We have been investigating how the respiratory system works over the last week.

We discovered that when we inhale oxygen it travels down the windpipe into two large tubes called bronchus and then into small tubes called bronchiole ( that look like hairs).

At the end of the bronchiole is the alveoli  (little air sacks) where the air get absorbed into our blood. We discovered we can have 600 million alveoli in the lungs.

Have a look at the model lungs we created using straws, toothpicks and raisins.