Respiratory System

Mona Turner Delano Elementary School
3937 W. Wilcox
Chicago IL 60624
(312) 534-6620


This lesson was designed for grades 4-6 to show that the general functions
of the respiratory system are to deliver oxygen to the tissues, the importance
of cellular respiration, the processes of inhalation/exhalation, determine the
volume of air exhaled and to eliminate carbon dioxide formed in the body.

Students will:
-Demonstrate that there is oxygen in the air we breathe.
-Build a model of the respiratory system.
-Measure the amount of air that can be forced out of the lungs.
-Demonstrate that carbon dioxide is exhaled from the body.

Materials Needed:

Part A Part B
1. Candle 1. 2-pieces of straw
2. Matches 2. 2-small balloons
3. Pan 3. rubber cement
4. Clear cup or glass 4. 1-large balloon
5. Water 5. rubber bands - 2 small, 1 large
6. tape

Part C Part D
1. Lime powder 1. Plastic dish pan
2. Water 2. 2 feet (61 cm) of aquarium tubing
3. Clear cup or glass 3. 1 gallon (4 liters) plastic milk jug w/cap
4. Straw 4. masking tape
5. pen
6. an 8 oz cup


Part A
This experiment will show that there is oxygen in the air we breathe.
1. Place a small amount of water in the bottom of the pan, enough to cover
the bottom of the pan.
2. Light the candle and place in the water on the bottom of the pan.
3. Cover the lit candle with the glass and observe what happens to the

Part B
This model will show the action of the diaphragm in human respiration.
1. Take a piece of straw about 2 inches in length and cut a small triangle
in the center, but don't go through to the opposite side. Fit one
small balloon over each end of the straw and secure it with a small
rubber band. (Make sure that air will go into each balloon when blown
from the top.)
2. Bend the straw in the middle of the hole.
3. Take a second piece of straw and cut a V-shape on the end. Fit the
slanted points of the straw into each semi-circle of the hole of the
bent straw.
4. Cement the two pieces of the straw together. Allow to dry or use tape
to hold until dry.
5. Cut a hole in the bottom of the clear plastic cup using the diameter of
the straw as a guide to the size. Push the open end of the straw into
the hole of the plastic cup from the inside. Cement the straw into the
6. Take the large balloon and cut the neck off. Carefully stretch the cut
balloon over the opening of the cup. Do not crack the cup. Secure the
edges with the large rubber band. Do not cement the sides of the cup.
The model will only work if there are no leaks.
7. Then pull the bottom balloon gently and observe what happens to the
small balloons.

Part C
This experiment will show that carbon dioxide is one of the major cellular
metabolic waste products.
1. Place about a teaspoon of lime powder in a cup or glass of warm water
and mix thoroughly. Cover the glass and let remain over night.
2. Next day drain the clear fluid off the top of the solution. This is
the lime water for the experiment.
3. Place the straw in the lime water and blow into the straw. Observe
what happens to the clear fluid.

Part D
This experiment will demonstrate lung capacity by measuring the amount of air
that can be forced out of the lungs.
1. Place a strip of masking tape down the side of the milk jug from the
top to the bottom.
2. Fill the jug with water using a cup to measure amount of water it
takes to fill the jug. Mark each cup on on the tape (these
measurements will serve to show the amount of water exhaled) and screw
on the cap.
3. Fill the dish pan about 1/2 full with water.
4. Place the jug upside down in the water, and remove the cap.
5. Have a helper hold the jug. DO NOT allow air bubbles to enter the milk
6. Place one end of the aquarium tubing inside the mouth of the jug.
7. Take a normal breath and exhale through the tubing. Mark the water
level on the tape.
8. Refill the jug with water and return it to the dish pan.
9. Breath in deeply and make an effort to exhale all of the air in your
lungs through the tubing. Mark the water level on the tape.

Performance Assessment:

Students will be able to answer the following questions:
1. What are the chief functions of the respiratory system?
2. Why do we need to breathe?
3. What's in the air we breathe?
4. How do you know there is oxygen in the air we breathe?
5. What would happen if your oxygen ran out?
6. What do the small balloons represent?
7. What do the two ends of the straw to which the balloons are attached
8. What does the longer piece of straw represent?
9. What do the sides of the cup represent?
10. What does the balloon sheet over the cup's opening represent?
11. What happened to the small balloons when you pulled down on the balloon
12. What happened to the small balloons when you push up on the balloon
13. What happens to the air once it's in the lungs?
14. What is cellular metabolic activity?
15. What is the primary gaseous waste product of cellular metabolic
16. What's the stuff that comes out when you exhale?
17. What is lung capacity?
18. What happens in the plastic bottle as you exhale into the rubber tubing?
19. What effect does exercise have on the volume of air? Explain.


At the end of this lesson students will understand the basic anatomy and
physiology of the respiratory system.
Return to Biology Index