The Eustachian tubes help regulate air pressure equally on either side of the eardrum. Their tubes are more horizontal in orientation than those of an adult. The Eustachian tube has three functions: ventilation, drainage, and protection THE EUSTACHIAN TUBE –FUNCTION AND DYSFUNCTION. This allows air to get into the middle ear and any mucus to get out. The air in the middle ear is constantly being absorbed by the cells that line the middle ear Normal Function. The eardrum will be Brown Health Ser