Final answer:
The Eustachian tube links the nasopharynx with the middle ear, helping to equalize pressure and prevent discomfort or hearing issues.
Step-by-step explanation:
The Eustachian tube is a flattened tube connecting the nasopharynx to the middle ear, which functions to equalize pressure in the tympanic cavity. Actions such as yawning or swallowing open the Eustachian tube, and balancing pressure across the tympanic membrane. Without this pressure regulation, we might experience discomfort or even hearing issues due to pressure differences caused by altitude changes or other factors. When we yawn or swallow, the eustachian tube opens, allowing air to flow into or out of the middle ear, which helps to equalize the pressure on both sides of the eardrum. This prevents discomfort and potential damage to the eardrum that can occur due to unequal pressure.
For example, when we travel to higher altitudes, the external air pressure decreases while the middle ear pressure remains the same, causing a pressure difference that can be painful. The eustachian tube helps to equalize this pressure difference and relieve discomfort.