After emerging from the nostrils via CGI, the presenters discuss the anatomy of the breathing system. The mechanism of breathing is described using an animation: active inhalation and passive exhalation.

First broadcast:
21 November 2008

If obtainable, the teacher could demonstrate a dissection of animal lungs, and students could have a look. Students could be challenged to build a pair of 'lungs' using straws and two balloons. These models would be like human lungs in that they cannot expand on their own, but require muscles to draw air in.
Students could draw a step-by-step process of the breathing apparatus and process.