The Eustachian Tube is a tube between the back of the nose and the middle ear.  It is made up of cartilage and bone and there is approximately 3 ½ cm long in adults.  Of importance is that by the age of seven, the child’s Eustachian Tube is near adult size.  There are two main muscles that are attached to the tube and it is a dynamic structure.  It has the same lining as the upper respiratory system. 

There are two main functions of the Eustachian Tube.  The first is drainage of secretions from the middle ear and mastoid to the nasopharynx.  The second is that pressure equalizer especially with altitude changes such as flying and diving.  Of note is that the tube is usually closed and opens with swallowing, yawning and blowing air through the blocked nose up into the middle ear. 

Eustachian Tube explained: