My heart pumps blood

Blood moves fast. And my heart is what makes it move. Blood leaving my
heart right now will travel all the way to my toes and back again in
about one minute.

Inside my body are thousands of tubes called arteries and veins. My
heart pumps blood through these tubes to all the parts of my body.
That’s what my heart is doing when I put my hand on my chest and feel a
thumping.

Blood flows away from my heart through my arteries. The blood is fresh.
It carries oxygen from my lungs to all the cells of my body.

Blood flows back to my heart through my veins. This blood is not fresh.
It has given up its oxygen. Now it carries carbon dioxide from all the
cells in my body.

My heart pumps the used blood through my lungs. There the blood trades
the carbon dioxide for oxygen. Then my heart pumps the fresh blood into
my arteries and back through my body.

Blood has red cells in it. The red cells are workers. They carry oxygen
and carbon dioxide.

Blood has white cells in it, too. These are fighters. They kill germs
and help me stay strong and healthy.