Rhys and Megan are on a camping trip. As they reach their destination it’s clear that Rhys is out of breath. Rhys asks Alfred, his science app, for advice on how to pitch a tent. Alfred explains that in order to pitch a tent correctly, he must first be breathing correctly. Alfred takes Rhys step by step through the process of gas exchange. Using diagrams, the structure of the respiratory system is shown and then the structure and adaptations of the alveoli. An animation shows the process of gas exchange in the alveoli, with the oxygen diffusing from the alveoli into red blood cells and the carbon dioxide diffusing from the plasma back into the alveoli.
This clip could be used to introduce the topic and encourage students to consider how air gets into the body and then oxygen into the blood stream. This could lead to discovering why we increase our breathing when our muscles are working. The students could investigate the effect of exercise on breathing rate and tidal volume. Discussions on the effects of pollution, smoking and diseases such as asthma could stem from this.