CorpusHuman Anatomy
RespiratoryOrgan part

Nasal conchae and meatuses

Conchae nasales

Also known as: turbinates, nasal meatuses, turbinate bones

Three curved shelves of bone covered with vascular mucosa on the lateral nasal wall; the air channels beneath them (meatuses) receive the openings of the paranasal sinuses and nasolacrimal duct.

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Overview

The superior and middle conchae are processes of the ethmoid bone; the inferior concha is a separate bone. Each overhangs a meatus of the same name, and above the superior concha lies the spheno-ethmoidal recess. The conchae greatly increase the mucosal surface area, generate turbulent airflow that deposits particles on mucus, and contain cavernous venous plexuses that can swell or shrink to regulate airflow and warming.

Under the middle concha lie the ethmoidal bulla (bulging middle ethmoidal cells) and the crescentic semilunar hiatus, which leads into the ethmoidal infundibulum. This crowded region — the ostiomeatal complex — is the common drainage pathway of the frontal, maxillary and anterior ethmoidal sinuses, and its obstruction is central to chronic rhinosinusitis.

Location

Lateral wall of each nasal cavity.

Parts & subdivisions

  1. Spheno-ethmoidal recess
    Above and behind the superior concha; receives the sphenoid sinus.
  2. Superior meatus
    Receives the posterior ethmoidal cells.
  3. Middle meatus
    Receives the frontal sinus (via the frontonasal duct/ethmoidal infundibulum), the maxillary sinus and anterior ethmoidal cells (semilunar hiatus), and the middle ethmoidal cells (on or above the ethmoidal bulla).
  4. Inferior meatus
    Receives the nasolacrimal duct (guarded by the lacrimal fold/valve of Hasner) — which is why crying makes the nose run.

Anatomy

Innervation

CN V2 (posterior superior lateral nasal nerves) and CN V1 (anterior ethmoidal nerve); autonomic fibres via the pterygopalatine ganglion control glands and vascular engorgement.

Arterial supply

Mainly the sphenopalatine artery (posterior lateral nasal branches) and ethmoidal arteries.

Function

  • Increase mucosal surface area for warming and humidifying air.
  • Create turbulence that deposits inhaled particles on the mucus blanket.
  • Regulate nasal airflow through their erectile venous plexuses (nasal cycle).

Clinical significance

Turbinate hypertrophy

Chronic rhinitis can enlarge the inferior conchae and obstruct airflow; decongestants (α-agonists) shrink the venous plexuses, but prolonged use causes rebound congestion (rhinitis medicamentosa).

Functional endoscopic sinus surgery

Opens the ostiomeatal complex in the middle meatus to restore drainage of the frontal, maxillary and anterior ethmoidal sinuses.

Mnemonics

What drains where

"Sphenoid sits high (spheno-ethmoidal recess), tears drain low (inferior meatus), posterior ethmoids go superior, and everything else goes to the middle."

Compiled from standard anatomy and physiology references — see the Respiratory System sources. For education only; not medical advice.