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Anatomy of Nose &
Paranasal Sinuses
Dr. Vishal Sharma
Development of
nose
• Face develops from 5 projections: frontonasal
process (ectoderm over forebrain) + 2 maxillary
processes + 2 mandibular processes (1st arch)
• An ectodermal olfactory placode divides frontonasal process into medial nasal & lateral nasal
process, which give rise to external nasal skeleton
• Olfactory placode deepens into olfactory pit & later
olfactory sac which forms nasal cavities
• Nasal septum develops from mesodermal tectoseptal expansion from Rathke’s pouch
External Framework
External Framework
• Nasal Bone
• Frontal Process of Maxilla
• Upper Lateral Nasal Cartilage
• Lower Lateral Nasal (Alar) Cartilage
• Septal Cartilage
• Lesser Alar (Sesamoid) Cartilages
Internal Nose
• Openings: Anterior nares & posterior
nares (Choanae).
• Vestibule of nose: lined by skin
• Nasal cavity proper:
 Lateral Wall
 Medial Wall (Septum)
 Roof
 Floor
Nasal Septum
Nasal Septum
Nasal Septum
1. Septal cartilage
7. Medial alar crus
2. Ethmoid plate
8. Upper lateral cartilage
3. Vomer
9. Nasal bone crest
4. Palatine crest
10. Frontal spine
5. Maxillary crest
11. Sphenoid rostrum
6. Vomeronasal
12. Membranous septum
cartilage
Lateral Nasal Wall
 3 - 4 bony conchae covered with mucosa
to form turbinates. Space below & lateral
to turbinate is called meatus.
 Middle meatus contains a round bulla
ethmoidalis separated from uncinate
process by hiatus semilunaris that leads
to a funnel shaped ethmoidal infundibulum.
Meatal Drainage
1. Inferior meatus: Nasolacrimal duct ( guarded at its end
by a mucosal valve called HASNER’s valve )
2. Middle meatus:
a. Frontal
b. Anterior ethmoid
c. Maxillary (natural + accessory ostia)
3. Superior meatus: Posterior ethmoid
4. Spheno-ethmoidal recess: Sphenoid
Ostio-meatal Complex
Ostio-meatal Complex
Complex micro-architectural pathway in ethmoid
labyrinth that drains anterior group of paranasal
sinuses. Consists of: frontal recess + ethmoid
infundibulum + hiatus semilunaris + uncinate
process + bulla ethmoidalis + middle meatus.
O.M.C. pathology leads to infection of all anterior
paranasal sinuses (Naumann).
Variants in O.M.C.
1. Concha bullosa (pneumatized M.T.)
2. Paradoxically curved middle turbinate
3. Medially turned uncinate process
4. Large bulla ethmoidalis
5. Haller’s cell in orbital floor
6. Agger nasi cell anterior to M.T.
7. Onodi Cell with dehiscent Optic Nerve
8. Mucosal pathology
Concha bullosa
Concha bullosa
Paradoxically curved M.T.
Paradoxically curved M.T.
Medialized Uncinate Process
Large bulla ethmoidalis
Haller cell
Agger nasi cell
Onodi cell with dehiscent optic nv
Mucosal disease
Blood Supply
1. Sphenopalatine artery (main artery)
2. Greater palatine artery
3. Superior labial artery
4. Anterior Ethmoidal artery
5. Posterior Ethmoidal artery
1, 2, 3 & 4 form Kiesselbach’s plexus over
Little’s area on anterior septum
Venous drainage
Ethmoidal veins:  ophthalmic veins
 cavernous sinus
Sphenopalatine vein:  pterygoid plexus
 maxillary vein
Woodruff’s venous plexus: present on lateral wall
near posterior end of middle turbinate
Retro-columellar vein: behind columella
Sensory Nerve Supply
• Long & short Nasopalatine nerves
• Greater palatine nerve
• Infra-orbital nerve branches
• Anterior ethmoidal nerve
• Olfactory nerve
Autonomic Nerve Supply
• Deep petrosal nerve (sympathetic) + greater
superficial petrosal nerve (para-sympathetic) 
vidian nerve  pterygo-palatine ganglion 
nasal glands
• Sympathetic stimulation  vasoconstriction +
ed nasal secretions
• Para-sympathetic stimulation  vasodilatation
+ ed nasal secretions
Lining Epithelium
• Skin: over nasal vestibule
• Olfactory epithelium: upper 1/3rd of nasal cavity
above superior turbinate
• Respiratory epithelium (pseudo-stratified
ciliated columnar): rest of nasal cavity +
paranasal sinus
Lining Epithelium
Lymphatic Drainage
1. External nose & anterior nasal cavity 
submandibular lymph nodes
2. Remaining nasal cavity 
upper deep cervical lymph nodes
3. Nasal roof (dangerous area of nose) 
subarachnoid space along olfactory nv
4. P.N.S.  retropharyngeal & J.D. node
Paranasal Sinuses
• Anterior group:
 frontal
 anterior ethmoidal
 maxillary
• Posterior group:
 posterior ethmoidal
 sphenoid
Development of P.N.S.
Appear
first
First X-ray
appearance
Reach adult
size by
Maxillary
At birth
4 mth
15 yr
Ethmoidal
At birth
1yr
12 yr
Sphenoid
2 yr
4 yr
18 yr
Frontal
4 yr
6 yr
15 yr
Sphenoid Sinus Relations
Muco-ciliary blanket
• Goblet cells in nasal mucosa secrete a
mucous blanket; moved backwards like a
conveyer belt into nasopharynx.
• Consists of:
 Superficial mucous or gel layer
 Deep serous or sol layer
Muco-ciliary blanket
Muco-ciliary blanket
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