Energy in the Human Body

A Middle School Life Science Curriculum

 
Relevant Links
» Important Note
» Lungs animation




Assessments
» Assessment 7.3




Transparencies
» Grape and string analogy
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Investigation 7.3

Gas Exchange in the Lungs

We just compared the inside of lungs to grape-like sacs. This still does not tell us how the oxygen gets out of the alveoli or "grape-like sacs" and into the circulatory system.

Discuss this with your group and see if you can come up with a way. Draw your idea on your whiteboard to share with the class.

Look at the models all the other groups have come up with. Are they different from the model your group drew?

In your lab book make a quick drawing below of your current idea about how oxygen gets from the alveoli into the blood.

Now that you have built a model of the basic structure of the inside of the lungs and have some ideas about how the oxygen gets into the blood, let's try to make a model using the grapes and some string.

Think about this as you look at the grapes and string:

  • Cells need oxygen to conduct cellular respiration. How do they get this oxygen that is in the lungs?
  • How does the oxygen inside the lungs get out to the cells?

PROBLEM TO SOLVE: If we want to get the most air possible out of each alveoli and into the blood stream what would be the mechanism?

With your group make a model to show how the oxygenated blood gets out of the lungs.

Now in your lab book, draw you model of how oxygen moves out of the air sacs (alveoli) of the lungs to go to the cells of the body.

After you have made your model of the interaction between the circulatory system and the lungs, share it with the rest of the class.

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