The document discusses the anatomy of the nose and paranasal sinuses. It describes the structures of the external nose including the vestibule, septum, lateral wall, roof and floor. It then covers the four main paranasal sinuses - maxillary, ethmoid, frontal, and sphenoid sinuses - describing their locations, drainage pathways, and key relationships to surrounding structures. Finally, it discusses the blood supply, lymphatic drainage and functions of the nasal cavity and paranasal sinuses.
2. Vestibule
Examination :- By Lifting the tip of the nose.
Dilated Passage way leading from external nose to
the nasal fossa.
Demarcated by Limen Nasi
Superiorly lined by skin, contains hairs, sebaceous
gland and sweat glands
3. Furunculosis of Nose
Skin loosely attached at the dorsun
and lateral sides but firmly attached
at tip and the Alar cartilage – it
contains sebaceous gland –
Rhinophyma
4. Supporting framework of external
nose
Lower lateral cartilage has horse shoe shape,
lateral cross is broad and strong forms alae,
medial portion is weak and extends partly along
the free caudal end of cartilaginous septum and
partly within the membranous columella.
5. Muscles of the external Nose
Nasal cavity has – medial wall,
lateral wall, roof and floor.
Nasal Septum (Medial wall)
Septum has 3 parts
Bony
Cartilagenous
Membranous (Columella)
7. Roof
Upper and lower lateral cartilage.
Nasal bones
Nasal process of frontal bones
body of ethmoid
body of sphenoid
Cribiform plate – Major part of roof.
Transmits the filament of the olfactory nerve, which
distributes in the mucous membrane covering the
upper part of the nose
2-4 cm2 area
9. Turbinates
Inferior turbinates – largest, separate bones,
bones of the inferior turbinate is deeply pitted,
cellular, surface of the turbinate is perforated by
blood vessels.
(Turbinectomy - Turbinoplasty)
10. Inferior Meatus
– Nasolacrimal duct (Hasner's Valve)
Middle turbinate
Smaller then inferior turbinate
Stroma of the middle turbinate contains many
gland
Key structure in FESS
11. Variations of middle turbinate
Concha bullosa
Paradoxical MT
Double Middle turbinate
Polypoidal change in MT
12. Middle Meatus
Osteomeatal complex
All the anterior group of sinuses (Maxillary,
anterior ethmoid, frontal sinus) drains.
Deep crescentric groove hidden by the MT is
infundibulum
Fissure leading from MT into infundibulum is
hiatus semilunaris
Ethmoidal bulla – bulge from anterior ethmoid
cells.
13. Superior turbinate – not visualized by anterior
rhinoscopy or nasal endoscopy.
Smallest of all the turbinates
Landmark for the ostium of sphenoid sinus
14. Superior Meatus
Posterior ethmoid drains
Supreme turbinate occasionally present
Sphenoethmoidal recess – above and behind the
superior turbinate – sphenoid sinus opens
16. Maxillary Sinus (Antrum of
Highmore)
Largests of all the sinuses
Presence since birth
At birth floor of maxillary sinuses is above
the nasal floor, descends continuously until
it reaches the age of 8 yrs – Same level
17. At the age of 18yrs floor of maxillary sinus
is below the floor of nasal cavity.
Shape- Pyramidal, base towards the nasal
cavity, apex towards the zygoma.
Natural osteum of maxillary sinus opens in
middle meatus.
Anti-gravity drainage, cilliary movement is
towards the natural osteum in middle
meatus.
Inferior meatal anstrostomy – non
physiological
18. Relation
Roof – floor of orbit – infraorbital nerve
Blow out # - entrapment of inferior rectus
muscles
Medial wall – lateral wall of nose
Anterolateral wall – bone undernith cheek
Posterior wall – separates its from pterygo
palatine fosa.
Floor – upper alveolus and hard palate
2nd premolar and 1st & 2nd molar in relation
with maxillary antrum
Chronic Maxillary Sinusitis
19. Sphenoid Sinus
Small before 3yrs but fully develop by 12 – 15
yrs.
Situated within the sphenoid bone, variable in
size and shape
Separated from each other by bony septum.
Communicates with superior meatus by small
aperture which opens into spheno ethmoidal
rescess. Size varies – 0.5 – 4 mm
Anti-gravity drainage
21. Ethmoid Sinus
Ethmoid cells lies in either side just lateral to the
superior 1 half of the nasal cavity medial to bony
orbit. Ethmoid bones have horizontal plates and
vertical plates that are at right angle with each other.
Vertical portion has superior part called crista galli and
inferior part called perpendicular plate of ethmoid.
The horizontal plate is comprised of medial portion –
cribiform plate and lateral portion that forms the roof
of ethmoid.
22. Contd…..
Two groups of ethmoid air cells
anterior group
Posterior group
Separated by basal laella
Anterior group drains to middle
meatus
Posterior group drains to superior
meatus
Clinically – attachment of middle
turbinate to lateral nasal wall marks the
23. Anterior group lies infront and posterior
group lies above and behind
The two group differ in size, usually the
posterior ethmoidal cells are fewer in
number 3-7 and larger in size.
Contd…..
24. Mucoele in children
It is relatively well developed at
birth.
It has a close relation with orbit
(Lamina papyracea) and
anterior cranial fossa, infection
may spread easily to these
structure.
During FESS in inexperience
hand there is a chance of injury
to these area.
25. Frontal Sinus
Absent at birth, rudimentary till the age of 7
yrs.
Rarely identical, varies greatly in size and
shape.
Bony septa may divide sinus into one or
more compartment.
Occasionally it may not phenumatize at all.
It drains to middle meatus through fronto-
nasal duct.
The duct is tortuous bony passage runs
through the anterior ethmoid sinus down to
26. Contd…..
It is because of its tortuosity
and length the duct gets block
to form frontal mucoele.
Frontal sinus has anterior
table, posterior table (which
also forms the roof) and floor
Relation – posteriorly –frontal
lobe
Inferiorly – roof of ethmoid
medially and roof of orbit
laterally.
Inferiorly in the floor the
fronto-nasal duct, its anterior
27. Nasal Mucus membrane
Nasal cavity, nasopharynx and sinuses are
lined by pseudo stratified columnar ciliated
epithelium (Respiratory type)
The vestibula area of nasal cavity is lined
by cuboidal epithelium
Area above the superior turbinate is lined
by olfactory epithelim – it is brownish in
color, confined to cribiform plate, it extends
medially to septum and laterally to superior
turbinate. Olfactory nerve may get damage
by head injury – loss of smell (anosmia)
28. Nerve supply
Nose and paranasal sinuses has
Sensory
autonomic
specific sensory (olfactory)
Sensory: Through the ophthalmic and
maxillary division 5th nerve
Autonomic: the secretory gland of the nasal
mucosa are under the control of autonomic
nervous system via the nerve of pterygoid
canal (vidian nerve), which contains both
sympathetic fibres and para sympathetic
fibres.
29. Contd……
Sympathetic stimulation constrict the mucosal
vessel, reduces the size of turbinate –
enlarging airway. Parasympathetic stimulation
reverse the condition.
Olfactory nerve fibre
The bipolar olfactory cells that lies in the
olfactory epithelium are the first order of
neurons. Axons from these combined to form
about 20 olfactory nerves.
These nerves pass through the cribiform plate
to relay at the olfactory bulb.
The neurons from the bulb run in the olfactory
tract to the 2nd olfactory centre in the frontal
30. Blood Supply of Nasal cavity
Recurrent posterior epistaxis –
sphenopalatine artery ligation.
Venous drainage –
Venous drainage of nose and paranasal
sinuses is to the ophthalmic vein, facial vein
and to the pterygoid and pharyngeal plexus.
Cavernous sinus thrombophlebitis
31. Lymphatic drainage
The anterior part of the nose and the sinuses
drains to submandibular lymphnode and to
deep cervical chain.
Posterior part of nose and posterior sinuses
drain to retropharyngeal lymph node.
Functions of paranasal sinuses
air conditioning
pressure damping
reduction of skull weight
heat insulation
increase the olfactory area
vocal resonance
mucus production