Ethmoidal air cells

The ethmoidal air cells (or less commonly, the ethmoidal sinuses) form one of the four pairs of paranasal sinuses. They are located within the single, midline ethmoid bone. They are present at birth, and they develop rapidly from 0-4-year-old; they further mature from 8-12-year-old during puberty.

  • location: between the orbit and the nasal cavity, within the ethmoid labyrinth of the ethmoid bone
  • blood supply: supraorbital, anterior and posterior ethmoidal and sphenopalatine arteries
  • innervation: anterior and posterior ethmoidal and supraorbital nerves

A collection of air cells (3-18 in number) divided by bony septa within the lateral mass, or labyrinth, of the ethmoid bone

Separated into anterior and posterior groups by the basal lamella, the lateral attachment of the middle turbinate to the lamina papyracea. Historically the ethmoid sinuses were subdivided into 3 groups of air cells: the anterior, middle and posterior ethmoidal air cells. The so-called middle group are now incorporated into the anterior group.

The anterior ethmoidal air cells drain to the hiatus semilunaris and middle meatus via the ethmoidal bulla, which form parts of the ostiomeatal complex. The posterior ethmoidal air cells drain to the superior meatus and sphenoethmoidal recess 2.

Some of the ethmoidal air cells have their own name, because of their importance in surgical procedures or their involvement in head and neck pathologies:

From the ophthalmic branch of the internal carotid artery, the supraorbital, anterior and posterior ethmoidal arteries supply the ethmoid sinuses with the sphenopalatine artery (a branch of the maxillary artery) also contributing. Thus, the ethmoid sinuses are supplied by branches of both the internal and external carotid arteries. 

Lymph from the ethmoid sinuses drains to the submandibular and retropharyngeal group of nodes.

The posterior ethmoidal air cells, along with the sphenoid sinus, is supplied by the posterior ethmoidal nerve whereas the anterior ethmoidal nerve supplies the anterior ethmoidal air cells. Both these nerves being extraconal branches of the nasociliary nerve, a branch of ophthalmic division of the trigeminal nerve

Head and neck anatomy
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Article information

rID: 25383
System: Head & Neck
Section: Anatomy
Synonyms or Alternate Spellings:
  • Ethmoidal air cell
  • Ethmoidal sinuses
  • Ethmoid sinuses
  • Ethmoid air cells
  • Ethmoid air cell

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