Eustachiusrøret

Eustachiusrøret, also known as the auditory tube or pharyngotympanic tube, is a narrow passageway connecting the middle ear to the nasopharynx. Its primary function is to equalize pressure between the middle ear and the surrounding environment. This pressure equalization is crucial for proper hearing, as significant pressure differences can hinder the vibration of the eardrum and the ossicles in the middle ear.

The Eustachian tube is typically closed at rest but opens during actions such as swallowing, yawning, or chewing. This opening allows air to flow in or out of the middle ear, adjusting the pressure to match that of the outside world. The lining of the tube is made up of mucous membrane, which helps to keep the passage moist and trap any foreign particles. Cilia within the tube also help to move mucus and debris towards the nasopharynx to be expelled.

Dysfunction of the Eustachian tube can lead to a variety of ear problems. If the tube becomes blocked, often due to inflammation from a cold or allergies, pressure can build up in the middle ear, causing discomfort, hearing loss, and a feeling of fullness in the ear. This blockage can also prevent proper drainage of fluids from the middle ear, potentially leading to infections like otitis media. Conversely, if the tube remains too open, a condition known as patulous Eustachian tube, a person might hear their own breathing or voice resonating loudly in their ears.