They form a protective cage for the delicate lungs and hears within.
Help ventilate the lungs
This fluid acts as a lubricant, reducig friction between the lungs and the rib cage during ventilation
Its movements aid the ventilation of the lungs
The mucus helps to clean the inhaled air by trapping dust and other particles on its sticky surface. The incoming air is also warmed as it passes through the nasal cavity.
Prevents choking caused by food entering the trachea.
Vibrate to produce sound when exhaled air passes over them.