Life Science- The Function of the Lungs

Focus Question:

• What happens to our lungs as we breathe in and out?

The teacher will ask students the following questions: Can anyone tell me what it means to inhale? (Breathe in) Can anyone tell me what it means to exhale? (Breathe out) Does anybody know what the diaphragm is used for in the body? (Diaphragm: the diaphragm separates the thoracic cavity containing the heart and lungs, from the abdominal cavity and performs an important function in respiration: as the diaphragm contracts, the volume of the thoracic cavity increases and air is drawn into the lungs.) The teacher will refer to the picture of the labeled body that is displayed on the projector.

Now that we know what these terms mean, does anybody know what makes inhaling and exhaling happen?

The teacher will encourage students to stand up and fill their rib cage. Students will breathe in and out. What do you notice happen when you are breathing? What do you notice happen as you inhale? What do you notice when you happen as you exhale? The teacher will give students the opportunity to discuss their answers and observations from the activity.

Prediction Statement:

• If we squeeze the water bottle (diaphragm), then we will observe the blue balloon (lung) filling with air.

When you breathe in, the diaphragm contracts (pull the diaphragm balloon down). This lowers the air pressure in the chest cavity (because there’s more room) and air fills the lungs. The teacher will have students turn and talk about what they predict will happen during the investigation regarding the water bottle and balloons. The teacher will then fill in the prediction column of the data chart with student responses.

Planning

Materials:

• Water bottles
• Blue balloons
• Red balloons

Procedure:

• Students will be placed into groups of 4; each group will have one water bottle and two balloons. They will follow the steps listed below.

Steps:

• Start with a water bottle
• Cut the bottom off of the water bottle (you may need to place tape on the edges for students so no one gets cut)
• Place the blue balloon inside the neck of the water bottle and stretch the opening to the balloon over the neck of the water bottle
• Cut the top/narrow half off on the red balloon
• Stretch the remaining half of the balloon over the bottom of the water bottle

Data

Data Chart: Testing the Balloon

Predictions	What did we learn?
- Fill blue balloon with air, red balloon pushes out. -Squeeze bottle, blue balloon fills with air red balloon contracts.	- Squeezing the bottle deflates the blue balloon. -The faster you inhale, the less air you get to your lungs. -  The slower you inhale the more air you get to your lungs.

Claims and Evidence:

Based on our observations during the investigation what have you learned about the lung?

• When we squeeze the water bottle (diaphragm), the blue balloon fills with air.
• When we release the water bottle, air is released from the blue balloon.

Conclusion/Questions:

• In this investigation we learned that when we exhale, the diaphragm relaxes and air flows out of the lungs and when we inhale, the diaphragm contracts and air fills the lungs.
• What do you think would happen if we only had one balloon?
• What do you think would happen if we didn’t cut the bottom of the bottle off?
• Do you think that different factors would affect the functions of the water bottles/balloons.
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