Nasal cavity, paranasal sinuses, nasopharynx
General
Anatomy
Last author update: 1 February 2016
Last staff update: 6 October 2020
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PubMed Search: Anatomy[TI] nasal cavity[TIAB]
Cite this page: Sun J. Anatomy. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/nasalnormalanatomy.html. Accessed April 24th, 2024.
Definition / general
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Nasal vestibule, nasal cavity, paranasal sinuses and nasopharynx
- 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 vestibule:
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
Nasopharynx:
- 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
Images hosted on other servers:
Lateral wall
Bones and cartilages
