Middle nasal meatus

Bone: Middle meatus
Roof, floor, and lateral wall of left nasal cavity. (Middle meatus labeled at center right.)
Latin	meatus nasi medius
Gray's	subject #57 195

The middle meatus is a nasal opening or canal situated between the middle and inferior conchæ, and extends from the anterior to the posterior end of the latter.

The lateral wall of this meatus can be satisfactorily studied only after the removal of the middle concha.

On it is a curved fissure, the hiatus semilunaris, limited below by the edge of the uncinate process of the ethmoid and above by an elevation named the bulla ethmoidalis; the middle ethmoidal cells are contained within this bulla and open on or near to it.

Through the hiatus semilunaris the meatus communicates with a curved passage termed the infundibulum, which communicates in front with the anterior ethmoidal cells and in rather more than fifty percent of skulls is continued upward as the frontonasal duct into the frontal air-sinus; when this continuity fails, the frontonasal duct opens directly into the anterior part of the meatus.

Below the bulla ethmoidalis and hidden by the uncinate process of the ethmoid is the opening of the maxillary sinus (ostium maxillare); an accessory opening is frequently present above the posterior part of the inferior nasal concha.

Additional images

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  Left maxilla. Nasal surface.

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  Left palatine bone. Nasal aspect. Enlarged.

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  Left orbicularis oculi, seen from behind.

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  Coronal section of nasal cavities.

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  Sagittal section of nose mouth, pharynx, and larynx.

External links

• SUNY Figs 33:04-10
• Atlas of anatomy at UMich rsa1p6

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.