TABLE OF CONTENTS CHAPTER 1 Blood Highway 4 CHAPTER 2 The Heart of It All 10 CHAPTER 3 Beat by Beat 14 ACTIVITIES TOOLS Try This 22 Glossary 23 Index 24 To Learn More 24
CHAPTER 1 BLOOD HIGHWAY 4 CHAPTER 1 You run to the park You breathe deeply Your chest pounds Why That’s your heart It is working hard
CHAPTER 1 5 Check your pulse Do you feel how fast your heart beats It has to pump blood all over your body It is the main organ of the circulatory system This system controls how blood flows and where it goes
