The Human Heart and Circulatory System: Free KS2 Worksheet

What this worksheet covers

The worksheet focuses on three Year 6 ideas: that the heart is a muscular pump, that it has four chambers, and that blood vessels carry blood around the body. Children colour the heart diagram to distinguish its parts, then label the left and right atria (the two upper chambers), the left and right ventricles (the two lower chambers), and the major vessels branching from the top — the aorta, the pulmonary artery, the pulmonary vein and the vena cava. Pairing a colouring task with a labelling task helps children connect the visual structure of the heart to the correct vocabulary, which is a common assessment focus at the end of Key Stage 2.

How the heart and circulatory system work

The heart is a fist-sized muscle that pumps blood continuously around two linked loops. In one loop, the right side of the heart pushes oxygen-poor blood to the lungs, where it picks up oxygen and releases carbon dioxide. In the other, the left side pumps freshly oxygenated blood out through the aorta to the rest of the body. Blood travels away from the heart in arteries, returns in veins, and exchanges oxygen, nutrients and waste with cells in tiny capillaries. It is worth helping children understand that the heart's left and right are reversed on a front-on diagram, just as they would be when looking at someone facing you.

Teaching tips for parents and teachers

Before labelling, ask the child to place a hand on their chest and feel their heartbeat, then find a pulse at the wrist or neck — this links the diagram to something real. A simple colour key helps reinforce the science: colour vessels carrying oxygen-rich blood red and oxygen-poor blood blue. Encourage children to trace the journey of a single drop of blood with a finger, from the body into the heart, out to the lungs, back to the heart and out again. Common misconceptions to gently correct are that the heart is heart-shaped (it is not), that it sits on the far left (it sits roughly centrally, tilted left), and that blood is blue inside the body (it is always red, just darker when carrying less oxygen).

Extending the learning

Once children are confident with the parts of the heart, you can extend the topic to the functions of blood — transporting oxygen, nutrients and water, and carrying away waste such as carbon dioxide. Year 6 also asks pupils to recognise the impact of diet, exercise, drugs and lifestyle on how the body functions, so this worksheet pairs well with a discussion of how regular exercise strengthens the heart muscle and why a balanced diet keeps blood vessels healthy. A short measure-your-pulse-before-and-after-exercise investigation makes an excellent practical follow-up.

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