The Respiratory System: Breathing In and Out

Active learning lets students feel and see the mechanics of breathing, turning abstract processes into tactile experiences. When they build a model or measure their own breathing rates, the respiratory system moves from a diagram to a lived phenomenon.

• Year 6
• Science
• 4 activities
• 25 min–45 min

Learning Objectives

1. Explain the mechanical actions of the diaphragm and intercostal muscles during inhalation and exhalation.
2. Analyze the diffusion of oxygen and carbon dioxide across the alveolar and capillary membranes.
3. Compare the effects of different levels of physical activity on breathing rate.
4. Predict how inhaled pollutants might affect the efficiency of gas exchange in the lungs.

Experiential Learning

⏱ 30 min·Small Groups

Model Building: Balloon Lung Demo

Provide plastic bottles, balloons, and straws for students to assemble a lung model. One balloon acts as the diaphragm, another pair as lungs; pulling the diaphragm balloon expands the lung balloons to simulate inhalation. Groups test and record how volume changes affect air flow.

Prepare & details

Explain how air enters and leaves the lungs during breathing.

Facilitation Tip: During the Balloon Lung Demo, circulate to ensure students attach the balloon correctly to the bottle base so the diaphragm simulation works smoothly.

Setup: Varies; may include outdoor space, lab, or community setting

Materials: Experience setup materials, Reflection journal with prompts, Observation worksheet, Connection-to-content framework

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

Experiential Learning

⏱ 25 min·Pairs

Experiment: Exercise Breathing Rates

Students measure resting breathing rate for one minute using a stopwatch. Pairs then jog in place for two minutes and remeasure, graphing results to compare changes. Discuss why rates increase and link to oxygen needs.

Prepare & details

Analyze the process of oxygen and carbon dioxide exchange in the alveoli.

Facilitation Tip: For the Exercise Breathing Rates experiment, set clear timing for each student’s run, and have timers ready to maintain consistency.

Setup: Varies; may include outdoor space, lab, or community setting

Materials: Experience setup materials, Reflection journal with prompts, Observation worksheet, Connection-to-content framework

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

Stations Rotation

⏱ 45 min·Small Groups

Stations Rotation: Gas Exchange Stations

Set up stations: one with bubble solution to model alveoli diffusion, another with tea bags in water for gas exchange analogy, a third for pollution filters using tissue paper, and a discussion station. Groups rotate, noting observations.

Prepare & details

Predict the impact of air pollution on respiratory health.

Facilitation Tip: At Gas Exchange Stations, assign small groups to rotate every three minutes so they experience each station fully without crowding.

Setup: Tables/desks arranged in 4-6 distinct stations around room

Materials: Station instruction cards, Different materials per station, Rotation timer

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Experiential Learning

⏱ 35 min·Whole Class

Prediction Challenge: Pollution Impact

Show images of polluted vs clean air; students predict effects on lungs using drawings. Test with simple filters on straws blowing into water, observing particle capture, then revise predictions.

Prepare & details

Explain how air enters and leaves the lungs during breathing.

Facilitation Tip: In the Pollution Impact Prediction Challenge, provide images of polluted and clean air to ground student predictions in reality.

Setup: Varies; may include outdoor space, lab, or community setting

Materials: Experience setup materials, Reflection journal with prompts, Observation worksheet, Connection-to-content framework

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

Teaching This Topic

Use modeling to confront misconceptions early, especially about the diaphragm and constant air exchange. Research shows that students often visualize lungs as static containers, so physical models that show air flowing in and out correct this error faster than diagrams alone. Also, connect the mechanics to function by having students repeatedly link muscle contractions to gas movement before discussing diffusion.

What to Expect

Students will explain how air moves in and out of the lungs by linking diaphragm movement to pressure changes. They will also trace oxygen and carbon dioxide diffusion at the alveoli and connect exercise to increased breathing rates.

Watch Out for These Misconceptions

Common Misconception

During the Balloon Lung Demo, watch for students who describe the balloon filling up and staying full.

What to Teach Instead

Have students repeatedly inflate and deflate the balloon while saying ‘air flows in’ and ‘air flows out’ to emphasize constant exchange, not storage.

Common Misconception

During the Exercise Breathing Rates experiment, watch for students who believe oxygen is used up completely in the body.

What to Teach Instead

Ask students to connect their rapid breathing after exercise to the need to restore oxygen supply, not to ‘use up’ oxygen permanently.

Common Misconception

During the Balloon Lung Demo with diaphragm palpation, watch for students who say breathing happens only in the chest.

What to Teach Instead

Guide students to place one hand on their belly to feel the diaphragm’s downward movement during inhalation, linking the internal muscle to the external model.

Assessment Ideas

Exit Ticket

After the Balloon Lung Demo, give each student a card with a lung diagram and ask them to label the trachea, diaphragm, and alveoli, then write one sentence about diaphragm movement during inhalation.

Quick Check

During the Exercise Breathing Rates experiment, ask students to compare their breathing rates while standing versus sitting and explain why standing increased their rate, listening for references to muscle activity and oxygen demand.

Discussion Prompt

After the Pollution Impact Prediction Challenge, facilitate a class discussion where students explain to a ‘patient’ how smog affects lung function, assessing their ability to connect particle size to alveoli damage and coughing.

Extensions & Scaffolding

• Challenge early finishers to research asthma and present a 90-second explanation of how it affects lung function using the model they built.
• Scaffolding: Provide a sentence stem for students who struggle during the balloon demo: 'When the balloon _____, the space inside _____, so air _____.'
• Deeper exploration: Ask students to graph breathing rates before and after exercise, then compare their class graphs to published data on athlete breathing rates.

Key Vocabulary

Diaphragm	A large, dome-shaped muscle located at the base of the chest cavity that helps with breathing. When it contracts, it flattens and moves downward, increasing chest volume.
Alveoli	Tiny, air-filled sacs in the lungs where the exchange of oxygen and carbon dioxide takes place between the air and the blood.
Diffusion	The movement of particles from an area of higher concentration to an area of lower concentration. This process is how gases move between the alveoli and the blood.
Trachea	The windpipe, a tube that connects the larynx (voice box) to the bronchi of the lungs, allowing the passage of air.
Haemoglobin	A protein found in red blood cells that carries oxygen from the lungs to the body's tissues and returns carbon dioxide from the tissues to the lungs.