ASU online, SHS 310 Lab # 1
View the following link: h;ps://www.questacon.edu.au/outreach/programs/science-circus/videos/model-of-lung
If you like you
... [Show More] can make your own model of the respiratory system at home by following the direcJons in the video link.
You will need: scissors, an empty hard sided sports bo;le, play-doh, a pencil, rubber band, a straw, and two medium to
large balloons. It is also possible to use a surgical glove instead of the balloon that goes on the bo;om of the bo;le. (It is
not necessary to make the model – you can just view the video – but some students appreciate the hands-on approach.)
Step 1: If using a balloon, cut off the neck of one balloon. If using a surgical glove, hold it by the cuff end, wrap a
rubber band >ghtly around the base of where the fingers begin. Stretch the balloon or the cuff of the glove over the
cut end of the bo@le, so that about ½ to 3/4” extends around the lip of the bo@le. Set aside.
Step 2: Insert the straw about 2” into the neck of the balloon. Use the rubber band to secure the top of the balloon so
that the straw stays in place. Be sure not to make it too >ght.
Step 3: Roll the play-doh into a ball. Use the pencil to poke a hole through the middle, and remove the pencil. Insert
the end of the straw through the hole in the play-doh. Now, insert the balloon/straw unit (with the balloon end first)
through the narrowed neck opening of the bo@le. Use the play-doh to form a seal around the perimeter of the bo@le
opening and the straw. Voila! Your model is complete.
Answer the following quesJons regarding your lung model. The bo;le represents your ribcage. The surgical glove you
placed on the bo;om represents the diaphragm.
1. What does the intact balloon represent? Lungs
2. What does the straw represent? Airway
Hold the model by the bo;le. Using your other hand, hold the surgical glove (diaphragm) by the rubber band and pull it
down, away from the neck end of the bo;le. What happens to the interior balloon? Circle the correct answers in the
following quesJons.
3. When you pull the diaphragm downward, what happens to the volume inside the bo;le?
It increases / decreases.
4. At the same Jme, what happens to the pressure inside this cavity of the bo;le?
It increases / decreases. This pressure is called: posiJve / negaJve.
5. Now, release the diaphragm. Try pulling in and out a few Jmes. What happens to the interior balloon when you
release it? Why does the air flow out? The interior balloon relaxes and air flows out of the straw due to higher
pressure inside the bo;le.
6. Let’s think about the air pressure in the balloon (alveolar pressure) compared to the atmosphere outside of the
balloon (atmospheric pressure). Before manipulaJng the diaphragm, what is the atmospheric pressure
compared to the alveolar pressure? posiJve / negaJve / equal [Show Less]