PROJECT

Model-Making Lab DATASHEET FOR LABBOOK
Build a Lung
When you breathe, you actually pull air into your lungs because your diaphragm muscle causes your chest to expand. You can see this is true by placing your hands on your ribs and inhaling slowly. Did you feel your chest expand? In this activity, you will build a model of a lung by using some common materials. You will see how the diaphragm muscle works to inflate your lungs. Refer to the diagrams in the textbook as you construct your model.

MATERIALS
• bag, trash, small plastic
• balloon, small
• bottle, top half, 2 L
• clay, golf-ball-sized piece

PROCEDURE
1. Attach the balloon to the end of the straw with a rubber band. Make a hole through the clay, and insert the other end of the straw through the hole. Be sure at least 8 cm of the straw extends beyond the clay. Squeeze the ball of clay gently to seal the clay around the straw.
2. Insert the balloon end of the straw into the neck of the bottle. Use the ball of clay to seal the straw and balloon into the bottle.
3. Turn the bottle gently on its side. Place the trash bag over the cut end of the bottle. Expand a rubber band around the bottom of the bottle to secure the bag. You may wish to reinforce the seal with tape. Before the plastic is completely sealed, gather the excess material of the bag into your hand, and press toward the inside of the bottle slightly. (You may need to tie a knot about halfway up from the bottom of the bag to take up excess material.) Use tape to finish sealing the bag to the bottle with the bag in this position. The excess air will be pushed out of the bottle.

ANALYZE THE RESULTS
1. What can you do with your model to make the “lung” inflate?
2. What do the balloon, the plastic wrap, and the straw represent in your model?
3. Using your model, demonstrate to the class how air enters the lung and how air exits the lung.

APPLYING YOUR DATA
Do some research to find out what an “iron lung” is and why it was used in the past. Research and write a report about what is used today to help people who have difficulty breathing.

PROJECT

MODEL-MAKING
Performance-Based Assessment
OBJECTIVE
You’ve read about circulation and respiration in the human body. Now you will have a chance to model the blood flow in the human heart! In this activity you will use the materials provided to build a model of the heart and lungs and to illustrate blood flow.

KNOW THE SCORE!
As you work through the activity, keep in mind that you will be earning a grade for the following:
• how well you work with the materials (30%)
• how well you know the correct structure of the heart and lungs and can illustrate the blood flow between chambers (40%)
• how well you complete the analysis (30%)

MATERIALS AND EQUIPMENT
• cardboard tubes, 2
• egg carton
• glue

SAFETY INFORMATION
• Use scissors safely.
• Pipe cleaners can have sharp ends.

PROCEDURE
1. Cut the egg carton apart so that you have 8 “cups.” Glue pairs of them together facing each other so that you have four chambers. Label two of the chambers “atrium” and two of the chambers “ventricle.” Label the atria “left” and “right.” Label the ventricles “left” and “right.”
2. Secure the chambers together with the pipe cleaners. Use red pipe cleaners to represent oxygen-rich blood and blue pipe cleaners to represent oxygen-poor blood. Show the blood flow into each atrium, between the atria and the ventricles, and out of each ventricle. Attach the atria and ventricles together with the white pipe cleaners.
3. What are blood vessels that carry blood away from the heart called?
4. What are blood vessels that carry blood toward the heart called?
5. Use the cardboard tubes to represent lungs. Connect them to the heart, again with the red and blue pipe cleaners in the correct places to represent blood vessels carrying oxygen-rich and oxygen-poor blood. Do arteries always carry oxygen-rich blood? Explain.


ANALYSIS
To answer the following questions, position your model so that it has the same orientation as the heart in your body.
6. Which side of the heart has oxygen-poor blood flowing through it?
7. Which side of the heart has oxygen-rich blood flowing through it?
8. Describe the pathway of blood going to and coming from the lungs.
9. Which of the chambers has the strongest pumping action, and why is this necessary?