how lungs work

How Lungs Work: A Health Science Experiment

World Health Day falls annually in April to spark awareness for the World Health Organization (WHO). WHO is the authority for health in United Nations system and is responsible for providing leadership on global health matters. This experiment can forward WHO’s efforts by helping kids appreciate healthy lung function…as well as learn a couple things about how our faith lives and breathes.


• Empty 20 ounce plastic water bottle

• Scissors

• Two balloons

• Straw

• Clay or Play Dough

• Knife to cut plastic bottle

• Tape


Genesis 2:7 states, “And the Lord God formed a man from the dust of the ground, and breathed into his nostrils the breath of life, and the man became a living soul.” Since that time, man has taken about 17,000 breaths each day, and every time we breathe, our lungs fill with oxygen and get rid of unwanted carbon dioxide. Let’s take a look at this process that God designed with some very cool wisdom about what man would need to stay alive…



1. Cut off the bottom of a 20 ounce plastic bottle. (Older students can do this.)

2. Snip the neck from a large balloon, and then stretch the balloon onto the cut off bottom of the bottle. Use tape to secure the balloon to the bottle.

3. Snip the neck from another balloon.

4. Stick a straw into that balloon and tape it in place.

5. Now slide the balloon with the straw into the bottle, leaving about three inches of the straw

outside the bottle.

6. Be sure no air gets into the bottle. To do that, use clay or Play Dough to seal the bottle and to hold the straw in place.

7. The balloon inside of the bottle represents the lung. To make it work, gently pull down, and

then push in on the outer balloon. The inner balloon will inflate and deflate.


The bottle represents the chest. The inner balloon represents the diaphragm (the muscle that helps you breathe.) When the diaphragm stretches (that happens when the outside balloon pulls downward) the chest cavity expands and the lungs take in air. When the diaphragm relaxes, the space in the chest cavity shrinks causing the lungs to expand.

In simple terms, respiration begins in the nose which works as a kind of vacuum cleaner to trap pollutants. From there the air passes into the main windpipe for more cleaning, and finally into the lungs where cells continue the clean-up work.


The World Health Organization is teaching people around the world about healthy lungs. But healthy lungs are a little like our Christian lives. When we fill ourselves with the Holy Spirit, we don’t have room for some of the wrong things we do or would like to do. Let’s say we’ve been mean to a younger sister or brother. The filling of the Holy Spirit makes us want to let go of that meanness.

We have to “breathe in” the Holy Spirit and “breathe out” sinful desires each and every day!

*Image Source:



About Mary Kate Warner

Mary-Kate is a regular blogger at Christianity Cove (  You can often find her writing about Christian Parenting, Homeschool Teaching, Bible Study and Sunday School Activities, Faith and inspiring children to love God.  Follow her at @SundaySchoolGal, Facebook Pinterest

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