1. The Nose Vibrissae Naris Apex (tip) Root Ala Dorsum
The external nose
Columella = skin that seperates the naris

2. External Nose

3. Internal Nose Vestibule Nasal Cavity Proper Skin
Very sensitive to pain
Hair (Vibrissa)
Limen nasi
Mucosa - Respiratory and Olfactory
Not so sensitive to pain

4. Nasal Cavity Piriform aperture Nasal septum divides to cavities
Tear drop shaped boney opening to the nasal cavity
Nasal septum divides to cavities

5. Bones that contribute to the nose and nasal cavity
Frontal
Maxilla
Ethmoid
Inferior Concha
Sphenoid
Palatine
Vomer
Lacrimal

6. Bones of the Nasal walls
Roof of cavity is made up of four bones
Anterior = frontal &nasal
Middle = ethmoidal (cribriform plate)
Posterior = Sphenoid
Lateral Wall
Superior and middle concha are ethmoidal bone
Inferior concha is its own bone
Small piece of lacrimal bone can be observed
Floor
Same bones as hard palate
frontal

7. Bones of the Septum cartilage Ethmoid Vomer bone Palatine and Maxilla
Septal cartilage extends into vestibule
Vomeronasal cartilageif present extends off vomer bone
Ethmoid
Perpendicular plate extends down from cribriform plate
Crista galli is a superior extension
Vomer bone
Triangle o f bone in inferior posterior nasal septum
Palatine and Maxilla
form ridges that extend up into nasal cavity
Vomer bone slots into these crests

8. Nasal Concha
There are three (sometimes four) turbinates on the lateral wall (called concha)
Inferior,Middle, Superior and Supreme (if present)
Concha are covered in respiratory epithelium (or olfactory epithelium near cribriform plate.
Epithelium serves for heat exchange and to humidify air
Bowman's glands secret mucus which coats epithelium
Microvilli of epithelium beat down and back to move the mucus towards the nasopharynx.
Spaces that allow air flow are meatus and named for the concha above them
Note space superior and posterior to superior concha is the sphenoethmoidal recess
Common meatus is the space between all concha and the septal wall
Inferior meatus

9. Nasal Concha

10. Nasal Concha a) Superior concha b) Middle concha c) Inferior concha
Superior meatus
Middle meatus
Common meatus
Inferior meatus a 1 b 2 3 c 4

11. Nerves of the nasal cavity

12. Nerves Three major nerves Vestibule is the most sensitive
CN I, V1, V2
Vestibule is the most sensitive
Infraorbital and anterior ethmoidal nerves
Nasal mucosa supplied primarily by V2
Anterior by V1 lateral nasal anterior ethmoidal
Small part for alveolar

13. Nerve summery

14. Blood Supply to Nasal Cavity

15. Arterial and Venous supply
Blood supplied from both internal and external carotid arteries
Anterior and posterior ethmoidal come off the ophthalmic artery (from internal carotid)
Maxillary branches off the external carotid
Facial originates from external carotid
Venous plexus of the lateral wall and septum
Venous plexuses are important for heat exchange
Plexuses can dilate and constrict controlling the aperture of the nasal meatus
Venous pathways are roughly the same as the arteries
Drainage occurs into the sphenopalatine, facial, or ophthalmic veins
Ultimately the pharyngeal or pterygoid plexuses

17. Epistaxis Anterior nasal septum is the Kiesselbach area
Plexus of all five arteries supplying the septum
Epistaxis = nose bleed
Generally minor nose bleeds are from arterial of venous plexus
Spurting of blood likely larger artery (e.g.sphenopalitine)

18. Blood Summery

19. Sinuses
Sinuses are air filled spaces extensions of the respiratory epithelium
They are named for the bones that they are in: Frontal, Ethmoidal, Maxillary, Sphenoid.
They serve to expand the surface area of the epithelium to increase heat exchange and aid in humidifying air
They produce mucus which must drain into the nasal cavity through various openings to the nasal cavity.
Because they are continuous with the nasal cavity infections in the nasal cavity often spread to the sinuses.
Because of the small openings of the sinuses often times the they can become obstructed during infections.

20. Nasal Sinuses Sinuses continue to develop into adulthood Frontal
Each grows in size taking over more of the bone
Generally stops or decreases in speed around puberty
Frontal
Rarely symmetrical
Innervated by supraorbital nerve (V1)
Ethmoidal
20-24 individual cells
Innervated by anterior and posterior ethmoidal nerves (V1)
Sphenoid
Derived from posterior ethmoidal sinus cells
Develops after age of 2
Innervated by posterior ethmoidal nerve
Maxillary
Largest sinus
Innervated by alveolar nerves

21. Sinus MRI
Ethmoidal and Maxillary sinuses are obvious

22. Sinuses Ethmoidal and maxillary sinuses are visible
Ethmoidal drainage through multiple ducts.
Anteriorly into the ethmoidal infundibulm which leads to the middle meatus
Middle directly into the middle meatus (are the air cells that make up the ethmoidal bulla)
Posterior drain into the superior meatus
Maxillary Sinus drains through the maxillary ostium through the semilunar hiatus and into the middle meatus

23. Sinus Drainage

24. Sinus Drainage

25. Sinus Drainage Note how Frontal and Maxillary Sinuses Drain
Ethmoidal infundibulum leads to the middle meatus
Semilunar hiatus leads to the middle meatus

26. Sinus drainage

27. Rhinitis
Nasal mucosa becomes inflamed due to infection or allergic reaction
Can be acute or chronic
Sinusitis
Sinus mucosa becomes inflamed due to infection generally for nasal cavity
Nasal Polyps
Noncancerous outgrowths of respiratory mucosa that can block airflow
Deviated Septum
Septal cartilage is deviated from the midline

29. Development