Ahmed had a severe throat infection. After a few days he developed an earache too. What could be the reason for the pain in his ears? Explain.

The infection spread from his throat to his middle ear through the EUSTACHIAN TUBE.

The Eustachian tube connects the middle ear cavity to the PHARYNX (throat). Because it is a direct passage, bacteria from a throat infection can travel along it and infect the middle ear, causing inflammation and earache.

The structure that must be named is the EUSTACHIAN TUBE, and the explanation must say WHAT IT CONNECTS — middle ear to throat.

ITS NORMAL FUNCTION is quite different and worth giving if you have room: it EQUALISES AIR PRESSURE on the two sides of the eardrum. That is why your ears "pop" in an aeroplane or on a mountain road, and why swallowing or yawning relieves the blocked feeling — both open the tube.

So the same passage that protects the eardrum from bursting also gives infection a route in. Middle-ear infection is commoner in children because their Eustachian tube is shorter and more horizontal.