An Air Affair

Take a deep breath and feel your chest getting bigger – what is happening?

We need oxygen for our bodies to function, and the lungs help us get the air we need! Take a deep breath and feel your chest expand – those are your lungs inflating. Exhale and feel them deflate!

In this activity, you will create a model of the lungs that show what happens when you breathe!

-Identify and locate the lungs in the human body
-Explain that lungs expand and contract when you inhale and exhale

Key Vocabulary:
Breathing, Contract, Exhale, Expand, Inhale, Lung, Respiratory System


  • The lungs are a part of the respiratory system, which helps bring oxygen from the air into the body.
  • Air flows in through the nose or mouth, down the windpipe (called the trachea) and into the brionchial tubes, root-like tubes/small tunnels that help the air flow through the lungs
  • At the end of the bronchi are alveoli, which are tiny air pockets. The alveoli help the oxygen get into red blood cells. There are hundreds of millions of alveoli in the lungs.
  • Our lungs take a gas called oxygen out of the air and replace it with a gas called carbon dioxide. The carbon dioxide is passed back out through the bronchi, into the trachea, and out of the mouth or nose.
  • Blood passes through the lungs and picks up the oxygen. The blood carries the oxygen to cells throughout the body, because it reacts with the sugar we get from food, creating energy that powers the body.
  • When we inhale, the lungs infalte. Exhale, deflate.
  • When we exercise, we use more oxygen and our breathing quickens.
  • When we sleep, we use less oxygen and our breathing slows down.
The Respiratory System

Check it out!

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“See” the inside of the body with this super fun book by Carron Brown and Rachael Saunders


  • 1-2 plastic straws
  • 1-2 small plastic sandwich bags (fold top, not Ziplock)
  • Colorful masking tape or clear tape
  • Sharpies

Key Questions

Start a conversation!

Activity Plan

  1. There are millions of tiny tunnels (bronchial tubes) in the lungs that help transport the oxygen throughout the lungs. Using a Sharpie, trace or draw a representation of the tubes onto the plastic baggie.

2. Place a straw inside the bag…

…and twist the top of the bag tightly around the straw.

3. Secure the twist with tape, ensuring there is a tight seal. You may need two pieces of tape to get all of the holes sealed up.

[optional] Repeat with the other straw and bag and tape the two together, representing both lungs.
4. Gently blow into the straws and watch your plastic bag lungs inflate.

Testing our lung models! Watch them inflate!

As with all activities, adult supervision may be required as small children should not play with plastic baggies.

Follow-Up Questions

  • What happens when you blow into the straws?
  • What part of the respiratory system do the straws represent? The bags?
  • What is missing from this model? What could we add?

Extension Activities

  • Using large straws, put some slime in one and leave one clear. Have one child use the slime straw and one child use the clear straw to have pinwheel races, blow boats across water, etc. to show that the blocked straw (or the asthmatic lung) is harder to get air through.

NGSS Connections (Life Science)

Disciplinary Core IdeaConnect It!
LS1.A: Structure and Function All organisms have external parts. Different animals use their body parts in different ways to see, hear, grasp objects, protect themselves, move from place to place, and seek, find, and take in food, water and air. Plants also have different parts (roots, stems, leaves, flowers, fruits) that help them survive and grow. (1-LS1-1) Humans use lungs to take in air. How are our lungs similar or different to other organisms’ lungs? How do plants take in air?
LS1.A: Structure and Function Plants and animals have both internal and external structures that serve various functions in growth, survival, behavior, and reproduction. (4-LS1-1)
LS4.D: Biodiversity and Humans Populations live in a variety of habitats, and change in those habitats affects the organisms living there. (3-LS4-4) Look at asthma rates in different areas. Why do some communities/places have higher rates of asthma than other places? How is the environment affecting how people can breathe? More background on this topic.
LS2.B: Cycles of Matter and Energy Transfer in Ecosystems Matter cycles between the air and soil and among plants, animals, and microbes as these organisms live and die. Organisms obtain gases, and water, from the environment, and release waste matter (gas, liquid, or solid) back into the environment. (5-LS2-1) Compare and contrast how plants and animals breathe.