Grade 3 · Science · Lesson 26

Circulatory and Respiratory Systems

Two of the most important body systems are the circulatory system and the respiratory system. They work closely together: the respiratory system brings oxygen into the body, and the circulatory system distributes that oxygen to every cell.

What this lesson teaches

1Identify the organs of the circulatory and respiratory systems
2Match each body part to the system it belongs to
3Explain how the circulatory and respiratory systems work together

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