Nasal cavity, paranasal sinuses, nasopharynx



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PubMed Search: Anatomy[TI] nasal cavity[TIAB]

Margaret S. Brandwein-Weber, M.D.
Page views in 2024 to date: 1,265
Cite this page: Sun J. Anatomy. website. Accessed July 13th, 2024.
Definition / general
    Nasal vestibule, nasal cavity, paranasal sinuses and nasopharynx

    Nasal vestibule:
    • Slight dilation inside anterior aperture of nostril, lined by skin containing hair and sebaceous glands
    • Anterior boundary: nares
    • Posterior boundary: line dropped perpendicular from the frontonasal suture through the anterior aspect of the inferior turbinate
    • Lateral boundary: ala and lateral crus of greater alar cartilage
    • Medial boundary: medial crus of greater alar cartilage
  • Nares: anterior openings of nasal cavity

Nasal cavity:
  • Nasal chambers are on either side of median plane formed by nasal septum
    • Anterior boundary: continuous with the vestibule
    • Posterior boundary: posterior choanae
    • Superior boundary: cribriform plate
    • Inferior boundary: hard palate
    • Medial boundary: nasal septum
    • Lateral boundary: lateral nasal wall with maxillary and ethmoid ostia and turbinates
  • Divided into olfactory region (superior nasal turbinates and opposed septum) and respiratory region (rest of cavity)
  • Bulla ethmoidalis: elevation on lateral wall of middle meatus, site of opening of middle ethmoid meatus
  • Choanae: posterior opening of nasal cavity, communicates with nasopharynx
  • Columella: anterior extreme nasal septum
  • Crista galli: bony ridge which projects superiorly from cribriform plate
  • Lateral wall: contains superior, middle and inferior nasal turbinates (conchae); below each is corresponding nasal passage or meatus
  • Limen nasi: posterior lateral ridge separating the vestibule from the nasal cavity
  • Middle meatus: below and lateral to middle turbinate
  • Nasal septal swell body: thickened area of superior nasal septum containing nasal erectile vessels
  • Olfactory cleft: narrow vertical aspect of superior nasal cavity
  • Party wall: comprised of the lateral nasal wall and medial antral wall
  • Sphenoethmoidal recess: above superior turbinate, site of opening of sphenoidal sinus
  • Superior meatus: along upper border of middle turbinate, site of opening of posterior ethmoid meatus
  • Turbinates (concha):
    • Scroll-like projections of bone and vascular soft tissue
    • The superior turbinate is smallest, the inferior turbinate is largest
    • Attaches to the lateral nasal wall anteriorly, with a free edge posteriorly

Paranasal sinuses:
  • Diverticula of nasal cavity that extend into neighboring bones
  • Frontal Sinuses:
    • Most anterior, above the orbits
    • Small / rudimentary at birth
    • Develop through puberty
    • Paired sinuses between the interior and external cranial tables
  • Ethmoid Complex:
    • Between the orbits
    • Well developed at birth
    • Paired sinus complex composed of 3 to 18 cells that are grouped as anterior, middle or posterior, according to the location of their ostia
    • Medial boundary: upper nasal fossa
    • Lateral boundary: lamina papyracea of the orbit
    • Superior boundary: fovea ethmoidalis, which is the medial extension of the orbital plate of the frontal bone
  • Sphenoid sinuses:
    • Most posterior at base of brain
    • Small / rudimentary at birth
    • Develop rapidly during childhood until permanent teeth develop
    • Posterior to the ethmoid sinuses
    • Superior boundary: floor of the anterior cranial fossa, anteriorly
    • Posterior boundary: optic chiasm and the sella turcica, posteriorly
    • Lateral boundary: orbital apex, the optic canal, the optic nerve and cavernous sinus
    • Inferior boundary: nasopharynx
    • Anterior boundary: nasal fossa
  • Maxillary sinuses:
    • Under the cheeks
    • Small / rudimentary at birth
    • Develop rapidly during childhood until permanent teeth develop
    • Medial boundary: lateral wall of the nasal cavity ("party wall")
      • The curved posterolateral wall separates the sinus from the infratemporal fossa
    • Anterior boundary: the facial surface of the maxilla
    • Inferior boundary: hard palate
    • Superior boundary: orbital rim and orbital apex
  • Ohngren line:
    • Connects medial canthus of eye to angle of mandible
    • Used to divide maxillary sinus into anteroinferior portion (infrastructure), associated with good prognosis for carcinoma and superoposterior portion (suprastructure), with a poor prognosis for carcinoma

  • Respiratory passage above and behind the soft palate
  • Part of pharynx, which also includes oropharynx and hypopharynx
  • Begins anteriorly at posterior turbinates and extends along plane of airway to the level of the free border of the soft palate
  • Anterior wall is perforated by posterior nares (choanae)
  • Posterior wall is also its roof, as well as the posterior base of skull
  • Extends inferiorly to level of free border of soft palate where oropharynx begins
  • Lateral wall contains ostium of eustachian tube, surrounded by mucosa covered cartilaginous prominence
    • Ostium is anterior to pharyngeal recess (fossa of Rosenmuller)
Diagrams / tables

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Lateral wall

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Bones and cartilages

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