Worksheet: How Does the Heart Work?

Audience: Primary school, Age 9–11, mixed ability | Duration: 25 minutes | Format: Individual, in-class

Instructions

Start at Level 1. When you finish, move to Level 2. If you complete both, try Level 3. You do not have to finish all three — work at the pace that feels right. Write in full sentences where you can.

Level 1 — Getting Started

1. What does the heart do in your body?

2. Name two things blood carries around your body.

3. Where in your body is your heart located?

4. What happens to your heartbeat when you run or exercise?

Level 2 — Going Further

5. Explain why the body needs blood to keep moving. What would happen if it stopped?

6. The heart has four chambers. Why do you think it needs more than one section to do its job?

7. Your heart beats faster when you are scared, even if you are not moving. Why might that be?

8. How is the heart similar to a pump you might find in everyday life? How is it different?

Level 3 — Thinking Deeper

9. The left side and right side of the heart send blood to different places. What does this tell you about how the body manages different jobs at the same time?

10. A doctor says a patient’s heart is working harder than it should. Without knowing anything else, what are two possible reasons this might be happening?

11. If someone trained as an athlete for years, how might their heart be different from someone who rarely exercises? Explain your reasoning.

Answer Key

• 1. The heart pumps blood around the body.
• 2. Oxygen and nutrients — also accept carbon dioxide or waste products.
• 3. In the chest, slightly left of centre.
• 4. It beats faster to deliver more oxygen to working muscles.
• 5. Blood delivers oxygen and nutrients cells need to function. Without circulation, cells would quickly stop working and the body’s organs would fail.
• 6. Accept reasoning that identifies separation of oxygenated and deoxygenated blood as a more efficient system than mixing them.
• 7. The body prepares for action — fight or flight response — by increasing blood flow even before physical movement begins.
• 8. Similar: both move fluid using pressure and valves. Different: the heart is self-regulating, never switches off, and adjusts speed automatically.
• 9. Strong answers identify parallel processing — the body runs multiple circulatory loops simultaneously rather than sequentially.
• 10. Accept any two plausible reasons such as blocked arteries, high blood pressure, low fitness level, or the body fighting illness.
• 11. An athlete’s heart typically becomes larger and more efficient, pumping more blood per beat at a lower resting rate. Award reasoning that connects training adaptation to cardiac efficiency.

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