The anatomy of the external nose and the lateral and medial wall is explained including the blood supply and nerve supply

1. ANATOMY
& PHYSIOLOGY
OF NOSE

2. Nasal skin
• skin over nasal bone and upper lateral
cartilage is thin and freely mobile while that
on alar cartilages is thick and adherent and
contains sebaceous glands.
EXTERNAL NOSE

3. Nasal musculature
a) Procerus
b) Nasalis (transverse and alar part)
c) Levator labi superioris alaque nasi
d) Anterior and posterior dialator naris
e) Depressor septi

4. Osteo-cartilaginous framework
Upper 1/3rd- Bony
Lower 2/3rd- Cartilaginous
Bony framework
a) Nasal bones
b) Nasal processes of frontal bone
c) Frontal processes of maxilla

5. Cartilaginous
framework
a) Upper lateral cartilages
b) Lower lateral cartilages
(alar cartilages)
c) Lesser cartilages
(sesamoid cartilages)
d) Septal cartilage

6. • Blood supply
• Lymphatic drainage
– preauricular
– submandibular lymph
nodes

7. NERVE SUPPLY

8. • It is divided into right and left nasal cavity by nasal
septum.
Each nasal cavity consists of
a) Skin lined portion-vestibule (contains sebaceous
glands, vibrissae)
b) Mucosa lined portion-nasal cavity proper
INTERNAL NOSE

10. Nasal cavity proper
• Bounded by lateral wall, medial wall, roof and a floor
• Floor
• Palatine process of maxilla (anterior 3/4th )
• Horizontal process of palatine bone (posterior 1/4th )

11. • Anterior sloping part by
nasal bones
• Posterior sloping part by
body of sphenoid
• Middle horizontal part by
cribriform plate of ethmoid
through which olfactory nerves
enter the nasal cavity
Roof

12. Nasal septum consists of three parts
a) Columellar septum
b) Membranous septum (lies between columella
and caudal border of septal cartilage)
c) Septum proper: consists of osteocartilagenous
framework covered with nasal mucous membrane

13. Septum proper: principal constituents
a) Perpendicular plate of ethmoid postero- superiorly
b) Vomer infero-posteriorly
c) Septal cartilage (quadrilateral cartilage)
These articulate with following bones to complete the septum
a) Superiorly-frontal bone, nasal bone, rostrum of sphenoid.
b) Inferiorly anterior nasal spine of maxilla, nasal crest of maxilla and
palatine bones

14. • Medial wall of nasal cavity (nasal septum)

18. ANATOMY - LATERAL WALL OF NASAL CAVITY
a) Ascending process of maxilla
b) Nasal bone
c) Ethmoid
d) Medial part of maxilla
e) Inferior turbinate
f) Perpendicular plate of palatine bone
g) Medial pterygoid plate

19. ANATOMY - LATERAL WALL OF NASAL CAVITY

21. BLOOD SUPPLY-

22. SENSORY NERVE SUPPLY - NASAL CAVITY
• Common sensation
– Trigeminal nerve
• ophthalmic
• maxillary divisions.
• Special sensory (smell)
– Olfactory nerves.

23. • Sympathetic supply
– Superior cervical sympathetic ganglion
– Internal carotid plexus
– vidian nerve
– sphenopalatine ganglion.

24. • Parasympathetic supply
– facial nerve
– greater superficial petrosal nerve
– vidian nerve
– sphenopalatine ganglion.
– Nasal branches from sphenopalatine ganglion

25. LYMPHATIC DRIANAGE - NASAL CAVITY
• Upper deep cervical nodes drain the nasal cavity directly or via the
retropharyngeal nodes.

27. PARANASAL SINUSES
- ANATOMY
• These are air filled spaces
• Direct communication with
nasal cavity through their ostia
• Four on each side

28. Anterior group
a) Maxillary
b) Frontal
c) Anterior ethmoidal
Posterior group
a) Posterior ethmoid
b) Sphenoid

29. MICROSCOPIC ANATOMY
• Lined by mucus membrane
• Ciliated columnar epithelium
• Goblet cells secretes mucus
• Cilia are more marked near
ostia.

30. 60
PHYSIOLOGY
OF
NOSE

31. 61
Functions of the nose
1. Respiration.
2. Air-conditioning of inspired air.
3. Protection of lower airway.
4. Vocal resonance.
5. Nasal reflex functions.
6. Olfaction.

32. 74

33. 78
NASAL CYCLE
• Nasal mucosa undergoes rhythmic cyclical congestion and
decongestion, thus controlling the airflow through nasal
chambers.
• Nasal cycle varies every 2½ – 4 h and may be characteristic
of an individual.

34. Filtration and purification
• Nasal vibrissae at the entrance of nose act as filters and can filter particles
up to 3 μm .
• Finer particles like dust, pollen and bacteria adhere to the mucus which is
spread like a sheet all over the surface of the mucous membrane ,mucus
traps particles as fine as 0.5–3.0 μm.
• Particles smaller than 0.5 μm seem to pass through the nose into lower
airways without difficulty.

35. Temperature control of the inspired air
• Regulated by large surface of nasal mucosa.
• Mucous membrane, is highly vascular with cavernous venous spaces or
sinusoids which control the blood flow, and this increases or decreases the
size of turbinates.
• Inspired air which may be at 20°C or 0°C or even at subzero temperature is
heated to near body temperature (37°C) in one-fourth of second. Similarly,
hot air is cooled to the level of body temperature.

36. Humidification
• Nasal mucous membrane adjusts the relative humidity of the
inspired air to 75% or more.
• Water, to saturate the inspired air, is provided by the nasal mucous
membrane which is rich in mucous and serous secreting glands.
• About 1000 mL of water is evaporated from the surface of nasal
mucosa in 24 h.

37. PROTECTION OF LOWER AIRWAY
• Removing particles - 30 μm, pollens from the inspiredair
• Dust deposited in the nose
• Inspired air travels through 180o and velocity drops markedly just
after the nasal valve
• Turbulence increases deposition of particles
• Particles in motion - carry on in the same direction
• Resistance to change in velocity is greater in irregular particles
because of larger surface area and the number of facets
• Vibrissae will only stop the largest particles
80

38. 82

39. CILIA
Ultrastructure
• Found on the surface of cells in the respiratory tract
• Function: to propel mucus backwards
• All cilia have the same ultrastructure
• Nasal cilia - relatively short at 5 μm,
• Nasal cilia - with up to 200 per cell
• 9 paired outer microtubules surround a single inner
pair of microtubules
85

40. VOCAL RESONANCE
• Nose form resonating chamber for certain consonants in speech
• Phonating nasal consonants (M/N)
• Many nasal condition affect the quality of voice by blocking the
passage of air
• Rhinolalia clausa – too little air escapes from the nose
• Rhinolalia aperta – too much air escapes
90

41. OLFACTION
• Olfactory compound need high water and lipid solubility
• The solute in the mucus is presented to the sensory mucosa
Olfactory area
• Area: 200-400mm2
• Receptor cells
Stimulus
React with lipid bilayer of the receptor cells at specific sites cells
depolarization
91

42. OLFACTORY PATHWAYS
• Olfactory region (high up in nasal cavity)
• Olfactory cells and cillia
• Central process - olfactory nerves
• Pass through the cribriform plate
• Olfactory bulb
• Olfactory tract
• Prepyriform cortex
• Amygdaloid nucleus where it reaches consciousness
94

43. DISORDERS OF SMELL
• Anosmia: total loss of smell
• Hyposmia: partial loss
• Parosmia: perversion of smell –
– Interprets the odour incorrectly
– Seen in
• Recovery phase of post influenzal
anosmia,
• Intracranial tumour
96