Brush Up on Breathing

Squishy, slimy and SPONGY, our lungs help us breathe!

We need oxygen for our bodies to function, and the lungs help us get the air we need! Lungs are pink and spongy and fill up with air when we breathe in, or inhale.

In this activity, you will use sponges to paint the texture of lungs.


  • The lungs are a part of the respiratory system, which helps bring oxygen from the air into the body.
  • Oxygen reacts with the sugar we get from food, creating energy that powers the body.
  • Air flows in through the nose or mouth, down the windpipe (called the trachea) and into the lungs.
  • A sponge has lots of holes and air in it – and our lungs do, too! They are pink and spongy
  • In the lungs there are bronchial tubes, which turn into bronchi/bronchioles as they get smaller. These root-like tubes are 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.
  • When we inhale, the lungs expand. Exhale, deflate.
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


  • Sponges
  • Red paint or red ink pad (washable)
  • Smocks or aprons to cover clothing
  • Disposable tablecloth or newspaper to cover work surface
  • Outline of the lung (download below)
Start a conversation!

Activity Plan

  1. [optional] There are millions of tiny tunnels (bronchial tubes) in the lungs that help transport the oxygen throughout the lungs. Using a marker, draw the tubes onto the lungs

2. Dip a sponge into the paint or ink pad and gently dab it onto the paper with the lungs

3. Notice how the texture left by the sponge mimics the texture of lungs

As with all activities, adult supervision may be required.

Follow-Up Questions

  • What part of the respiratory system is this?
  • What is missing from this model? What could we add?

Extension Activities

To represent the ends of the bronchi (the root-like tubes in the lungs), students can use fingerprints to show the tiny air sacs (alveoli).

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.