Ethmoid sinus

Bone: Ethmoid sinus
Paranasal sinuses
Coronal section of nasal cavities.
Latin	cellulae ethmoidales
Gray's	subject #36 154
MeSH	Ethmoid+Sinus
Dorlands / Elsevier	c_19/12225634

The ethmoid sinus, one of the paranasal sinuses, is the collective name for the ethmoidal air cells.

Each ethmoid sinus is an air-space enclosed within the ethmoid bone. The ethmoidal air cells consist of numerous thin-walled cavities situated in the ethmoidal labyrinth and completed by the frontal, maxilla, lacrimal, sphenoidal, and palatine bones.

They lie between the upper parts of the nasal cavities and the orbits, and are separated from these cavities by thin bony laminæ.

Three groups

Anatomically, ethmoidal sinuses can be classified as the anterior, middle, and posterior ethmoid sinuses.

• The posterior drains into the superior meatus under cover of the superior nasal concha; sometimes one or more opens into the sphenoidal sinus.

• The middle drains into the middle meatus of the nose on or above the bulla ethmoidalis.

• The anterior drains into the middle meatus of the nose by way of the infundibulum.

Innervation

The ethmoidal air cells are innervated by the anterior and posterior ethmoidal nerves, and the orbital branches of the pterygopalatine ganglion.

Additional images

• 

  Ethmoid bone from the right side.

• 

  Left orbicularis oculi, seen from behind.

• 

  Lateral wall of nasal cavity; the three nasal conchæ have been removed.

External links

• SUNY Figs 33:04-07
• SUNY Labs 33:st-0711

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant. Template:Skull

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