A marathon runner needs an efficient circulatory system.

• True

• False

In an efficient circulatory system, the blood picks up and delivers it to the muscles.

• oxygen quickly

• carbon dioxide slowly

Blood makes tissues look ...................in real life

• red

• yellow

• green

Scientific models use colour to make the circulatory system clearer.

• True

• False

The ..........................side of your heart pumps oxygen-poor blood through your lungs to pick up oxygen

• left

• right

The ........................side of your heart pumps oxygen-rich blood around the rest of your body.

• left

• right

The right side of your heart pumps .................................................. through your lungs to pick up oxygen

• oxygen-rich blood

• oxygen-poor blood

The left side of your heart pumps ............................... around the rest of your body.

• oxygen-rich blood

• oxygen-poor blood

Take blood from the heart to cells in your muscles, bones, and organs.

• Arteries

• Veins

• Capillaries

Channel blood to cells.

• Arteries

• Veins

• Capillaries