exchanging CO2 and O2 – this is where
carbon dioxide and oxygen switch
places! Oxygen goes in and carbon dioxide
moves out.
Under your lungs is the very strong muscle called the diaphragm. This muscle is
like a flat sheet that separates your lungs from the rest of your abdomen.
Ms. Kelly’s Science - Respiratory System – Lesson 2
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Name: __________________________________________ Date: _____________________
When the muscle is relaxed, it has a dome shape. When it is working, the muscle
flattens out, making the space inside your chest cavity bigger.
DID YOU KNOW?
Your lungs are NOT a muscle! The diaphragm does all of the work!
Your brain sends a signal to your diaphragm to work, and the muscle goes
flat. This PULLS air into your lungs. When the muscle relaxes and pushes
back up, the air in your lungs is PUSHED out.
Ms. Kelly’s Science - Respiratory System – Lesson 2
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Name: __________________________________________ Date: _____________________
Procedure
Step 1: Choose one person in your group to get your basket of materials
Step 2: Check to make sure your basket has all of the following items
- 1 plastic bottle
- Clay
- 1 straw
- Scissors
- 3 elastic bands
- Tape
- 2 balloons ( 1 large, 1 small )
Step 3: Carefully cut your bottle on the line drawn for you.
Step 4: Cut off the bottom of your balloon.
Step 5: Stretch the balloon around the bottom of your plastic bottle. Secure with
tape and rubber bands.
Step 6: Attach the small balloon to the bottom of your straw. Tape it on tightly.
Step 7: Put the straw through the hole in the top of the bottle cap and make an
airtight seal with the clay.
Step 8: Observe what happens to the lungs (balloons inside the bottle) when you
contract the diaphragm (gently pull on the bottom balloon).
Ms. Kelly’s Science - Respiratory System – Lesson 2
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Name: __________________________________________ Date: _____________________
Model Respiratory System Lab – Worksheet
1. Describe what happens when you inhale (when you pull down on the bottom
balloon in your model).
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2. Describe what happens when you exhale (when you let go of the bottom
balloon in your model).
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3. Why do you think some people can inhale more air at one time than others can?
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4. Hypothesize what might happen if you punctured (put a hole in) your chest
cavity?
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_______________________________________________________________
_______________________________________________________________
Ms. Kelly’s Science - Respiratory System – Lesson 2
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Name: __________________________________________ Date: _____________________
5. Get your teacher to put a small hole in your model. Write down what you
observed. Was your hypothesis right or wrong?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
6. Compare your results with those of another group. Were your findings the same
or different? In science, it is important to double check that your findings are
reproducible.
_______________________________________________________________
In the space provided below, draw your model of the respiratory system that
you made! Label each part of the model using the word bank.
Word Bank:
Chest cavity
Lungs
Bronchi
Ms. Kelly’s Science - Respiratory System – Lesson 2
Diaphragm
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