anatomy of nose

2.  External Nose
 Internal Nose
 Blood Supply
 Nerve Supply
 Lymphatic Drainage
 PNS
 Embryology

3.  Triangular pyramidal structure
 Bony (upper 1/3rd) and Cartilaginous (lower 2/3rd
)
 Root of nose – upper angle of nose where it is
continous with forehead.
 Base of nose – triangular, directed downwards
 Tip of nose – free angle of nose below
 Dorsum of nose – lower cartilaginous part
connected to tip
 Bridge of nose – upper bony part of dorsum
connected to root. It is a junction between 2
nasal bones
 Glabella – point between root of nose and
forehead

5.  Upper 1/3rd
 Paired nasal bones
 Paired frontal process of maxilla
 Nasal process of frontal bones
 Nasal bones articulate
 Sup – nasal process of frontal bone
 Inf – upper lateral cartilage
 Lat – frontal process of maxilla
 Med – opp nasal bone
 Nasion – upper point where they meet
 Rhinion – lower point where they meet

6.  Paired upper lateral cartilages
 Paired lower lateral cartilages (alar)
 Sesamoid cartilage (lesser alar)
 Septal cartilage (ant sup part)
 Hyaline cartilage
 Bone and cartilage connected to each other
by periosteum and perichondrium which is
continous

8.  Upper lateral cartilages
 Triangular in shape
 Form dorsum of nose
 Middle 1/3rd
 Lower lateral cartilages (alar)
 Maintain projection and shape of tip
 Lower 1/3rd
 Parts
 Slender medial crus – 2 in midline form columella
 Wider lateral crus – form ala of nose each side
 Projection between two – form tip of nose

9.  Sesamoid cartilage (lesser alar)
 Minor
 2 or more in number
 Present between upper and lower nasal cartilage
 External Nasal Skin
 Continous with skin of vestibule and columella
 Thin and freely mobile – nasal bones and upper
lateral cartilage
 Thick and adherent – alar cartilage, contains
sebaceous glands – hypertrophy (rhinophyma)

10.  Facial muscles bring about movement of nose
 Procerus
 Nasalis (transverse and alar)
 Levator labii superioris alaeque nasi
 Depressor septi
 Ant and post dilator nares
 Arise from fascia and inserted into skin
 Facial N

12.  Right and left by nasal septum
 Communicates with external (ant nares),
nasopharynx (choanae), sinuses (ostium)
 Each nasal cavity 5-7 cm length, 5 cm height,
1.5 cm transversely at floor, 1-2 mm at roof
 Parts
 Skin lined – Vestibule
 Mucosa lined – cavity proper
 Nasal cavity proper – medial wall, lateral
wall, roof, floor

13.  Ant inf part of nasal cavity, entrance
 Lined by skin
 Contains hairs (vibrissae), hair follicles,
sebaceous glands, sweat glands
 Limen nasi – sup margin of lower lateral
cartilage, separates vestibule from nasal
mucosa. Upper limit of nasal vestibule
 Part of dangerous area of face – triangular
area extending from nasion to angle of
mouth (includes external nose and upper lip)
– without valve venous drainage – lead to CST

14.  Narrowest part of nasal cavity
 Triangular shaped
 Area of high resistance, mild narrowing
causes nasal obstruction
 Regulates air flow
 Medially – cartilaginous septum, caudally –
floor, laterally – ant end of inf turbinate,
lower border of upper lateral cartilage
 Columella – between two nasal vestibules,
formed by medial crusa of alar cart, forms
caudal end of nasal septum

15.  Framework – Floor, Roof, Medial wall and
lateral wall
 Floor
 Made up of hard palate
 Palatine process of maxilla (ant 3/4th)
 Horizontal process of palatine bones (post
1/4th)
 5cm long, 1.25 cm wide

16.  Highest part of nasal cavity
 Ant sloping part – nasal bones
 Post sloping part – body of sphenoid
 Middle horizontal part – cribriform plate of
ethmoid
 Part of olfactory area
 Olfactory area
 Bounded lat by sup turbinate, med by septum
and sup by cribriform plate
 Dangerous area as olfactory nerve fibres from
this area pass through cribriform plate to ant
cranial fossa and carry infection, ass with CSF
rhinorrhoea

17.  Bony and cartilaginous framework lined by
mucoperiosteum and mucoperichondrium
 Columellar septum – covered by skin, medial crus
 Membranous septum – b/w columella and septum
proper, no bone or cartilage, double layer of skin
 Septum proper
 Cartilaginous part – large quadrangular cartilage
with contributions from upper and lower lateral
cartilage
 Septal cartilage provides support to tip and
dorsum of nose

18.  Bony part
 Perpendicular plate of ethmoid – post superior
part
 Vomer – post inferior part
 Maxillary crest – inf most part
 Palatine crest
 Small contributions from nasal spine of frontal
bone, rostrum of sphenoid, ant nasal spine of
maxilla
 Jacobson’s organ – concerned with smell in
lower animals, vestigeal in adult humans,
defined in foetus as blind tubular pouch 2-6 mm
long

20.  Irregular
 Atrium – lies b/w vestibule and concha in the
lateral wall
 Covered by respiratory epithelium
 Formed by various bones
 Main area for drainage of sinus secretions
 Formed by medial wall of maxilla, middle and
sup concha (ethmoid bone), inf concha, medial
pterygoid process of sphenoid, nasal bones,
perpendicular plate of palatine bones
 Has scroll/shelf shaped ridges/ bony horizontal
elevations called turbinates (sup/middle/inf)
and beneath and lateral to them depressions
called meatus (sup/middle/inf)

21.  Superior turbinate
 Smallest
 Part of ethmoid bone
 The area above it and its medial part lined
by olfactory epithelium
 Ostium of sphenoid sinus lies medial to it
 Supreme turbinate
 60% of cases, U/L or B/L
 Small ridge above sup turbinate

22.  Middle turbinate
 Part of ethmoid bone
 Formed by middle concha
 Has basal lamina – joins lamina papyracea
 Ascending limb – joins cribriform plate
 Bony lamella (basal or ground) – attached to lateral wall
 Concha bullosa – pneumatized middle turbinate by
ethmoidal air cells
 Paradoxically curved – narrowed middle meatus
 Post end – sphenopalatine foramen (gap b/w fusion of
sphenoid, palatine and ethmoidal bones)


23.  Inferior turbinate
 Largest
 Separate bone
 Composed of inf concha
 Submucosa – contains rich cavernous venous plexus
 Superior meatus
 Smallest, lies beneath sup concha
 Opening for post ethmoid air cells (1-5)
 Sphenoethmoidal recess
 Triangular area above sup turbinate
 Sphenoidal sinus opens here

24.  Middle meatus
 Lies below middle concha
 Major structure jere forms osteo meatal complex
 Frontal, maxillary, ant ethmoidal sinus drain
here
 Inferior meatus
 Largest
 Present along the whole length of lateral wall
 NLD opens in the ant part, under genu of inf
turbinate, opening guarded by a valve – hasner’s
valve (plica lacrimalis)

26.  Skin
 Stratified squamous epithelium covers vestibule
 Olfactory epithelium
 Upper 1/3rd of lateral wall till sup concha, roof, nasal
septum
 Mucous membrane – pale (yellowish) in colour
 Respiratory epithelium
 Lower 2/3rd of nasal cavity
 Thickest over concha, thick over septum
 Thin over meatus and floor
 Pink in colour, pseudostratified ciliated columnar
epithelium

27.  Arterial supply
 ICA and ECA
 ECA – maxillary artery (sphenopalatine, greater
palatine), facial artery (sup labial)
 ICA – ophthalmic artery (ant and post ethmoidal)
 Lateral wall
 Main artery – sphenopalatine artery – all meatus
and turbinates
 Roof and sup part – ant ethmoidal artery
 Alae nasi – sup labial artery

28.  Medial wall (septum)
 Ant sup part – ant ethmoidal artery
 Ant inf part – sphenopalatine artery – main
artery to septum, also called artery of epistaxis
 Keisselbach’s plexus (little’s area)
 Anastomotic plexus b/w sphenopalatine, greater
palatine, sup labial and ant ethmoidal artery
 Frequent site for bleeding (90%, ant epistaxis)
 Site for origin of bleeding polyposis
(haemangioma of nose)

30.  Ant part – ant facial vein and ophthalmic vein
 Middle part – pterygoid venous plexus
 Post part – pharyngeal plexus of veins
 Cavernous plexus – beneath the middle meatus formed of
sphenopalatine vein, ophthalmic vein, sup saggital sinus
 Retrocolumellar vein – just behind the columella,
common site for venous bleeding
 Woodruff’s plexus – site for venous bleed inf to post end
of inferior turbinate
 Arterial bleed post to middle turbinate
 Site for post epistaxis, maxillary sinus ostia dividing line

32.  Erectile tissue
 Subepithelial venous plexus
 Seen mainly in inf turbinate, post part of
middle turbinate, septum
 Controlled by ANS – maintains congestion and
decongestion of turbinates

33.  Trigeminal nerve – sensory supply
 Ophthalmic nerve – ant ethmoidal nerve – ant
and sup part of nasal cavity – blocked by placing
pledgets high up
 Maxillary nerve – sphenopalatine branch – post
2/3rd of nasal cavity – blocked by placing
pledgets post extension of middle meatus
 Infra orbital nerve – vestibule of nose
 Facial nerve – motor supply
 Olfactory nerves – 20 in number - smell

35.  Secretomotor supply – vidian nerve (nerve of
pterygoid canal)
 Formed by
 Deep petrosal nerve – sympathetic plexus
around ICA
 Greater sup petrosal nerve – parasympathetic
supply to nasal glands and controls nasal
secretions

36.  Submental lymph nodes (anterior part and
external nose)
 Retropharyngeal ln (post part)
 Upper deep cervical ln (post part)
 Preauricular ln