This is just a revision of anatomy that we read in basic science and this will help in approaching clinical ent.

1. Anatomy Of Nose
6th semester mbbs
nischal shrestha

2. External Nose
• Pyramidal in shape with its root up and base downwards
• Osteocartilaginous covered by muscles and skin

4. Bony Part
• Upper 1/3rd of external nose
• Consists of 2 nasal bones and rest on upper part of nasal process of frontal bone
and held between frontal processes of maxillae

6. Cartilaginous Part
1. Upper lateral cartilages : the lower free edge is seen intranasally as
limen vestibule, nasal valve or limen nasi on each side.
2. Lower lateral cartilages (alar cartilage) : each is U shaped. It has lateral
and medial crus.
3. Sesamoid cartilage (lesser ala) : 2 or more in number
4. Septal cartilage : it supports dorsum of cartilaginous part of nose. In septal
abscess or after excess removal of septal cartilage as in submucosal
resection (SMR) operation, support of nasal dorsum is lost and a supratip
depression results.

9. Nasal Musculature
1. Processus
2. Nasalis (transverse and ala parts)
3. Levator labii superioris alaeque nasi
4. Anterior and posterior dilator nares
5. Depressor septi

11. Nasal Skin
• Skin over nasal bones and upper lateral cartilages is thin and freely mobile
• That covering the alar cartilages is thick and adherent, and contains many
sebaceous glands
• It is the hypertrophy of these sebaceous glands that gives rise to a lobulated
mass called rhinophyma.

13. Internal Nose
• Divided into right and left nasal cavities by nasal septum
• Each cavity communicates with exterior through naris or nostril and with
nasopharynx through posterior nasal aperture or choana.
• Each nasal cavity consists of a skin lined portion –the
vestibule and a mucosa lined portion – the nasal cavity
proper

15. Vestibule Of Nose
• Lined by skin and contains sebaceous glands , hair follicles and hair called
vibrissae.
• Its upper limit on the lateral wall is marked by limen nasi aka nasal valve
1. Nasal Valve : bounded laterally by lower border of upper lateral cartilage
and fibrofatty tissue and anterior end of inferior turbinate , medially by
cartilaginous nasal septum and caudally by floor of pyriform aperture.
The angle between nasal septum and lower border of upper lateral
cartilage is nearly 30 deg
2. Nasal valve area : it is least cross sectional area of nose and regulates
airflow and resistance on inspiration.

17. Nasal Cavity Proper
• Each cavity has a lateral wall , a medial wall , a roof and a floor.

18. Lateral Nasal Wall
• 3 & occasionally 4 turbinates or conchae
• They are bony projections covered by mucous membrane. The spaces
between them are meatuses.
• Inferior Turbinate : it is a separate bone and below it , into
inferior meatus , opens nasolacrimal duct guarded at its terminal end by a
mucosal valve called Hasner’s valve.

19. Middle Turbinate
• A part of ethmoid bone
• Attached to lateral wall by a bony lamella called ground or basal lamella.
• Its attachment is not straight but in an S shaped manner.
• In the anterior third , it lies in sagittal plane and attached to lateral edge of
cribriform plate , in the middle third lies in frontal plane and attached to
lamina papyraceae while in its posterior third , it runs horizontally and
forms roof of middle meatus and is attached to lamina papyraceae and
medial wall of maxillary sinus.
• The ostia of various sinuses draining anterior to basal lamina form anterior
group of paranasal sinuses while those open posterior & superior to it forms
posterior group.

21. Middle Meatus
• Uncinate process is a hook like structure
• Its posterosuperior border is sharp and runs parallel to anterior border of
bulla ethmoidalis ; the gap between two is hiatus semilunaris (inferior).
• The anteroinferior border is attached to lateral wall. Posteroinferior end is
attached to inferior turbinate dividing the membranous part of lower middle
meatus into anterior and posterior fontanelle. The fontanel area is devoid of
bone and consists of membrane only and leads into maxillary sinus when
perforated.
• Upper attachment shows great variation and may b inserted into lateral
nasal wall, upwards into baso of skull or medially into middle turbinate.
• Space limited medially by uncinated process & frontal process of maxilla and
laterally by lamina papyraceae is called infundibulum
• Natural ostium of maxillary sinus situated in lower part of infundibulum .
Accessory ostium in anterior or posterior fontanel

25. Bulla Ethmoidalis
• Ethmoidal cell situated behind uncinated process.
• Anterior surface forms posterior boundary of hiatus semilunaris
• When there space above or behind the bulla, it is called suprabullar or
retrobullar recesses, respectively.
• Both recesses together form lateral sinus ( sinus lateralis of Grunwald)
• The cleft like communication between the bulla and skull base and opening
into middle meatus is also called hiatus semilunaris superior.

27. Atrium Of The Middle Meatus
• Shallow depression lying in front of middle turbinate and above nasal
vestibule.

28. AGGER NASI
• It is elevation just anterior to attachment of middle turbinate.

29. Superior Turbinate
• Also ethmoturbinal & is situated posterior and superior to middle meatus.
• It forms important landmark to identify ostium of sphenoidal sinus which
lies medial to it.

30. Superior Meatus
• Posterior ethmoid cells open into it
• no of ethmoid cells varies from 1 to 5
• Onodi cell is a posterior ethmoid cell which grow posteriorly by the side of
sphenoid sinus or superior to it for as much distance as 1.5 cm from anterior
surface of sphenoid.
• Onodi cells are surgically important as optic nerve may b related to its
lateral wall.

31. Sphenoethmoidal Recess
• Situated above superior turbinate
• Sphenoidal sinus opens into it

32. Supreme Turbinate
• Sometimes present above superior turbinate and has narrow meatus
beneath it

33. Medial Wall
• Nasal septum forms medial wall
• It consists of three parts
1. Columellar Septum : formed of columella containing of medial crura of alar
cartilage
2. Membranous Septum : consists of double layer of skin with no bony or
cartilaginous support . It lies between columella and caudal border of
septal cartilage. Both columellar & membranous parts are freely movable
from side to side.
3. Septum proper : consists of osteocartilaginous framework covered with
nasal mucous membrane.

35. Septum Proper
1. Perpendicular plate of ethmoid
2. Vomer
3. Large septal (quadrilateral) cartilage. Other bones which make minor
contributions at periphery are
a) Crest of nasal bones
b) Nasal spine of frontal bone
c) Rostrum of sphenoid
d) Crest of palatine bones & maxilla
e) Anterior nasal spine of maxilla

36. Roof
• Anterior sloping part of roof is formed by nasal bones, posterior sloping by
body of sphenoid bone and middle horizontal part is formed by cribriform
plate of ethmoid through which olfactory nerves enter nasal cavity.
•Floor: formed by palatine process of maxilla in its anterior 3/4th and
horizontal part of palatine bone in its posterior 1/4th.

39. Lining Membrane Of Internal Nose
1. Vestibule : lined by skin containing hair, hair follicles and sebaceous glands
2. Olfactory Region : upper 1/3rd of lateral wall (upto superior concha) ,
corresponding part of nasal septum and roof of nasal cavity from olfactory
region. Here , mucous membrane is pale in color.
3. Respiratory Region : lower 2/3rd of nasal cavity forms it.

41. Nerve Supply