Lung model
Objective
Build a lung model to show the relationship between the air
pressure in the thorax cavity and the process of inhalation and exhalation.
Materials/apparatus:
Glove, cylindrical plastic container, plastic tube, cellophane
tape, scissors, two small plastic bags, rubber bands.
Procedure
1.
Cut the bottom of the container with scissors.
2.
Cut the plastic bags to the length and that you
desire according to the size of the bottle.
3.
Cut two length of plastic tubes, one long and
one short.
4.
Cut a hole in the middle of the shorter tube,
and fix the mouth of the longer tube onto the hole that you’ve made.
5.
Tie one plastic bag to each end of the Y-tube using
rubber bands.
6.
Carefully insert the other end of the longer
tube through the small opening made in the middle of the cap of the container.
7.
Cut the glove in two and use the part where you
put your fingers.
8.
Stretch the glove sheet under the open bottom of
the container.
9.
Use cellophane tape to hold it in place.
10.
Pull the glove and observe how the plastic bags
attached to the plastic tube change in shape and size.
It may look a bit creepy but sorry because
I can’t find a way to upload the picture I took so I used Paint.
Lung Model Description
In this experiment, the plastic container represents the
thorax cavity, the rubber glove the diaphragm, the plastic bags represent the
lungs, and the Y-tube, the respiratory passageway. When you push and pull the
rubber glove, the plastic bags also inflate and deflate accordingly. When we
breathe, our diaphragm moves; curved in when we exhale, pulled flat when we
inhale. At the same time when we inhale, the intercostals muscles between our
ribs contract and pull the rib cage upwards and outwards. This action increases
the volume of our chest. This also allows the lungs (plastic bags) to expand
and suck in air. When we exhale, our chest muscles and diaphragm relax. This
causes the lung and rib cage to expel air because of the air pressure inside
the thorax cavity that is too high compared to the air pressure outside.
Acknowledgements
My parents helped me the most in this project. They helped
me to ration the time and set targets to accomplish this project (even though I
did it really bad). So yeah, I did it also with the help of my teacher (Pn.
Narina Nissya). Without her, I don’t think I can do this according to the
standards required. Even then, I still do not know if I can reach the
standards. And my friends helped me a lot in giving support and new ideas. So,
thank you to everyone that played a part in this. Thank you.
Source of reference
-my reference book—Focussuper PMR Science
-a website--http://haehee.blogspot.com/2014/01/b6d1e1-tingkatan-3-2014-sains.html
- my own website
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