Science · 3rd Year · Human Life · Summer Term

The Breathing System

Investigate how your lungs work to take in oxygen from the air and release carbon dioxide, a process essential for life.

TL;DR:Let's explore the incredible, automatic system that works every second of every day: our breathing system! This topic gets pupils to investigate their own bodies to understand the amazing journey air takes to keep us alive and moving.

• NCCA Curriculum Specifications
• NCCA: Primary School Curriculum, Science - Strand: Living things - Strand unit: Human life (3rd/4th Class)

About This Topic

This topic on the Breathing System aligns directly with the 'Living Things' strand and the 'Human Life' strand unit of the SESE Science Curriculum for Third Class. It provides a foundational understanding of one of the body's most vital systems, moving beyond the simple fact that we need to breathe and delving into the mechanics and purpose of respiration. The investigation into how our lungs work, the process of gas exchange, and the impact of exercise and air quality on respiratory health are central to developing pupils' scientific literacy and promoting personal health and wellbeing. By engaging with this topic, pupils will develop skills in observing, predicting, and investigating, using simple models and their own bodies as primary sources of exploration. Contextualising this within the Irish environment can involve discussing the importance of our clean, green spaces for healthy air and the effects of local factors like traffic or peat fires on air quality, making the learning relevant and immediate.

Key Questions

1. Explain the journey of air from your nose to your lungs.
2. Analyse the effect of exercise on your breathing rate.
3. Justify the importance of clean air for healthy lungs.

Learning Objectives

• Describe the path air takes from the nose to the lungs.
• Identify the main parts of the breathing system, including the lungs, trachea, and diaphragm.
• Explain how and why our breathing rate changes during physical activity.
• Demonstrate the mechanics of breathing using a simple model.
• Justify the importance of clean air for maintaining healthy lungs.

Key Vocabulary

Lungs	The two main organs in your chest that take in oxygen from the air and pass it into your blood.
Trachea	The tube in your throat that carries air to your lungs, also known as the windpipe.
Diaphragm	A large, dome-shaped muscle at the bottom of the chest that helps you breathe in and out.
Oxygen	A gas in the air that our bodies need to get energy from food to live.
Carbon Dioxide	A waste gas that is made inside our bodies and is removed when we breathe out.

Watch Out for These Misconceptions

Common Misconception

We breathe in only oxygen and breathe out only carbon dioxide.

What to Teach Instead

We breathe in air, which is a mixture of many gases, including about 21% oxygen. The air we breathe out still contains a lot of the gases we breathed in, but with less oxygen and more carbon dioxide.

Common Misconception

The lungs are like empty bags that just fill up with air.

What to Teach Instead

The lungs are actually spongy and filled with millions of tiny, branching tubes and tiny air sacs called alveoli. This is where the important job of swapping oxygen for carbon dioxide happens.

Common Misconception

You don't breathe when you are asleep.

What to Teach Instead

Breathing is an automatic process that our body does all the time, even when we are sleeping. Our brain makes sure we keep breathing to stay alive.

Active Learning Ideas

Stations Rotation

Build a Lung in a Bottle

Pupils construct a simple model of a lung using a plastic bottle, a straw, and balloons. This hands-on activity demonstrates how the diaphragm muscle (represented by a balloon at the bottom) contracts and relaxes to inflate and deflate the lungs.

45 min·Pairs

Stations Rotation

Breathing Rate Investigation

Pupils work individually to count their number of breaths in one minute while resting. They then do one minute of star jumps or running on the spot and immediately count their breaths again, comparing the two figures to see the effect of exercise.

25 min·Individual

Stations Rotation

The Journey of Air

In small groups, pupils draw a large outline of a human torso on poster paper. They then draw and label the path air takes from the nose and mouth, down the trachea, and into the branching bronchi of the lungs.

30 min·Small Groups

Real-World Connections

• Understanding the health risks of smoking and vaping on the lungs.
• Learning basic first aid for someone who is choking.
• Recognising how asthma affects a person's breathing and how inhalers can help.
• Appreciating the role of trees and plants in our environment for producing the oxygen we need.
• Discussing the impact of air pollution from cars and factories on our respiratory health.

Assessment Ideas

Discussion Prompt

Use a 'think-pair-share' activity where pupils first think about how exercise affects breathing, then discuss with a partner, and finally share with the class. Listen to their reasoning to gauge understanding.

Peer Assessment

Pupils create a short comic strip or a series of drawings that illustrates the journey of a breath of air through the respiratory system, labelling the key parts.

Quick Check

Pupils use a 'traffic light' system (red, orange, green dots) to indicate their confidence in explaining the function of the lungs, trachea, and diaphragm.

Frequently Asked Questions

Why do I get a stitch in my side when I run?

A stitch is usually a cramp in your diaphragm, the big muscle under your lungs that helps you breathe. It can happen when you're not used to exercising or if you breathe in a shallow way while running.

What makes us yawn?

Scientists are still exploring why we yawn, but one popular idea is that it helps to cool down our brain. Another is that it's a way to take in a big gulp of oxygen when our breathing has become too slow or shallow.

Why is it better to breathe through your nose than your mouth?

Your nose is brilliant at cleaning, warming, and moistening the air before it gets to your lungs. The tiny hairs and mucus in your nose trap dust and germs, protecting your lungs.