6. EXTERNAL NOSE
Triangular pyramidal shape
Highest point of the nose is referred to as apex or tip of nose
Thin upper part that connects with the forehead is called as the root
Region between apex and root is called dorsum
Small curve below the root is called bridge
Below the apex is nostrils
7. NOSE
BONY PART
âą 2 nasal bones â nasale dextrum and sinistrum
âą Forms bridge of nose
CARTILIGENOUS PART
âą Remainder is cartilegenous part
âą Flexible
âą Connective and soft tissues
8. 5 CARTILAGES OF NOSE
ï±Lateral nasal cartilage
ï±Major ala cartilage
ï±Minor ala cartilage
ï±Accessory nasal cartilage
ï±Septal nasal cartilage
9. MUSCLES OF EXTERNAL NOSE
1) Procerus muscle- helps depress the medial
eyebrow and wrinkles the skin
2) Nasalis muscle- dilates the nares and flares
them
3) Depressor septi muscles- assists nasalis
muscles
12. NASAL CAVITY
Space behind the nostrils
Seperated into right and left nasal cavities by
nasal septum
3 sections of the nasal cavity
13. SECTIONS OF NASAL CAVITY
1) NASAL
VESTIBULE
2) RESPIRATORY
REGION
3) OLFACTORY
REGION
14.
15. VESTIBULE
Area surrounding the anterior external opening
to the nasal cavity
Lined with skin tissue unlike the rest of the
nasal cavity
Surrounded by the wings of nose and the nasal
septum
Floor- hard palate
16. RESPIRATORY REGION
Wide space within the nose covered with
ciliated pseudostratified epithelium
Mixed with mucus secreting goblet cells
17.
18. OLFACTORY REGION
Located at apex of the nasal cavity
Lined by olfactory cells with olfactory receptors
2 patches of olfactory receptors in each nasal
cavity located beneath the 2 olfactory bulbs
This region connects the nose to olfactory
centre of the occipital lobe
19.
20.
21. NASAL CONCHA
Projecting out of the lateral walls of the nasal cavity are curved shelves of
bone. They are called conchae (or turbinates).
The are three pairs of conchae
Inferior Middle Superior
22.
23. INFERIOR CONCHAE
Longest and broadest of the 3 concha
Extends horizontally along lateral wall of the nasal cavity
26. NASAL MEATUS
The conchae creates 4 pathways for air flow called as the meatus.
Inferior meatus: between inferior and floor of nasal cavity
Middle meatus: between inferior and middle concha
Superior meatus: between middle and superior concha
Spheno ethmoidal recess: superiorly and posteriorly to superior
concha
27. BOUNDARIES
Each half of the nasal cavity has :
ï roof
ïFloor
ïMedial wall
ïLateral wall
Each half diameter about 5 cm in height , 5-6cm in length, 1.5 cm in
width and 1-2 mm at the roof.
Roof is formed by cribiform plate of ethmoid bone
Floor is formed by palate which seperates oral cavity from nasal cavity
28. OPENINGS
Paranasal sinuses opens into the nasal cavity
All the sinuses except sphenoid sinus drains into the lateral wall. The
sphenoid sinus drains into posterior roof
Nasolacrimal duct also opens into the nasal cavity. Naso is nose and
lacrimal is tear gland
Auditory tube: it opens at the level of inferior meatus.
29. BLOOD SUPPLY
Branches of carotid artery provide the arterial supply
ï Internal carotid artery and external carotid artery
ï These arteries anatomise with each other in the nasal cavity
Venous drainage
- pterygoid plexus
- facial vein
30. KISSELBACHâS PLEXUS
Also known as the littleâs area
It is very vascular area
4 arteries anastomose in this area to form the kisselbachâs plexus
Situated at the anterior inferior part of the nose
Most common site of nose bleed
31. WOODRUFF AREA
It is a plexus of veins
Situated inferior to posterior end of inferior turbinate
Site of posterior nasal bleed
32. BLOOD SUPPLY
Olfactory nerves helps in the sense of smell
ï Lies on superior surface of cribriform plate
Nasopalantine nerve
ï Maxillary nerve
Nasociliary nerve
Opthalmic nerve
Trigeminal nerve
33. PHYSIOLOGY
The nose is an olfactory and respiratory organ
Consists of nasal skeleton which houses nasal cavity
Functions of nose:
1. warms and humidifies air
2. removes and traps pathogens and smaller particles
3. sense of smell
4. drains and clears sinuses and lacrimal duct
5. increases surface area to allow more air to enter
6. disrupts fast laminar flow of air
7. Allows proper functioning of ears
34. 1. WARMS AND HUMIDIFIES AIR
This is done by the function of concha and the rich blood supply of
the nose.
The blood supply of nose carries heat from the body which is
dissipated into the inhaled air during inhalation
Also the concha slows down the speed of air entering the nose
allowing adequate time for the air to be humdified before it enters
the lungs.
35. 2. REMOVES AND TRAPS
PATHOGEN / PARTICLES
The pseudostratified columnar epithelium with its goblet cells
secretes mucus , a thick sticky substance which traps any pathogen
or particles entering the nose.
The mucociliary action of the pseudostratified columnar epithelium
than causes the removal of the mucus out of the cavity thus not
allowing any micro organism or particle entry into the respiratory
tract.
36. 3. SENSE OF SMELL
The olfactory nerve branches runs through the cribriform plate to
provide sensory innervation to the nose. It thus helps in the sense of
smell.
37. 4. DRAINS AND CLEARS SINUSES
AND LACRIMAL DUCTS
The nasolacrimal system helps to drain the tears formed in the eyes
The paranasal sinuses opens into the nose allowing it to be drained
out into the nasal cavity. This helps in prevention of accumulation of
fluid into the sinuses which can lead to sinusitis
38. 5.ALLOWS MORE ENTRY OF AIR
The nasal concha increases the surface area of the nose which allows
the entry of more air during inspiration
39. 6. DISRUPTS FAST LAMINAR AIR
FLOW
The nasal conchae also helps in reducing the speed of air flow as it
can damage the respiratory tract. The conchae due to its horizontal
pathaways allows a more controlled entry of air.
40. 7. HELPS IN PROPER FUNCTION OF
THE EAR
The eustachian tube (auditory tube) opens into the nasal cavity. It
allows the middle ear to equalise with the atmospheric pressure.