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The nasopharynx is the uppermost part of the pharynx, lying behind the nasal sinuses. As such, it is above what most of us think of as our 'throat space', and it is further removed from the mouth/throat complex by the velum (AKA the soft palate), which often rises up to shut the nasopharynx off from the oropharynx.

The nasopharynx does not play a role in swallowing; when the swallow reflex is triggered the velum rises up and pushes back to close off the nasopharynx so that food will not enter the nasal cavities. Other than during the swallow, the velum generally remains at least partly open, which is why you can still get milk up your nose when you laugh.

The velum needs to be open in order for you to breathe through your nose, and it needs to open and close regularly in order to talk normally; the /m/ and /n/ sounds are made by letting some sound energy escape through the nose, which resonates in the nasopharynx. You can demonstrate conscious control over your velum by talking in a hypernasal or hyponasal voice. Hypernasal voices, such as that of Fran Drescher's, result from too much air escaping through the nose during speech, while hyponasal voices result from nasal blockages, such as a stuffy nose.

The nasopharynx is bounded anteriorly by the posterior nasal choanae, which are the entryways to the nasal sinuses. The posterior and superior boundary is the pharyngeal protuberance of the occipital bone; on this surface you will find the pharyngeal tonsil, AKA the adenoids. The velum lies below, and the muscles that move the velum reside here, the levator veli palatini and the tensor veli palatini. The Eustachian tubes open into the lateral nasopharyngeal walls, and the lump that is formed by their exit point is an anchor site for the Salpingopharyngeus muscle and the levator veli palatini. The tensor veli palatini is the major muscle used to dilate the Eustachian tubes; when the tubes are dilated the pressure in your middle ears can equalize with the atmospheric pressure, which may make your ears pop. Opening the Eustachian tubes will also allow mucus to drain from your middle ears.

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