Science The Human Body Conceptual 9–11 yrs

Heart & Blood Circulation

心脏与血液循环

Description

Describe the circulatory system in detail: the heart has four chambers (two atria, two ventricles) that pump blood in a double loop — one to the lungs for oxygen and one to the rest of the body to deliver it — through arteries, veins, and tiny capillaries

Mastery Evidence

✓ Name the four heart chambers and describe the double-loop pathway (heart → lungs → heart → body)
✓ Distinguish arteries (carry blood away from heart), veins (carry blood back to heart), and capillaries (tiny vessels where exchange happens)
✓ Name the components of blood: red blood cells (carry oxygen), white blood cells (fight infection), platelets (help clotting), plasma (liquid)

Assessment Prompt

Can your child trace the path blood takes through the heart and body — explaining that it goes to the lungs first for oxygen, then out to the rest of the body?