ANATOMY, BLOOD SUPPLY , RELATIONS

1. ANATOMY OF NOSE & PNS
FUNCTIONS OF NOSE & PNS
Dr. Ajay Manickam
Junior Resident
Dept of Otorhinolaryngology
R G Kar Medical College

2. EMBRYOLOGY
• Facial development takes place between 4 – 8 weeks of intra
uterine life
• Face develops from 5 facial swellingsthat surround the
Primitive mouth by the end of 4th week
Central unpaired frontonasal process
Pair of maxillary process
Pair of mandibular process

3. At 5th week thickening appear in fronto nasal
process called nasal placodes
At 6th week nasal placode invaginates to form
nasal pits
6th and 7th week maxillary process increase in size
to grow medially
They fuse with medial nasal process & then with
lateral nasal process
This separates nasal pits from stomadeum

4. Medial nasal process fuse with eachother to form inter
maxillary process
Which forms central bridge of nose and the central portion of
upper lip philtrum
Inter maxillary process grows backward to form nasal
septum
lateral nasal process enlarge to form alae, grow backward to
form lateral nasal wall, which show ant post elevation to form
turbinates.

5. • Maxillary process fuses with the lateral
nasal process
• The junction is marked by a groove called
nasolacrimal/ naso optic groove
• By 7th week groove invaginates into
mesenchyme to form nasolacrimal duct
• Canalization continues throughout
pregnancy and may not be complete till
after birth

7. Anatomy of nose
• Nose can be divided into external nose & nasal cavity
• External nose consists of

8. External nares
• Oval apertures on the inferior
aspect of external nose
• Held open by the alar cartilages
and septal cartilages
• Inferior nasal spine and adjacent
margins of maxillae

9. ANATOMY OF NOSE
• Nasal cavities are elongated wedge
shaped spaces with large inferior
base and narrow superior apex
• Ant apertures are the nares, open
onto inferior surface of nose
• Post apertures are the choanae,
which open into the nasopharynx

10. DIVISIONS OF NASAL CAVITY
• Nasal cavities
• Lateral wall of
nose
Conchae divide
nasal cavities into
four air channels
Conchae increase
surface area of
contact between
lateral wall and
respired air

11. Regions of Nasal Cavity
• Nasal vestibule
• Respiratory region
• Olfactory region

12. Skeletal framework of nasal cavities
• UNPAIRED- Ethmoid,Sphenoid,Frontal & Vomer
• PAIRED- Nasal,Maxillary,Palatine,Lacrimal & Inf conchae

13. Ethmoidal Bone
• Complex bone of skull
• Contributes to roof, lateral wall,medial wall
of nasal cavity and contains ethmoidal
cells

14. Ethmoidal bone
• Cuboidal in shape
• 2 ethmoidal labyrinths – united by cribriform
plate – separates nasal cavity from cranium
• 2nd sheet – perpendicular plate descends
vertically from cribriform plate
• Ethmoidal labyrinth 2 sheets
Lateral sheet – orbital plate
Medial sheet – upper part of lat wall of nose
• Irregular projection the uncinate process
• Articulates
Ant – nasal spine of frontal bone
Post – sphenoidal crest of sphenoid , vomer
Inf – ant – septal cartilage

15. Sphenoidal bone
• Closes the back of nasal cavity and
separates it from ant and middle
cranial fossa
• Lesser wing attached to body by two
roots between which lies optic canal
• Medial pterygoid plate forms the
lateral wall of post choana
• Inferomedian funnel shaped foramen
vidian canal
• Supero lateral foramen is foramen of
rotundum transmits maxillary nerve

16. Frontal bone
• Centre of frontal bone is a hiatus
that’s filled with cribriform plate of
ethmoid
• Either side of hiatus are aircells of
ant & post ethmoidal cells
• Lateral border of these aircells
articulate with lamina papyracea of
ethmoidal bone
• At the junction of these suture lines
lies ant and post ethmoidal
foramina
• Anteriorly midline frontal bone
elongated to form the nasal spine

17. Vomer
• It is located in the midsagittal line,
and articulates with thesphenoid,
the ethmoid, the left and
right palatine bones, and the left and
right maxillary bones.
• The vomer forms the posterior part
of the nasal septum, with the
anterior part formed by the ethmoid.

18. Nasal bone
• 2 small rectangular bones , forming bridge
of nose
• 2 surfaces and 4 borders
• External surface- covered by procerus and
nasalis muscle
• Internal surface concave side to side,
groove for ant ethmoidal nerve
• Superior border-frontal bone
• Inferior border = upper lateral cartilage
• Medial border –opposite nasal bone-part
of septum
• Lateral border-frontonasal process of
maxilla

19. Maxillary bone
• Forms base of framework on
which lat nasal wall is built
• Large opening in maxillary bone
is closed off by processes of
different bones
• Descending process - lacrimal
bone ant
• Uncinate process - ethmoidal
bone antinferiorly
• Maxillary process - inf turbinate
inferiorly
• Perpendicular plate of palatine
bone post

20. Maxillary Bone
• Fronto nasal process of
maxilla
• Medial surface of this process
has 2 crests
• Ethmoidal crest- ant part of
middle turbinate is attached
• Lower crest gives attachment
to inf turbinate
• Immediately below
frontonasal process groove-
canal for NLD
• Maxillary tuberosity- canal for
greater palatine vessels

21. Palatine Bone
• L shaped bone
• Perpendicular plate- ant border of plate
has maxillary process, inferiorly
continues with horizontal plate, superiorly
with maxilla by orbital process and
sphenoid by sphenoid process
• Horizontal plate- anteriorly articulates with
horizontal process of maxilla to form floor,
post free end
• Pyamidal process articulates with the
notch between two pterygoid plates

22. Lacrimal Bone
• Smallest and most fragile cranial bone
separates lacrimal fossa from nasal cavity
• Articulates anteriorly with frontonasal
process,
• Orbital surface has a crest, between two
crest is the lacrimal fossa containing sac
• Nasal surface of the lacrimal bone is
pneumatised by an anteriorly migrated
ethmoidal cell the agger nasi cell

23. Inferior conchal bone
• Separate scroll like bone
• 3 processes
• Anteriorly lacrimal process articulates
with descending process of lacrimal
bone assists in NLD
• Ethmoidal process- articulates with
ucinate process of ethmoid bone
• Maxillary process-forms part of inf
meatus

25. Floor Of Nasal Cavity
• Smooth, concave, much wider
than roof
• Consists of
1. soft tissues of ext nose
2. upper surface of palatine process
of maxilla and horizontal plate of
palatine bone, which together form
hard palate

26. Roof Of Nasal Cavity
• Its narrow, highest in the central
region, where it is formed by the
cribriform plate of the ethmoid bone
• Anterior to cribriform plate roof
slopes inferiorly to nares formed by
1.Nasal spine of frontal bone,nasal
bone
2.Septal cartilage and alar cartilage
• Posteriorly roof slopes into choana
and formed by
1.Ant surface of sphenoid bone
2.Ala of vomer
3.Vaginal process of medial plate of
pterygoid

27. Medial wall of
nose
• Mucosa covered surface of thin nasal
septum, separates right and left nasal cavities
• Nasal septum consists of
1.Septal nasal cartilage anteriorly
Posteriorly
1.Vomer
2.Perpendicular plate of ethmoid
• Small contribution
1.nasal bone
2.Nasal spine of frontal bone
3.Nasal crests of maxillary and palatine bones
4.Rostrum of sphenoid bone
5.Incisor crest of maxilla

28. Lateral wall of nose • Formed by bone,cartilage,soft
tissues
• Bony support for lateral wall of
nose is provided by
1.Ethmoidal labyrinth and uncinate
process
2.Perpendicular plate of palatine
bone
3.Pterygoid process of the
sphenoidal bone
4.Medial surfaces of lacrimal bone
5.Medial surface of maxillary bone
6.Inferior concha

29. Lateral wall of nose • Inferior,middle,superior conchae
extend medially across nasal
cavity spreading into four air
channels
• Lateral wall of middle meatus
elevates to form dome shaped
bulla ethmoidalis, middle
ethmoidal cells ,which expands
the medial wall of ethmoidal
labyrinth
• Inferior to ethmoidal bulla is
curved gutter semilunar hiatus, its
anterior end forms channel the
ethmoidal infundibulum, which
curves upward and continues as
the fronto nasal duct

30. Lateral wall of nose
• Naso lacrimal duct- under ant lip of
inferior concha
• Frontal sinus- frontonasal duct and
ethmoidal infundibulum into anterior
end of semilunar hiatus
• Ant ethmoidal cells- drain into
frontonasal duct or ethmoidal
infundibulum
• Middle ethmoidal cells open onto
ethmoidal bulla
• Posterior ethmoidal cells open onto
lat wall of superior nasal meatus
• Maxillary sinus open into semilunar
hiatus

31. Choanae
• Choanae are rigid openings completely surrounded by bones
between nasal cavity and the nasopharynx
• Margins formed by
1.Post border of horizontal plate of palatine bone
2.Medial plate of pterygoid process
3.Medially by post border of vomer
• Roof formed by
1.Ant by ala of vomer
2.Post by body of sphenoid

32. Gateways of nasal cavity
• Cribriform plate
• Sphenopalatine foramen
• Incisive canal
• Small foramina in the lateral wall

33. Vessels
• ECA- 1.Sphenopalatine artery
2.Greater palatine artery
3.Superior labial artery
4.Lateral nasal artery
• ICA- Anterior and Posterior ethmoidal
arteries

34. Blood supply
• Spheno palatine.a terminal br of maxillary.a
Post lat nasal br
Post septal br
• Greater palatine artery br of maxillary.a
• Sup labial & lat nasal artery br of facial.a
• Post ethmoidal & ant ethmoidal.a br of ophthalmic.a

35. Venous drainage
• Veins pass with branches
that ultimately originate
from maxillary artery, drain
into pterygoid plexus of
veins
• Veins from anterior region
of nasal cavity join the
facial vein
• Veins accompanying ant
and post ethmoidal arteries
tributaries of superior
ophthalmic vein, largest
emmissary vein drain into
cavernous sinus

36. Innervation
• Olfactory nerve
• Branches of ophthalmic and maxillary nerves for general
sensation
• Parasympathetic
• Sympathetic

37. • V1
Ant & post ethmoidal nerve
• V2
Post sup lat nasal n
Post sup medial nasal n
Nasopalatine n
Post inferior nasal n
• Parasympathetic - secreto motor innervation of glands of
mucosa of nasal cavity & PNS
Preganglionic – greater petrosal br of facial n
Post ganglionic – join br of maxillary n
• Sympathetic – regulates blood flow
preganglionic – sup cervical sympathetic ganglion
Post ganglionic – deep petrosal n join greater petrosal n

38. Blood & nerve supply of external
nose
• External nose

40. Para nasal air
sinuses
• At birth the volume of cranial vault is
7 times that of facial skeleton
• This ratio decreases during infancy
and childhood, as a result of growth
of 4 pairs of PNS& development of
teeth
• Sinuses develop from invaginations
of nasal cavity that extend into the
surrounding bone
• Maxillary and ethmoidal sinus
develop in utero during 3rd and 5th
fetal months

41. Embryology PNS
• With eruption of deciduous teeth, maxillary sinus enlarges to
become 3 times longer, 5 times greater in height & width
• Ethmoidal sinus are small before the age of 2 years then grow
rapidly 6-8 years, but donot complete the growth until puberty
• Around the 2nd year the most anterior ethmoidal cell grow into
the frontal bone to form frontal sinus
• Frontal sinuses are visible in x ray from 7th year
• Most posterior ethmoidal air cell grows into sphenoid bone to
form sphenoidal sinus

42. Frontal Sinus
• Most superior , triangular in shape
• Base of each triangle is oriented vertically in the bone, at the
midline above the bridge of nose apex is approximately 1/3rd
way along the upper margin of orbit
• Drainage-middle meatus
• Nerve- supra orbital nerve from ophthalmic nerve
• Blood supply- ant ethmoidal artery branches

43. Ethmoidal air cells
• 9-10th week of gestation, 6-7 folds appear in
lat wall of nasal capsule of foetus
• Over next weeks folds fuse into 3-4
remaining crests with ascending anterior,
and a posterior descending portion
• Ethmoidal air cells are divided into,
anterior,middle posterior
• Anterior- ethmoidal infundibulum
• Posterior- lat wall of sup nasal meatus
• Middle- ethmoidal bulla
• Nerve- ant&post ethmoidal branches of
nasociliary merve from ophthalmic nerve 7
maxillary nerve
• Blood- ant & post etmoidal arteries

44. Maxillary sinuses
• First sinus to appear
• Largest of all, pyramidal in
shape
• Medial wall or base of
maxillary sinus formed by
maxilla and by parts of inf
concha, palatine bone
• Roof = related orbit
• Anterolateral surface= roots of
upper molar and premolar
teeth
• Posterior wall= infra temporal
fossa
• Nerve- maxillary nerve-infra
orbital & alveolar br
• Blood- maxillary a- infra orbital
& sup alveolar br

45. Sphenoidal sinuses • Within body of sphenoid
• Opens into roof of nasal cavity
via apertures on post wall of
spheno ethmoidal recess
• Related above- pituitary gland
&optic chiasm
laterally – cavernous sinus
below & in front – nasal cavities
• Nerve-
post ethmoidal br ophthalmic N
maxillary nerve
• Blood- pharyngeal br maxillary
artery

47. Endoscopic anatomy
• 1st pass- endoscope is passed
along floor of nasal cavity
between inf turbinate & septum
• Structures studied are
1.nasal septum
2.Inf turbinate
3.Post choana
4.Post wall & roof of nasopharynx
5.Eustachian tube opening
6.Fossa of rosenmuller
7.Opening of NLD- guarded by
hasner’s valve

48. Endoscopic anatomy
• 2nd pass
• Scope passed along floor upto post
choana, moved upward & medial to
middle turbinatealong the roof of post
choana and anterior surface of
sphenoid
• Structures seen
1.Superior turbinate and meatus
2.Sphenoethmoidal recess
3.Sphenoid ostium
4.Below ostium woodruff plexus

49. Endoscopic anatomy
• 3rd pass- examine contents of middle
meatus- by gently retracting middle
turbinate by freer’s elevator
• Structures seen are
1.Attachment of middle turbinate to cribriform
plate
2.Agger nasi cell
3.Uncinate process
4.Lamina papyracea
5.Accessory ostium

50. Anatomical variations of middle
turbinate
• Ballooned out air cell enclosed in it, from
frontal recess, agger nasi cell, ant
ethmoids, such a case middle turbinate is
called concha bullosa
• Vertical lamella may be pneumatized to
form intralamellar cell of grunwald
• May have paradoxical curve bending
laterally
• Bifid
• May attach to lat wall of maxillary sinus
• Lower part of normally curved middle
turbinate may curve far laterally to produce
a concavity within it called turbinate sinus

51. Histology
• Nasal septum
• Mucous membrane is
predominantly respiratory
with a small area of
olfactory epithelium,
adjacent to cribriform plate
• Composed of ciliated &
nonciliated
pseudostratified columnar
cells,basal pluripotential
stem cells & goblet cells
• Olfactory epithelium is
composed of receptor cells,
supporting cells with
microvilli & basal stem cells,
confering the capacity of
regeneration

52. Histology
• Lateral wall of nose
• Respiratory ciliated columnar epithelium, small variable
area superiorly of olfactory epithelium
• Areas of squamous metaplasia are often found on the lateral
wall, particularly in areas subject to greatest airflow

53. Histology
• Frontal sinus - respiratory
epithelium small number of goblet
cells, sero mucinous glands
• Maxillary sinus - ciliated columnar
epithelium with highest density of
goblet cells seromucinous glands
are infrequent
• Sphenoid sinus & ethmoid sinus –
respiratory epithelium is same
goblet cell population with least
sero mucinous glands

55. Functions of Nose and PNS
1.Respiration
• Heat exchange
• Humidification
• Filtration
• Nasal resistance
• Nasal fluids & ciliary functions
• Nasal neurovascular reflex
• Voice modification
2. Olfaction
• Two neurone peripheral pathway
• Trigeminal input
• Olfaction

56. Heat exchange
• Temperature of inspired air vary from -50 –
50 degree C.
• By the process of thermoregulation, latent
heat of evaporation, direction of flow of
blood, heat exchange occurs
• Gas in the nose, arterial blood 2 fluids, that
are in thermal, but not with direct contact

57. Humidification
• Vaporization cools the surface and 10% body heat is lost this way
• Inspiration
• Energy required for 2 function raising temperature of inspired air, latent
heat of evaporation
• Despite variation in temperature of inspired air, air in post nasal space is
31degree C , 95% saturated
• Expiration
• Expired air at back of nose is slightly below body core temperature
• As temperature drops along the nose , some water condenses to mucosa
• Water production
• Water comes from serous glands
• Capillary leakage occurs during inflamation- additional water comes from
expiredair, NLD, oral cavity

58. Filtration
• Airflow pattern
• Inspiration
• directed upwards and backwards mainly
over ant part of inferior turbinate
• Then splits to two below and over middle
turbinate, rejoining post choana
• Expiration
• lasts longer
• More turbulent

59. Nasal resistance
• Difference exist between races
• Nose accounts for upto half the total airway resistance
• Resistance made of
• 1. bone,cartilage,attached muscles
• 2.variable , the mucosa
• Nasal resistance is high in infants

60. Nasal fluids and ciliary functions
• Nasal secretions 2 elements mucus &
water
• Composition of mucus
• Water & ions
• Glycoproteins
• Enzymes
• Circulatory proteins
• Proteins
• Imunoglobulins
• cells

61. Nasal immune system
• Surface properties
Mechanical
Physical characteristics of mucus
• Innate immunity
Bacteriocidal activity in mucus
Proteins
cellular component
• Acquired immunity
Ig A, IgM, IgE & IgG
Lymphocytes
Primed macrophages
• Distant sites
Adenoids , LN, Spleen

62. Reflexes
• Axon reflexes
• Substance p vasodilator transmits anti dromic reflex
• Initiated by mechanical irritation or histamine release
• This amplifies the response
• Nasopulmonary reflexes
• Increasing airflow through one nose cause increased
ventilation on the homolateral lung
• Blowing air through the nose causes bronchiole muscle to
relax on the same side and increases respiratory activity

63. Reflexes from nasal stimuli
• Chemical, temperature change and physical stimuli cause
widespread cardiovascular and respiratory responses
• Response ranges from sneezing to cardio respiratory arrest
• Sneezing- change in respiratory rate with closure of larynx and
a variable cardiovascular response occurs
• Sensory stimulation accompanied by lower cardiac output
• Modification of submersion reflex

64. Nose and the voice
• Nose adds quality by allowing air to
escape
• Rhinolalaia clausa too little air escapes
• Rhinolalia aperta too much escapes

65. Olfaction
• Stimulus – odours react with lipid
bilayer of receptor cells at specific
sites, causes k+ & cl – to flow out
and depolarize cell
• Receptors – G protein coupled
receptorsreact with specific adenyl
cyclase
• Discrimination – man prefers to
detect pleasantness of an odour

66. Olfaction

67. Trigeminal input
• Most smell independent of trigeminal
nerve, but at high concentrations irritation
occurs
• Patient who are anosmic notice only
sweet,sour,salt & bitter & irritation.
• Irritation contributes to nature of smell

68. Olfaction areas of behaviour
• Helps in recognizing food types & initiation
of digestion
• Sexual behaviour
• Territorial markings
• Perception decreases with age and
neurodegenerative diseases
• Olfaction is fully developed at birth, but
recognition and learning come late,
probably after the age of 2 years

69. Physiological functions of sinuses
• Vocal resonance
• Dimnuition of auditory feedback
• Air conditioning
• Pressure damper
• Reduction of skull weight
• Floatation of skull in water
• Mechanical rigidity
• Heat insultation