How Air Moves In and Out of the Lung

Dorothy Anthony                Luella Elementary 
                               9928 South Crandon Street
                               Chicago IL 60617
                               312-535-6320

Objectives:

To assist pupils in the intermediate grades develop an understanding of
the respiratory system.
 
To demonstrate how air enters and leaves the lungs.

Demonstrate the relationship between the breathing rate and exercise.

Materials needed:

  1. A 1-Liter plastic bottle 
  2. Two 15" balloons
  3. Scissors
  4. Two rubber bands
  5. Watch with a second hand

Strategy:
  
A. Background

    1. Discuss and label the parts of the respiratory system always using our 
       multicultural scientific names which are the same throughout the world.  
       (throat, larynx, trachea, bronchial tube, air sac, lung and diaphragm) 
    2. Trace the path of the air through the respiratory system.
    3. Discuss the process of inhaling and exhaling.

B. Activities

    1. Cut the bottle in half (horizontally).
    2. Place one of the balloons through the opening of the bottle.
    3. Stretch the balloon opening over the bottle opening.
    4. Place a rubber band over the balloon to keep it in place.
    5. Cut the neck off the other balloon and stretch this balloon across the 
       bottom of the bottle. 
    6. Use a rubber band to hold the balloon in place.
    7. Using a watch with a second hand record the breathing rate of a person 
       sitting (1 min.), walking (2 min.), and jogging in place (2 min.). 

Performance Assessment:

     Thinking of the balloon in the opening of the bottle as the lungs and the 
balloon across the bottom of the bottle as the diaphragm, pull down on the 
stretched balloon - record your finding.  Pull very slowly on the stretched 
balloon - record your finding.  Next, pull down faster on the stretched balloon- 
record your finding.  Using the results from your findings to answer the 
following questions: 

    1. What happens to the balloon in the bottle?
                            
    2. How does air move in and out of the lungs?

    3. What large muscle is important in inhaling and exhaling?

    4. Does breathing rate increase with exercise?  

Conclusions:

     The balloon in the bottle opening fills with air when you pull down on the 
stretched balloon across the bottom of the bottle.  When you let go of the 
balloon across the bottom, the air in the balloon in the opening is pushed out.
Air moves in or enters the lungs when the diaphragm moves up (inhaling).  Like 
the heart rate, the breathing rate increases with exercise. 

Reference:
              
 Mallinson, George G.; Mallinson, Jacqueline B.: Smallwood, William
           and Valentino, Catherine. Science. Morristown, N.J. 
           Silver Burdett Company, 1984.