Veins, Arteries and Capillaries

It needs to get oxygen and nutrients from the top to the bottom of your body and it manages this with the help of the body’s circulatory system.

The body has a network of blood vessels that carry blood around.

The way it works is quite similar to how traffic runs on the roads.

To keep traffic running smoothly, all the traffic travelling in the same direction will travel on the same part of the road and the same goes for blood vessels. Arteries travel in one direction, veins in the other.

What are arteries?

Arteries are the large vessels that carry blood through the heart, around to every part of your body.

The blood that arteries carry from the lungs is full of oxygen.

As they get closer to the surface or into smaller spaces, blood is transferred into microscopic vessels called capilliaries.

When the blood has released its oxygen, it returns back to the lungs and heart through veins.

What are veins?

If you could see the blood in your veins, it would look a lot darker than it was in your arteries.

The movement of the blood through the heart and around the body is called circulation – and your heart is really good at this.

Did you know?

It takes less than 60 seconds to pump blood to every cell in your body!

A cool thing is, it doesn’t matter if you’re standing on your head or jumping on a trampoline, blood keeps pumping – all the way around the body.

Clever doors called valves make sure that the blood can’t go the wrong way. Blood has to travel in one direction only.

Why are valves so important?

Well, if there’s a problem with them, it can make you feel very poorly.

Think of them like doors. Sometimes the valves don’t open enough to allow the blood to flow.

This is called stenosis and the heart has to work harder to push blood through.

A different type of problem can occur when the valves don’t shut properly.

When the valves don’t close properly, blood can leak backwards.

This is called regurgitation and your heart has to work harder to push it the right way.

They’ll be finding out all about the cool stuff that goes on inside your heart and how it manages to pump blood around your body all the time – even when you’re asleep!