by Catherine Gayfer
Year 11 Physical Education students have recently been studying the Cardiovascular and Respiratory systems.
Using common household items, students enjoyed building a working model of the lungs to illustrate the mechanics of breathing. As the balloon is pulled downwards, this action models the diaphragm contracting which increases the volume of the thoracic cavity (the bottle), which decreases the ‘intrapleural pressure’ (inside the bottle), thus drawing air into the lungs, as air moves from high to low pressure, which inflates the smaller balloons inside the bottle.
