The Magnificent Breathing Machine 
    
Evangelyn R. Lilly             Ray School
                               5631 S. Kimbark Ave.
                               Chicago IL 60637
                               (312)535-0970

Objective:

Grades 1-3 
   To become aware of the functions  of the lungs in our bodies.
   To become aware that air is made up of gases.
   To become aware that in breathing an exchange of gases takes place in the 
   lungs.

Materials Needed:

     (per person)
   1 clear plastic bottle                clay or play dough
   1 large balloon                       1 plastic straw
   2 small balloons                      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.    

Performance Assessment:                

      The students must construct the model of the human lungs completely in the 
        time allowed.  
      The students will explain each step used to complete their model.
      They will name the gases that compose air.   
      The students will name the gases we exhale.