Breathing Pathways

Overview

This lesson builds on earlier learning about how the body systems work together. Students will investigate how the respiratory system supports breathing and how oxygen is transported to the body by the circulatory system, using a simple breathing simulation to model the process.

Learning intentions

• Students will identify the main parts of the human respiratory system and describe their roles in breathing.
• Students will explain the sequence of what happens when we breathe in and breathe out.
• Students will link respiration to the circulatory system by describing how oxygen gets to the body.
• Students will use scientific enquiry skills to make observations and draw conclusions from a model.

Success criteria

• I can name key parts of the respiratory system (e.g. lungs, trachea/windpipe, diaphragm).
• I can describe how breathing brings oxygen into the body and helps remove carbon dioxide.
• I can explain, in simple terms, how oxygen travels to body cells through the circulatory system.
• I can use evidence from our breathing simulation to support a claim about how breathing works.

Curriculum links

• Animals including humans: main parts of the human circulatory system and functions of the heart, blood vessels and blood (linking oxygen delivery to the body).
• Notes and guidance (animals including humans): exploring the relationship between diet, exercise, drugs, lifestyle and health (context for why breathing matters).
• Working scientifically: talk about what happens and make predictions when investigating a model of breathing.

Lesson structure (45 minutes)

1. 0–5 min · Starter: “What changes?”

• Teacher shows a diagram of lungs and asks: “When we breathe in, what goes into the body? When we breathe out, what comes out?”
• Students do a quick think-write, then share answers in pairs, using sentence stems: “When I breathe in, I think… because…”

2. 5–15 min · Direct teach: Respiratory roles

• Teacher uses a simple labelled model (board diagram) to explain: air enters via nose/mouth, travels down the windpipe (trachea), into lungs, and the diaphragm helps change lung volume.
• Students complete a short guided note-catcher: “Breathing in: ___ happens; Breathing out: ___ happens; Parts: ___”.

3. 15–23 min · Guided discussion: breathing to circulation link

• Teacher connects systems: oxygen from inhaled air moves into blood in the lungs; blood carries oxygen to body cells; carbon dioxide is removed when breathing out.
• Students sort statements into two columns: “Respiratory system mainly does” / “Circulatory system mainly does”, then justify one choice to a partner.

4. 23–35 min · Hands-on: Breathing simulation

• Teacher demonstrates the materials and models “breathing” using lung volume—e.g. a clear bottle as a chest, balloons as lungs, tubing as the airway, and a flexible membrane/balloon as the diaphragm driver.
• Students work in groups to run the simulation: they record what happens to the “lungs” (balloon size) when they “inhale” and “exhale”, and note where “air” goes in their model using a simple labelled sketch.

5. 35–40 min · Talk moves: Predictions and evidence

• Teacher prompts: “If we pull the diaphragm more strongly, what do you predict happens to the lungs/breathing?” and “What evidence do we have from the model?”
• Students make one prediction and then confirm/adjust their thinking after trying one additional simulation variation (e.g. faster pull vs slower pull).

6. 40–45 min · Exit ticket: Explain the process

• Teacher asks students to complete a 3-part exit question: (1) name two respiratory parts and what they do, (2) describe what breathing in/out changes, (3) explain how this links to the circulatory system using the word oxygen.
• Students submit answers independently; teacher checks quickly for misconceptions.

Resources

• Labelled respiratory system diagram for teacher and students
• Breathing simulation kits (per group): clear bottle or similar container, 2 balloons (lungs), tubing or straws (airway), flexible balloon or sheet/elastic (diaphragm driver), sticky tape, scissors (teacher-managed), marker pens
• Note-catcher sheet (breathing in/out, key parts, sequence)
• Statement cards for sorting (respiratory vs circulatory)
• Sketch paper for model diagram
• Exit ticket slips or digital form
• Safety equipment: eye protection (recommended), clear expectations for scissors/glass (if any)

Assessment

• Teacher formative assessment during starter discussion using sentence stems and misconceptions to correct immediately.
• Observation during model work: listen for accurate descriptions of air movement and lung volume changes.
• Exit ticket responses: check that students include oxygen and correctly link breathing to the circulatory system (blood carries oxygen; carbon dioxide leaves via breathing out).

Differentiation

• Support: provide sentence starters (“Breathing in brings…”, “The diaphragm…”, “Oxygen moves into the…”) and a word bank (lungs, windpipe, diaphragm, oxygen, carbon dioxide, blood).
• Support: offer partially labelled diagrams so students can concentrate on explanation rather than drawing.
• Extension: challenge students to explain why rapid breathing after exercise can change how quickly oxygen and carbon dioxide are exchanged (link to lifestyle/health context).
• EAL/SEN: allow verbal recording of exit ticket for some students; use visual sorting cards with clear icons and limit to fewer statements for those needing a shorter task.
• Practical: assign roles within groups (materials manager, recorder, explainer) to ensure every student participates.

Notes for the teacher (unit flow)

• Emphasise the “systems connection” each time: respiratory brings gases in/out; circulatory transports oxygen to the rest of the body so cells can release energy.