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Science

The Circulatory System

Overview

Students trace the journey of blood around the body, discovering the double circulation system and the role of each component.

Learning Objective
Students understand how the heart, blood vessels, and blood work together to transport substances around the body.

Resources needed

  • None — or a simple diagram drawn on paper or ground

Lesson stages

0 / 7 done
  1. 1 Ask: why does your heart beat faster when you exercise? What is it pumping and why?
  2. 2 Introduce the circulatory system: heart pumps blood through two loops — pulmonary (to lungs) and systemic (to body).
  3. 3 Describe what blood carries: oxygen and nutrients to cells; carbon dioxide and waste away from cells.
  4. 4 Introduce blood vessels: arteries carry blood from the heart under high pressure, veins return blood to the heart, capillaries allow exchange at tissues.
  5. 5 Describe blood components: red blood cells (oxygen), white blood cells (defence), platelets (clotting), plasma (liquid carrier).
  6. 6 Measure resting and post-exercise pulse — count beats per 15 seconds and multiply by 4.
  7. 7 Ask: what happens to pulse rate during exercise? Why?

Tap a step to mark it as done.

Variations

  • Graph heart rate data before, during, and after exercise — observe the recovery curve.
  • Discuss heart disease: how does diet, exercise, and smoking affect the circulatory system?
  • Compare human circulation to that of a fish — a single loop vs double loop.
More information

Teach: artery, vein, capillary, pulse, circulation, oxygenated, deoxygenated, plasma, platelet. The double circulation concept — two loops from the same heart — is the key conceptual challenge.

Focus on the single journey: heart to lungs to heart to body to heart. Add vessel types and blood components once this basic circuit is established.

Can students trace the path of a red blood cell from the heart to the lungs and back? Can they name the three blood vessel types and state the key difference between each?

No resources needed. Measuring pulse requires only two fingers and a count. Draw the circulation diagram in soil.

Students often think veins always carry deoxygenated blood. The pulmonary vein carries oxygenated blood from the lungs to the heart.

The circulatory system connects biology to health science, exercise physiology, and medicine.

Activity details
Secondary Medium 25 minutes no prep Whole Class, Small Group Indoor & Outdoor
Topics
Circulatory System Heart Blood