3. Nasal cavityNasal cavity
• Extends from nares as far back asExtends from nares as far back as
posterior nasal apertures or CHOANAE.posterior nasal apertures or CHOANAE.
• Between posterior border of medialBetween posterior border of medial
pterygoid plates of spehnoid n vomer.pterygoid plates of spehnoid n vomer.
• Here nasal cavity communicates withHere nasal cavity communicates with
nasopharynx.nasopharynx.

4. Lateral wallLateral wall
• Mainly formed by maxilla.Mainly formed by maxilla.
• Perpendicular plate of palatine bone does soPerpendicular plate of palatine bone does so
posteriorly n beyond this medial pterygoid plateposteriorly n beyond this medial pterygoid plate
with which articulates.with which articulates.
• Extends as far back as choanae.Extends as far back as choanae.
• Sphenopalatine foramen present at the top ofSphenopalatine foramen present at the top of
perpendicular plate .perpendicular plate .
• Provides a portal for communication betweenProvides a portal for communication between
nasal cavity n pterygopalatine fossa.nasal cavity n pterygopalatine fossa.

5. The labyrinth
• Lateral mass) of ethmoid bone.
• Occupies much of upper part of maxillary hiatus.
• The inferior concha lies below it.
• Articulating anteriorly with maxilla n post: with
palatine bone.
• Superior n middle conchae are part of ethmoidal
labyrinth.
• These conchae called also as turbinates=are
curved shelves of bone projects into nasal cavity
from their attachments on lateral wall.

8. • Each enloses a passage the Meatus under
its concave inferior surface.
• The Atrium= A depression in front of middle
concha,leads upwards into meatus behind it.
• Atrium bounded anterioly n above by
ridge=THE AGAR NASI.
• This may contain few ethmoidal air cells.

10. Anteriosuperior part of lateral wall
• Formed by nasal bone n frontal process of
maxilla.
• Lacrimal bone articulate with later n with
inferior concha.
• Enclosing between them canal for
nasolacrimal duct.
• Opens into upper part of inferior meatus
about 1cm behind anterior end of concha.

12. Medial wall or nasal septum.
• Consist of bone and cartilage.
• The traingular vomer,articulating above with
sphenoid body .
• Forms posterior border of septum.
• Inferiorly it is slotted into a grooved ridge on hard
palate n extends beyond incisive canal.
• Vomer is grooved on each side by nasopalatine
nerves.
• Perpendicular plate of ethmoid articulates with
upper margin of vomer but not whole length.

15. Septal cartilage
• Unossified part of ethmoid’s perpendicular
plate forms anterosuperior part of septum.
• Inferiorly slotted into a bony groove at its
vomerine n amxillary articlulations.
• Anteriorinferior corner of septum is mobile.
• Formed by medial crura of paired major
alar cartilages.

16. THE FLOOR
• Upper surface of hard palate.
• Which forms roof of mouth n comprises
the palatal process of maxilla n horizontal
plate of palatine bone.
• Either side of septum anteriorly a small
opening leads to an incisive canal
traversed by nasopalatine nerve n greater
palatine artery.
• Central part of roof is cribriform plate of
the ethmoid.

17. Face Bones (Cont.)Face Bones (Cont.)
• Inferior Nasal Conchae (2)Inferior Nasal Conchae (2)
– Located on each side ofLocated on each side of
the nasal septumthe nasal septum
– Create turbulence in theCreate turbulence in the
inspired airinspired air
• To increase epithelialTo increase epithelial
surface areasurface area
• To warm and humidifyTo warm and humidify
inhaled airinhaled air

20. Nasal spine of the frontal bone n
nasal bones.
• Present in front sloping downwards.
• At the back is sloping anterior aspect of
sphenoid body.
• The surface marking of cribriform plate is
horizontal plane on which pupils lie as eyes gase
directly forwards.
• Skin of external nose is reflected around naris to
line vestibule.
• That Part of nasal caity bounded by the ala.

22. • Skin here bears stiff hairs.
• The mucocutaneous junction is marked by
a cresentic infolding,limen nasi.
• This coincide with upper margin of major
alar cartilage.
• Mucous membrane lining the roof n upper
part of septum n laterall wall is
OLFACTORY EPTITHELIUM.
• Mucous secretion traps particulate matter
n ciliary action wafts the mucous film back
into nasopharynx.

23. Watery secretion of serous glands
• Evaporates to moisten the inspired air.
• Mucous membrane is very vascular with large
venous sinusoids and arteriovenous shunts.
• Especially over inferior concha n this helps to
warm the inspired air.
• Mecous membrane of nose is adherent to
underlying periosteum or perichondrium of
nasasl walls.
• When a submucous resection is perforemed
surgically mucoperichondrium n
mucoperiosteum are elevated before resection
of septal cartilgae and bone.

25. Sphenoethmoidal recess
• Lies above n behind superior concha. It
receives ostium of sphenoidal air sinus.
• THE SUPERIOR CONCHA.
• Is small.it extends posteriorly from its
junction with middle concha.
• Its lower edge is free n overlies superior
meatus into which drain posterior
ethmoidal air cells.

30. Middle concha
• Is midway in size n position between superior n
inferior.
• Extends back from its junction with superior
concha.
• It overhangs the middle meatus.
• Which can be seen only when the concha is
displaced.
• Behind the posterior end of middle concha the
mucous membrane is the sphenopalatine
foramen.
• Flat area in front of the concha is atrium of nose.

31. Middle meatus
• Presents a convex bulge beneath concha.
• Ethmoidal bulla of ethmoid produced by buldging
of middle ethmoidal air cells.
• Open on or above bulla.
• A curved two dimensional slit the hiatus
semilunaris is present anteriorly to the bulla.
• Between the anterior surface of bulla and
posterior edge of uncinate process( a thin,hook
like bony leaflet which projects posteroinferiorly
from ethmoidal labyrinth).

34. Hiatus semilunaris
• Leads into ethmoidal infundibulum,
• A curved cleft bordered medially by uncinate
process n laterally by orbital plate of ethmoid.
• Infundibulum extends upwards n forwards n is
frequently continous with frontonasal recess .
• In this frontal sinus often opens.
• Anterior ethmoidal cells opens into infundibulum
or frontonasal recess.
• Attachment of middle concha,referred by
rhinologists as ground lamella of middle
turbinate.
• Considered as to divide ethmoidal air cells into
anterior n posterior ethmoidal systems.

35. Blood supply
• Sphenopalatine branch of maxillary artery.
• Supplies mucosa over the conchae n
meatuses n also much of septum.
• Anastomosis with septal branch of labial
( entering through the nostril) n ascending
branch of greater palatine ( entering
through incisive canal).
• Forming KISELBACH’S PLEXUS.On
lower anterior part of septum.Little’s area).
• A common site for epistaxis.

38. Anterior n posterior ethmoidal
branches.
• Of opthalmic artery enter nose from orbit
and supply roof n upper parts of lateral
wall n septum.
• Mean while both external n internal carotid
artery systems supply the nose.

43. Venous drainage
• Veins accompany arteries n drain in
various directions to the pterygoid
plexus,facial vein n ohthalmic veins.
• Rarely 1 percent an emissary vein may
traverse foamen caecum in front of
cribriform plate n connect nasal veins with
superior sagittal sinus.

45. Lymph drainage
• Lymphatics drain to
submandibular,retropharyngeal n deep
cervical nodes.
• Nerve supply.
• Olfactory ara of roof n upper parts of
lateral walls n septum are supplied by
olfactory nerves.
• Vestibular area is supplied by the
infraorbital lnerve from face.

48. The respiratory area of lateal wall
nerve supply.
• at front by anterior ethmidial nerve in upper part.
• In lwer part by filaments from anterior superior
alveolar nerve.
• At the upper back aprt by lateral posterior
spperior nasal branches from pterygopalatine
ganglion(through sphenopalatine foramen)
• At lower back part by posterior inferior nasal
branches of greater palatine nerve(through
foramina in perpendicular plate of ethmoid bone.