Fun Facts About Blood Vessels and Cool Activities for Kids

Did you know that your body has 60,000 miles of blood vessels? These important tubes act like highways, carrying oxygen and nutrients in your blood to every cell in your body from head to toe. Get ready to learn many more fun facts about blood vessels and try cool activities, too!

3 types of blood vessels - artery, vein, capillary

Basic facts about blood vessels

Your amazing body has 3 types of blood vessels: arteries, veins, and capillaries.

  • ARTERIES are the thickest type of blood vessel. These vessels carry blood from the heart to other parts of the body. Because arteries have lots of fresh oxygen, they are usually shown as red squiggly lines in human body diagrams.
  • VEINS are slightly thinner than arteries. These vessels carry blood from parts of the body back to the heart. Because veins have less oxygen, they are usually shown as blue squiggly lines on human body diagrams.
  • CAPILLARIES are the tiniest vessels with very thin walls. Because these vessels connect arteries and veins, they are usually shown as purple squiggly lines on human body diagrams.

Blood vessels coloring page for kids

Hands-on activities can help kids remember facts about blood vessels, and this coloring page is fun and easy!

Color the artery red, color the vein blue, and then color the center of the capillaries purple. If you don’t know what colors to use, check out the picture at the top of this article.

“Fill the capillaries” activity template

This template can also be used for the “Fill the Capillaries” activity on pages 80 to 81 in the Human Body Learning Lab book!

Have you tried this fun experiment yet? You might discover that it works best with watercolor paper. Watercolor paper is thick and prevents water and paint from bleeding through the other side.

Complete the form below to sign up for updates and download this free printable template. Check your email after you hit “submit.”

Fun facts about blood vessels for kids

Here are some interesting blood vessel facts that might surprise you and your friends!

Blood never stops flowing

Thanks to your pumping heart, blood constantly flows through your body, even when sleeping or doing a headstand.

In just one minute, the heart can pump about 1.3 gallons (5 liters) of blood around the body.

They dance to the beat

Check radial pulse on side of wrist

Ever felt your pulse by placing your fingers on your wrist?

That’s the rhythmic beat of your heart pumping blood through your arteries.

The pulse you feel is like a dance, a steady rhythm that can change with exercise, excitement, or even fear.

It’s your body’s way of letting you know everything is flowing.

Explore this fun fact about blood vessels by dancing and checking your pulse after!

Blood is not blue

Have you noticed that blood vessels in people with light-colored skin have a bluish hue?

What you’re seeing are veins near the surface of your skin. But veins aren’t actually blue! The color you see is an optical illusion of light reflecting off your top skin layers.

The blood inside the veins is dark red, and people of all skin colors have dark red blood inside veins.

On the other hand, healthy blood in arteries is bright red. Why is the blood in arteries a vibrant red? You can thank a special protein called hemoglobin. Hemoglobin acts like a delivery truck, carrying oxygen around the arteries in your body.

Two blood vessels are supersized

The aorta is the largest artery in the body because it’s directly connected to the heart.

The vena cava is the largest vein in the body because it’s directly connected to the heart.

Most are tiny

Most of your circulatory system is made of capillaries, even though they are the smallest type of blood vessel.

They help you make pee

Here’s another fun fact that might surprise you: blood vessels have a cool connection to making pee!

When blood vessels flow through your kidneys – the bean-shaped organs in your belly – the kidneys get rid of garbage from your blood into your pee. Then, it leaves your body when you go to the bathroom!

Human Body Learning Lab anatomy book for kids

Human Body Learning Lab Fill the Capillaries

If you think blood vessel facts are cool, you’ll love learning more about the amazing human body!

Human Body Learning Lab has kid-friendly science facts, memorable experiments, captivating images, and practical health tips.

In addition to the circulatory system, the Human Body Learning Lab book has cool information about all major organ systems.