Shape of the nose
- upper end is root
- free tip is apex
Dorsum of nose
Extends from root to apex, in midline
What are the two inferior apertures of the nose?
The nares (nostrils)
What is each nostril limited by?
Laterally by the ala of nose
What is the supporting framework of nose composed of?
Bone and hyaline cartilage
What part of the nose does the bony framework support?
What does the bony framework consist of?
Nasal bonds and frontal processed of maxillae
What supports the lower part of the nose?
What does the cartilagenous framework consist of?
One septal and two major alar cartilages
What ar the cartilages connected to each other and the bone by?
What is the largest cartilage of the nose?
- Forms anterior part of the nasal septum
- Has 2 lateral processes (triangular in shap, located below inferior border of nasal bone
Major alar cartilages
-u-shaped, form lateral and medial borders of the nostrils (lateral and medial crura, respectively)
What is the nasal cavity?
Chamber consisting of bony cartilaginous walls, covered with mucosa
Where does the nasal cavity open?
Anteriorly on face via the nares
What does the nasal cavity communicate with posteriorly and by what?
Nasopharyngeal via posterior nasal aperture (choanae)
The area immediately above the nares
What is the vestibule lined with?
Skin and stiff hairs
Functions of nasal cavity
- conditioning of inspired air (filtration, humidification, warming)
- reception of secretions from paranasal air sinuses and nasolacrimal duct
Superior relationship of nasal cavity
Anterior cranial fossa separated by cribiform plate
Lateral to upper part of the nasal cavity
Ethmoidal air cells and orbit
Lateral to lower part of nasal cavity
Inferior relationship to nasal cavity
Oral cavity separated by hard palate
Posterior relationship to the nasal cavity
Nasopharynx via choanae
Composition of the bony walls of the nasal cavity: floor
Hard palate (palatine processes of maxillae and horizontal plates of palatine bones
Composition of the bony walls of the nasal cavity: roof
From anterior to posterior: nasal bone, nasal spins of frontal bone, cribiform plate of ethmoid, anterior and inferior aspects of body of sphenoid
Composition of the bony walls of the nasal cavity: medial wall (nasal septum)
Perpendicular plate of ethmoid and vomer ( and small contributions from sphenoid, maxilla, and palatine)
Composition of the bony walls of the nasal cavity: lateral wall
Maxilla, lacrimal bone, inferior nasal choncha, ethmoidal labyrinth, perpendicular plate of palatine, and medial pterygoid plate
What are the 3 scroll-like bony projections on the lateral wall f the nasal cavity?
Superior, middle, and inferior nasal conchae
What bones are the superior, middle, and inferior chonchae a part of?
Superior and middle belong to ethmoid, inferior concha is a separate bone
What is the space between each conchae and lateral wall called?
What are the 3 nasal meatuses?
Superior, middle, and inferior
What is the part of the nasal cavity that is located above and behind superior nasal concha?
Communications of superior nasal meatus
Posterior ethmoidal air cells open via small orifices in its lateral wall
Communications of the middle nasal meatus
- ethmoidal bulla
- semilunar hiatus
- ostium of maxillary sinus
Ethmoidal bulla of the middle meatus
Elevation in lateral wall of middle meatus cause by middle ethmoidal air cells
Semilunar hiatus in the middle meatus
Curved cleft anterior and inferior to ethmoidal bulla
Ostium of maxillary sinus in middle meatus
Located in lower part of semilunar hiatus
Infandibulum in the middle meatus
- superior end of semilunar hiatus leaders into this
- receives openings of anterior ethmoidal air cells
- in some individuals infandibulum also receives opening of frontal sinus
- in others, infundibulum has superior blind end, and frontal sinus opens directly into anterior part of middle nasal meatus
Communications of the inferior nasal meatus
Opening of nasolacrimal duct is located in anterior part of lateral wall
Communications of sphenoethmoidal recess
Opening of sphenoid sinus
Other than the vestibule, what is the entire nasal cavity lined with?
What is the nasal mucosa firmly bound to?
Periosteum and perichondrium of supporting structures
What is the nasal mucosa continuous with?
Mucosal lining of nasopharynx, paransal air sinuses, and nasolacrimal duct
Lines highest part of roof and adjacent parts of septum and lateral wall, contains olfactory receptor cells
Lines rest of nasal cavity
What is the general sensory nerve supply of the nasal cavity derived from?
Branches of the ophthalmic and maxillary nerves
General sensory nerve supply
- anterior ethmoidal nerve
- nasal branches of infraorbital nerve
- nasal branch of anterior superior alveolar nerve
- posterolateral nasal branches
- nasopalatine nerve
What is the anterior ethmoidal nerve a branch of?
The nasociliary nerve
Where does the anterior ethmoidal branch pass from?
Orbit to anterior cranial fossa view anterior ethmoidal foramen and runs forward on cribiform plate
What happens when the anterior ethmoidal nerve leaves the anterior cranial fossa?
Enters nasal cavity via small slit at side of crista galli
After the anterior ethmoidal nerve enters the nasal cavity, what does it divide into?
- Internal branches that supply mucosa of anterior parts of septum and lateral wall
- External nasal nerve supplies skin of lower part of nose
Nasal branches of infraorbital nerve supply what?
Skin of vestibule
Posterolateral nasal branches
- big nerve in posterior part
- originate from pterygopalatine ganglion or greater palatine nerve
- supply mucosa of posterior part of lateral wall
Nasopalatine nerve supplies what
Mucosa of posterior part of nasal septum
Olfactory receptor cells
Bipolar neutrons located in olfactory mucosa
Peripheral processes (dendrites) of olfactory receptor cells
Reach mucosal surface and give rise to nonmotiel cilia, which spread over mucosal surface
Central processes (axons) of olfactory receptor cells
- Join to form olfactory nerves
- pass through openings of cribiform plate
- end in olfactory bulb
Main source of arteries of the nasal cavity
Sphenopalatine and anterior ethmoidal arteries
- major posterior artery
- terminal branch of maxillary artery
- supplies posterior parts of lateral wall and septum
Anterior ethmoidal artery
- major anterior artery
- branch of ophthalmic artery
- supplies anterior parts of lateral wall and septum
Minor sources of arteries for nasal cavity
Posterior ethmoidal artery, superior labial artery, greater palatine artery
- on anterior part of septal cartilage, septal branches of sphenopalatine, greater palatine, anterior ethmoidal, and superior labial arteries anastomose with each other
- common site of epistaxis
Veins of nasal cavity
- form rich plexus in submucosa
- venous drainage is into pterygoid venous plexus, facial vein, and ophthalmic vein
Air spaces in frontal, maxilla, ethmoid, and sphenoid bones, lined by a mucous membrane continuous with that of nasal cavity
How do sinuses develop?
As evaginations of nasal mucosa
-mucosa invades beans surrounding nasal cavity, with secondary bone resorption around invading mucosal sacs
Sinus development throughout life
- rudimentary at birth
- there is a slow, continuous growth during childhood and a rapid growth during adolescence
- sinuses attain maximum size in adult
Functions of paranasal sinuses
- resonating chambers for voice
- lighten skull bones
What is the largest paranasal sinus?
Where is the maxillary sinus?
Within body of maxilla
Superior relationship of the maxillary sinus
Orbit and its contents (infraorbital canal runs along superior wall of sinus and creates a bony ridge)
Medial relationship to the maxillary sinus
Nasal cavity (maxillary ostium located high in medial wall, poor drainage in erect posture)
Inferior relationship to maxillary sinus
Maxillary alveolar process and roots of maxillary teeth (molar roots are closer to maxillary sinus than incisor roots)
What does the maxillary sinus communicate with?
Middle nasal meatus via an opening located in lower party of semilunar hiatus
Nerve supply to the maxillary sinus
Superior alveolar nerves that come up from below from teeth
Blood supply to the maxillary sinus
Superior alveolar arteries
Where is the frontal sinus located?
Within frontal bone, behind superciliary arches
Frontal sinus shape and size
Cary in size and are rarely symmetrical
Where doe the frontal sinuses usually extend?
Superiorly into frontal aquamarine and posteriorly into orbital plates (roof of orbit)
Where does the frontal sinus open into?
Middle nasal meatus
Nerve supply to frontal sinus
Blood supply to the frontal sinus
Ethmoidal air cells
Thin-walled spaces within ethmoidal labyrinths
Number of cells in ethmoidal air cells
3 to 18
Anterior ethmoidal cells open into
Infundibulum of middle nasal meatus
Middle ethmoidal cells open
I’m surface of ethmoidal bulla of middle nasal meatus
Posterior ethmoidal cells open
Into superior nasal meatus
Nerve supply of ethmoidal air cells
Anterior and posterior ethmoidal nerves
Blood supply of ethmoidal air cells
Anterior and posterior ethmoidal arteries
Sphenoidal sinuses location
Posterior to upper part of nasal cavity within body of sphenoid
Sphenoidal sinus related superiorly to
Pituitary gland and optic chasm
Sphenoidal sinuses related laterally to
Cavernous sinus and internal carotid artery
Sphenoidal sinus shape and size
Vary in size and are rarely symmetrical
Sphenoidal sinus opens into
Corresponding sphenoethmoidal recess
Nerve supply to sphenoidal sinuses
Posterior ethmoidal nerve, pharyngeal nerve
Blood supply of sphenoidal sinus
Posterior ethmoidal arterym pharyngeal branch of maxillary artery