the cardio-respiratory system
4 detailed 50-minute lessons with teaching scripts, worked examples, parent guides, and assessment criteria.
Lesson Overview
Total Lessons: 4
Tier: Foundation and Higher
Duration: 50 minutes per lesson (200 minutes total)
Exam Boards: AQA, Edexcel, OCR, Eduqas, CCEA
Tier: Foundation and Higher
Duration: 50 minutes per lesson (200 minutes total)
Exam Boards: AQA, Edexcel, OCR, Eduqas, CCEA
Learning Objectives
- Explain the key ideas of the cardio-respiratory system
- Apply the cardio-respiratory system to exam-style questions
- Develop independent study skills
- Build cross-topic connections
Prerequisites
- Read the revision notes for the cardio-respiratory system first (GCSE Revise summary)
- Key vocab to pre-teach: Key Sequence, The heart, Key Concept
- Basic skills: reading the summary notes and answering the practice questions there
Materials & Equipment
- Exercise book, coloured pens
- Ruler
- Printed revision notes (link below)
- Internet for videos (see Resources)
Lesson 1: Introduction: the cardio-respiratory system
Duration: 50 minutes
Starter Activity (5 minutes)
Quick Recall
Write down everything you already know about the cardio-respiratory system. Then check against the key terms: Key Sequence, The heart, Key Concept. Use a mini-whiteboard or paper.
Main Content (35 minutes)
Parent/Teacher Guide:
Before lesson: Read the script below. Pre-teach key vocab: Key Sequence, The heart, Key Concept.
If stuck: Re-read the revision notes (link above), then break the content into smaller steps.
Extension: See the Stretch & Challenge ideas in Lesson 4.
Before lesson: Read the script below. Pre-teach key vocab: Key Sequence, The heart, Key Concept.
If stuck: Re-read the revision notes (link above), then break the content into smaller steps.
Extension: See the Stretch & Challenge ideas in Lesson 4.
Teaching Script (35 mins):
Mins 0-5 - Hook: "Today: the cardio-respiratory system. By the end you will be able to answer exam questions on it unaided. It connects to the rest of Physical Education because the ideas here recur across the spec."
Mins 5-20 - Direct Instruction: Work through the core ideas below one at a time; after each, ask your student to explain it back in their own words.
Mins 20-30 - Guided Practice: Model the worked example together, then let your student attempt the first practice question with guidance.
Mins 30-35 - Independent Practice: 2-3 practice questions from Lesson 3 below, with immediate feedback.
Mins 0-5 - Hook: "Today: the cardio-respiratory system. By the end you will be able to answer exam questions on it unaided. It connects to the rest of Physical Education because the ideas here recur across the spec."
Mins 5-20 - Direct Instruction: Work through the core ideas below one at a time; after each, ask your student to explain it back in their own words.
Mins 20-30 - Guided Practice: Model the worked example together, then let your student attempt the first practice question with guidance.
Mins 30-35 - Independent Practice: 2-3 practice questions from Lesson 3 below, with immediate feedback.
First Look
Start with the revision notes summary, then attempt: Describe the pathway of air from the nose to the alveoli.
Plenary (5 minutes)
Check Out
Your student states one thing they learned and one question they still have about the cardio-respiratory system.
Lesson 2: Core Concepts: the cardio-respiratory system
Duration: 50 minutes
Starter Activity (5 minutes)
Review Previous Lesson
Quick recap: write 3 key points from Lesson 1 on the cardio-respiratory system. Check them against the notes below.
Main Content (35 minutes)
Key Sequence: Air travels through the respiratory system in this exact order: Nose → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Alveoli
Definition: Gaseous exchange is the diffusion of gases between the alveoli and the blood in the surrounding capillaries. Oxygen moves from the alveoli into the blood, and carbon dioxide moves from the blood into the alveoli.
Features that make alveoli efficient for gaseous exchange: Large surface area - approximately 70m² (roughly the size of a tennis court) Thin walls - alveoli and capillary walls are each one cell thick, creating a very short diffusion distance Moist lining - gases dissolve in the moisture before diffusing Dense capillary network - ensures constant blood flow for efficient exchange Good ventilation - constant supply of fresh air maintains the concentration gradient
The heart: is a muscular pump with four chambers : two atria (upper, receiving chambers) and two ventricles (lower, pumping chambers). It is divided into a right side (pumping deoxygenated blood to the lungs) and a left side (pumping oxygenated blood to the body).
Why the left ventricle has the thickest wall: The left ventricle must pump blood to the entire body (systemic circulation), requiring much higher pressure than the right ventricle, which only pumps blood to the nearby lungs (pulmonary circulation).
Key Concept: Humans have a double circulatory system - blood passes through the heart twice for each complete circuit of the body. This allows blood to be pumped at a much higher pressure, delivering oxygen more efficiently.
| Term | Meaning | Example |
|---|---|---|
| Nose | Two nasal passages with hairs and mucous membrane | Filters dust and bacteria; warms and moistens the air |
| Pharynx (throat) | Muscular tube shared with digestive system | Passageway for air to the larynx |
| Larynx (voice box) | Contains vocal cords; epiglottis on top | Epiglottis prevents food entering the trachea; produces sound |
| Trachea (windpipe) | Tube with C-shaped cartilage rings; lined with cilia and mucus | Carries air to the bronchi; cartilage prevents collapse; cilia move mucus and trapped particles upward |
| Bronchi | Two branches (left and right) from the trachea | Carry air into each lung; also lined with cartilage and cilia |
| Bronchioles | Smaller branches within each lung | Distribute air throughout the lungs; smooth muscle controls diameter |
| Alveoli | Tiny air sacs at the end of bronchioles; surrounded by capillaries | Site of gaseous exchange between air and blood |
| Right atrium | Receives deoxygenated blood from the body via the vena cava | Deoxygenated |
Practice (10 minutes)
Q: Describe the pathway of air from the nose to the alveoli.
Answer: Nose → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Alveoli. Each structure filters, warms or channels the air towards the alveoli where gaseous exchange occurs.
Plenary (5 minutes)
Explain Back
Your student teaches the key points back to you without looking. Fill any gaps immediately.
Lesson 3: Application: the cardio-respiratory system
Duration: 50 minutes
Starter Activity (5 minutes)
Quick Recall
Recall the key terms: Key Sequence, The heart, Key Concept. Define each in one sentence.
Main Content (35 minutes)
Parent/Teacher Guide: Let your student attempt each question alone first, then compare with the model answer. Award method marks for correct working even if the final answer is wrong.
Q1: Describe the pathway of air from the nose to the alveoli.
Answer: Nose → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Alveoli. Each structure filters, warms or channels the air towards the alveoli where gaseous exchange occurs.
Q2: Explain three features of alveoli that make them efficient for gaseous exchange.
Answer: Large surface area (approximately 70m²) allows a high rate of diffusion. Thin walls (one cell thick for both alveoli and capillaries) create a short diffusion distance. Moist lining allows gases to dissolve before diffusing. Dense capillary network maintains the concentration gradient with constant blood flow.
Q3: Why does the left ventricle have a thicker muscular wall than the right ventricle?
Answer: The left ventricle pumps blood through the aorta to the entire body (systemic circulation), requiring high pressure. The right ventricle only pumps blood to the nearby lungs (pulmonary circulation), which requires much lower pressure.
Q4: Describe the difference between pulmonary circulation and systemic circulation.
Answer: Pulmonary circulation carries deoxygenated blood from the right ventricle to the lungs via the pulmonary artery, and returns oxygenated blood to the left atrium via the pulmonary vein. Systemic circulation carries oxygenated blood from the left ventricle to the body via the aorta, and returns deoxygenated blood to the right atrium via the vena cava.
Q5: Compare the structure of arteries, veins and capillaries.
Answer: Arteries have thick walls (muscle and elastic tissue), small lumens and high pressure, with no valves. Veins have thinner walls, larger lumens and lower pressure, with valves to prevent backflow. Capillaries are one cell thick with very small lumens, allowing exchange of materials with tissues.
Q6: Why do veins contain valves but arteries do not?
Answer: Veins carry blood at low pressure back to the heart. Without valves, gravity and low pressure would cause blood to pool or flow backwards, especially in the legs. Arteries carry blood at high pressure, generated by the heart, so the pressure itself prevents backflow and valves are unnecessary.
Plenary (5 minutes)
Error Review
Review any questions answered incorrectly. Identify whether the error was knowledge, method, or reading the question.
Lesson 4: Exam Practice: the cardio-respiratory system
Duration: 50 minutes
Starter Activity (5 minutes)
Command Words
Review what these command words require: state (one point), describe (say what happens), explain (say why), compare (both sides), evaluate (judgement).
Main Content (35 minutes)
Exam-Style Question
Attempt a past-paper style question on the cardio-respiratory system from the exam board past paper finder (see Resources), then mark it against the scheme.
Exam Tips: Use the exact pathway sequence - missing a step loses marks | Remember: pulmonary artery = deoxygenated, pulmonary vein = oxygenated (the exceptions) | When describing gaseous exchange, always mention diffusion and the concentration gradient | Know the four chambers of the heart and whether they carry oxygenated or deoxygenated blood | Be prepared to explain why the left ventricle has the thickest wall | Capillaries being "one cell thick" is a key phrase examiners look for
Common Errors: Watch Out! Students often say all arteries carry oxygenated blood. Wrong: "Arteries always carry oxygenated blood." Correct: "Arteries carry blood away from the heart. The pulmonary artery carries deoxygenated blood." Students often confuse the bicuspid and tricuspid valve positions. Wrong: "The tricuspid valve is on the left side." Correct: "The tricuspid valve is between the right atrium and right ventricle."
Stretch & Challenge (Grade 8-9):
- Synoptic links: explain how the cardio-respiratory system connects to another Physical Education topic you have studied
- Real-world: research one real-world use or example of the cardio-respiratory system
- Critical: "What are the limitations of the models used in the cardio-respiratory system?"
Plenary (5 minutes)
Assessment Criteria
- Got it: Confident explanation + correct worked examples
- Getting there: Main points OK, needs support with detail
- Not yet: Confused on key concepts - re-run Lesson 2
Homework & Consolidation
- Consolidation: Re-answer any Lesson 3 practice questions answered incorrectly (20 mins)
- Retrieval: Write flashcards for the key terms: Key Sequence, The heart, Key Concept (10 mins)
- Exam practice: One past-paper question on the cardio-respiratory system from the board websites (15 mins)
- Extension: Explain the cardio-respiratory system to someone else in your own words (10 mins)