<p><strong>Fig. 9.15.</strong> Air spaces in the head include the middle ear, the Eustachian tube, the nasal sinuses, and the throat. These areas respond to changes in pressure.</p>

Fig. 9.15. Air spaces in the head include the middle ear, the Eustachian tube, the nasal sinuses, and the throat. These areas respond to changes in pressure.

Image by Byron Inouye