3.8.5: Lung elasticity

The lungs have inward elasticity. This works towards decreasing the lung volume. The larger the lung volume, the larger the elastic force.

Let's suppose that there are 'rubber bands' inside the lungs, and that they are lightly stretched. When the lung volume is increased, the 'rubber bands' are strongly stretched.
lung volumeminmin→maxmax
inward elastic forceminmin→maxmax
                     (within one quiet respiratory cycle)


1 The lungs have outward inward  elastic force. The force is larger smaller  when the lungs are increased in volume.

2 The elastic force of the lungs is larger when the lungs are decreased increased  in volume.

3 The elastic force of the lungs is smaller when the lungs are increased decreased  in volume.


: Pleural pressure

: Lung volume, pressure inside the lungs and air flow-2