(ks3) Heart And Lungs

Inside our bodies lie a number of `organs` - which are the main body parts (like small machines!) that control how are bodies work.

Two of the main ones (and probably the most important!) are the `heart` and the `lungs`. They work together to provide the body with nutrient-rich blood that keeps us alive and healthy.

The Lungs

We actually have two lungs, one either side of the main windpipe, and these lie in the chest under our ribs.

When we breath in, the lungs fill up with air that contains `oxygen`. Oxygen is a gas that our bodies need to make energy.

Blood passes through our lungs and picks up all the oxygen from the air in the lungs. The waste product of making that energy is `carbon dioxide` (another gas), which needs to be removed by the body.

When the carbon dioxide in the blood passes through the lungs, it moves into the air within the lungs and is blown away when we breath out!

Breathing in and out keeps those two gases in a perfect balance inside our bodies!

The Heart

We only have one heart, and it also sits inside the chest - in between the two lungs.

Its main job is really simple - to pump blood around the body!

The heart is actually just a special muscle, about the size of your fist, that squeezes to push blood to where it is needed.

The heart is divided into two halves. One side pumps the blood too and from the lungs, and the other side to and from the rest of the body - like the brain, muscles, and bones!

It`s that easy!