The document provides details on the anatomy of the internal nose. It describes how the nasal cavity is divided into right and left cavities by the nasal septum. Each cavity has a skin-lined vestibule and mucosa-lined nasal cavity proper. The vestibule contains hair follicles and sebaceous glands. The document further describes the structures that make up the lateral wall of the nose such as the turbinates, meatuses, osteomeatal complex and its related structures. It also discusses the blood supply, nerve supply, lymphatic and venous drainage of the internal nose.

1. Anatomy of Internal
Nose
DR. ARJUN ANTONY GRAISON
MSENT, DNB, DOHNS
MGM MEDICAL COLLEGE,
AURANGABAD

2. ANATOMY OF NOSE
INTERNAL NOSE
 It is divided into right and left nasal cavities by nasal septum.
 Each nasal cavity consists of
a) Skin lined portion-vestibule (contains sebaceous glands, hair follicles,
vibrissae)
b) Mucosa lined portion-nasal cavity proper

3. Vestibule
of Nose
 Anterior & inferior portion of Nasal cavity
 Lined by skin, sebaceous glands,hair follicles & hair ( Vibrrissae)
 Upper limit on lateral wall marked by – Limen nasi / nasal valve
 Internal nasal valve-triangular area bounded
1. Laterally- by caudal edge of Upper Lateral Cartilage & Inf turbinate
head(Ant end) ,
2. Medially- cartilaginous nasal septum
3. Inferiorly- pyriform aperture
4. Nasal valve area – 0.73cm2

4. Nasal Septum Cavernous body
 Synonyms: Septal turbinate, septal cavernous body, Kiesselbach's
body, septal erectile tissue.
 Introduction: This is a widened area of nasal septum located superior to the inferior
turbinate and anterior to the middle turbinate.
 It is composed of septal cartilage. Septal cartilage is thicker here than the other
parts of nasal septum. The mucosal covering of septal body is thicker than the other
portions of nasal septum.
 This body is in intimate relationship to the internal nasal valve. It is suspected to play
a role in the maintenance of nasal resistance.
 Histologic criteria for the identification of septal body:
1. The lining epithelium is pseudostratified columnar epithelium with goblet cells.
2. The epithelium is 60 – 100 μm thick.
3. Many seromucinous glands are present
4. Numerous blood sinusoids are present
 Should be differentiated from High septal deviation.

5. Nasal Cavity Proper:-
 Nasal cavity proper: bounded by lateral wall, medial wall, roof and a
floor.
 Floor: Formed by
a) Palatine process of maxilla (anterior 3/4th )
b) Horizontal process of palatine bone (posterior 1/4th )
 Roof: formed by
a) Anterior sloping part by nasal bones
b) Posterior sloping part by body of sphenoid
c) Middle horizontal part by cribriform plate of ethmoid through which
olfactory nerves enter the nasal cavity

6. Nasal Septum:-
3 parts
• Columellar Septum- formed by columella with
medial crura of alar cartilage,unted by fibrous
tissue,covered in skin either side.
• Membranous Septum-double layer of skin with no
bone or cartilage support
• Septum proper:-
1. Quadrilateral septal cartilage
2. Perpendicular plate of ethmoid
3. Vomer
4. Crest of nasal bone
5. Crest of Maxilla
6. Crest of Palatine bone
7. Ant Nasal spine of frontal bone
8. Ant nasal spine of maxilla
(2 spines & 3 crests)
Cottle’s Line

7. Lateral Wall of Nose:-
 Formed by sup, middle &inf turbinates and their meatuses
 Middle and inferior turbinate are imp surgically
 Middle turb is extension of ethemoid bone
 Inf turb ,separate bone
7

8. Nasal Septum Blood
Supply
Little’s area/ Kiesselbach’s plexus: LEGS (pneumonic)
L- Superior LABIAL artery of Facial artery
E- Anterior Ethmoidal artery
G- Greater palatine artery (thru incisive foramen)
S- Sphenopalatine artery
Retrocollumellar Vein: runs vertically downwards behind
columella,crosses floor of nose and joins venous plexus on
lateral wall of nose.
Woodruff’s Plexus:-
Anastomosis b/w Posterior Ethmoidal artery
(pharyngeal & postnasal branches)
& posterior ethmoid artery

9. Lateral Wall Bloody
Supply

10. Pterygopalatine fossa infiltration:

11.  A to B- Soft tissue mean thickness –
6.9mm
 B to C-Greater palatine Canal mean
length- 18.5mm
 C to D- Mean height of
pterygopalatine fossa – 21.6mm
 Therefore for effective infiltration of
pterygopalatine fossa, needle should
be bent at 25mm from tip at an angle
of 45 degrees.
 Thus needle tip just penetrates
pterygopalatine fossa without putting
any of the contents at risk.
 Transoral pterygopalatine block 1st
step of Sphenopalatine artery ligation.
 Block application also in treatment of
Cluster Headache.

12. Lining Membrane of Nasal Cavity
 Vestibule- lined by skin,hair follicles and sebaceous glands
 Olfactory region- Upper 1/3 of lateral wall (upto the superior
concha),corresponding part of nasal septum and nasal cavity roof form
part of olfactory region. Mucous membrane here is paler in colour.
 Respiratory region- Formed by lower 2/3rd of nasal cavity.Surface line by
Pseudostratified ciliated columnar epithelium with plenty of goblet
cells.
 In the submucosal layer of the mucous membrane are situated serous,
mucous and both serous & mucous secreting glands,the ducts of which
open on the surface of the mucosa.

13. 13
Nerve supply- internal
3 types;
1-Olfactory Nerves
2-Nerves of commonsensation
• Ant Ethmoidal nerve
• Br of Sphenopalatine ganglion
• Br of infraorbital nerve
3- Autonomic nerves
Infraorbital nerve supplies
the vestibule medially &
Laterally.

15. Nasal
Pathways
Of
Referred
Otalgia

16. Parasympatetic Greater Superficial
petrosal Nerve
Vidian Nerve
RELAYS in
Sphenopalatine
ganglion
Supply Nasal glands &
control secretion &
Vasodilatation of Blood
vessels
Sympathetic
(C1 & C2)
Deep Petrosal Nerve Vidian Nerve
DOES NOT RELAY in
Sphenopalatine
ganglion
Cause
VASOCONSTRICTION

17. Sphenopalatine/
Meckel/
Pterygopalatine
ganglion
Pteygopalatine fossa
conents:-
Maxillary nerve &
Artery &
Pterygopalatine
ganglion.

18. 18
Venous
drainage
•External veins of nose
drain to angular and
opthalmic veins

19. LYMPHATIC DRAINAGE
 The anterior nasal cavity drains with the external nose to the
submandibular nodes while
 Posterior nasal cavity drains to the Upper jugular lymph nodes
either directly or through the retropharyngeal nodes.

20. Lateral Nasal Wall
 Formed by 8 bones
 4 large bones – Maxilla , Frontal , the Ethmoid & the sphenoid,last 3 are
single unpaired.
 4 small bones – the inferior turbinate, the lacrimal, the palatine & the nasal
bones

21. The Maxillary Hiatus:
It is a large opening in the in the maxillary bone
,which is closed off by processes of different
bones.
They are
1. Ant- descending process of lacrimal bone
2. Ant Inf- uncinated process of ethmoid bone
3. Inf- maxillary process of inf turbinate
4. Post- perpendicular plate of the palatine bone.

22. INFERIOR TURBINATE
Inferior Turbinate is a Separate Bone.
It is a MAXILLO TURBINATE
Whereas
Middle, Superior & Supreme turbinates are
ETHMOIDAL TURBINATES.

23. INFERIOR MEATUS

25. OSTEOMEATAL COMPLEX
 The middle meatus is the space below and lateral to the middle turbinate, and
is often functionally referred to as the osteomeatal complex. It contains the
drainage pathways for the anterior ethmoids, the maxillary and the frontal
sinuses.
 The middle meatus is the area that is most commonly involved in the
pathophysiology of chronic rhinosinusitis.
 This term is used by the surgeon to indicate the area bounded by the
middle turbiante medially, the lamina papyracea laterally, and the basal
lamella superiorly and posteriorly. The inferior and anterior borders of the
osteomeatal complex are open.
 The contents of this space are the aggernasi, nasofrontal recess (frontal
recess), infundibulum, bulla ethmoidalis and the anterior group of
ethmoidal air cells.

26. OSTEOMEATAL COMPLEX-
RELATED STRUCTURES
The ethmoidal infundibulum:
 It is a cleft-like, three dimensional space in the lateral wall of the
nose that belongs to the anterior ethmoid.
 Boundaries:
 Medially: Uncinate process
 Laterally: Lamina papyracea of the orbit
 Anteriorly: Uncinate process
 Posteriorly: Anterior surface of ethmoidal bulla
 New addition – inf also – uncinate

27. OSTEOMEATAL COMPLEX-
RELATED STRUCTURES
The 'hiatus semilunaris’:
(inferior hiatus semilunaris according to Grunwald)
 lying between the free posterior margin of the uncinate process
and the anterior surface of the ethmoidal bulla.
 Sickle-shaped two-dimensional space.
 The superior hiatus semilunaris :This cleft between the ethmoidal
bulla and the middle nasal meatus exists, when there is a marked
recess posterior to the ethmoidal bulla

28. OSTEOMEATAL COMPLEX-
RELATED STRUCTURES
 Uncinate process-
 It is superior extension of the ethmoid.
 Anteriorly it fuses with the postero medial wall of agger nasi cell
and postero medial wall of nasolacrimal duct.
 It has free superio-posterior edge.
 floor and medial wall of infundibulum is formed by the uncinate
process.
 It is approximately 3 to 4 mm wide and 1.5 to 2 cm in length.

29. Middle Turbinate
 Three components
 First – Anterior, oriented in a sagittal plane and attached
to skull base/ cribiform plate
 Second – Middle, oriented in a frontal plane and
attached to lamina papyracea (AKA basal lamella and
separatesant from post ethmoids)
 Third – Posterior, oriented in a horizontal plane and
attaches to perpendicular plateof palate (forms roof of
middle meatus, anterior to sphenopalatine foramen)

30. Middle Turbinate

31. Middle turbinate Attachments:-
Ant attachment to
Cribiform plate
Middle attachment to
lamina papyracea
Post attachment to
Perpendicular plate of
Palatine bone

32. Middle turbinate Anatomical variations
 Ballooned up – concha bullosa ( pneumatized from frontal recess,
agger nasi cell, anterior ethmoidal cells or middle meatus).
 Superior meatus pneumatize vertical lamella – interlamellar cell of
Gurnwald.
 Paradoxically bent turbinate.
 Tubinate sinus.

33. ANATOMICAL VARIATIONS

37. Lateral Sinus/Sinus lateralis of Grunwald

43. Uncinate stripped downwards to reveal the Maxillary
Sinus natural ostia.

44. Anterior & Posterior Nasal fontanelles
Nasal fontanelles are the areas of the lateral nasal wall that are absent of bone. They are
usually found immediately above the insertion of the inferior turbinate. Thus, the mucosa of
the maxillary sinus and the middle meatus are separated only by a fibrous layer of
periosteum.
Anterior Fontanelle
 Loc - inferior and anterior to the
uncinate process and fuses with the
medial wall of the maxillary sinus.
 has an important relationship to the
nasolacrimal apparatus.
 During retrograde uncinectomy, care
must be taken to avoid damage to
nasolacrimal duct.
 the mean distance from the maxillary
ostium to the nasolacrimal duct has
been reported to be approximately 0.9
cm
Posterior Fontanelle
 Boundaries - posterior end of the
uncinate process anteriorly and the
palatine bone posteriorly.
 relatively safe surgical landmark during
a middle meatal antrostomy.
 Implicated in chronic rhinosinusitis and
post nasal drip, cos of mucous
recirculation b/w natural & accessory
ostia - Two Hole Syndrome
 The antrostomy window should be
widened in a posterior direction by
excising the posterior fontanelle.

47. Frontal Sinus

50. Landmarks for Canine fossa
puncture/trepine

53. Uncinate Attachments
 Posteroinferiorly to the inferior
turbinate and palatine bone interiorly
 Anteroinferiorly attached laterally to
the lateral wall
Anatomic variation of uncinate
process (Superior Attachment)
 Extend upto skull base
 Attach to lamina papyracea.
 Attached to insertion of middle
turbinate.
 Lie free in middle meatus.
 May be pneumatized.

54. ANATOMIC VARIATION OF UNCINATE

57. Atelectatic Uncinate
• Collapse of uncinate on lamina
papyracea.
• High risk of orbital damage
• Occurs when there is complete
opacification of the maxillary sinus with
absorption of all the gas within the sinus.
• The resultant negative pressure sucks the
uncinated onto the lateral wall.
• Long standing complication is orbital
expansion may occur with enopthalmos
• The so called Silent Sinus Syndrome
• Def- spontaneous, asymptomatic
collapse of the maxillary sinus and
orbital floor associated with
negative sinuspressures. It can cause
painless facial asymmetry, diplopia and
enophthalmos.

58. Cribriform plate
Keros classification

59. Keros Classification
 Type I
 1-3mm
 Type II
 4-7mm
 Type III
 8-16mm

60. FRONTAL RECESS ANATOMY
 Frontal sinus drains in to middle meatus and nasal cavity by a complex
passage called frontal recess.
 Previously known as nasofrontal duct ( tubular structure conducting fluids
between frontal sinus and nasal cavity).
 After understanding of more accurate anatomy the term frontal recess was
recommended.
 KILLIAN is credited for coining the term frontal recess.
 Now a days the better term is frontal sinus drainage pathway.
.

61. FRONTAL RECESS ANATOMY
 Stammberger - frontal recess is superior
continuation of ascending groove
between first and second ET’s and frontal
sinus originates from anterior
pneumatization of frontal recess in
frontal bone.
 Boundaries –
laterally - Lamina papyracea, uncinate
process
medially – Middle turbinate
anteriorly- anterior wall of Agger nasi cell (
when present )
posteriorly- Anterior wall of Ethmoidal bulla
( if ethmoidal bulla is not reached up to skull
base,frontal recess will also connect to
suprabullar recess )

62. CT saggital view showing Frontal recess

63. FRONTAL RECESS ANATOMY
 In a saggital section frontal recess
along with frontal infundibulum and
frontal ostium forms hourglass
shaped structure.
 Thus frontal sinus is much anterior to
frontal recess when viewed
endoscopically.

66. Frontal recess leading to the frontal sinus

67. Agger nasi cell
Forms a bulge anterior
to the middle turbinate
on the lateral
wall…under a plain
structureless area lined
by nasal mucosa called
as atrium.

68. AGGER NASI CELL
 Agger nasi cell plays a significant role in frontal recess
obstruction, it may fill the recess but obstruction develops after a
modest degree of oedema .
 In previous surgery if agger nasi cap left in place, it may form
scar in contact to bulla leads to iatrogenic frontal sinus disease.
 During endoscopic dissection medial and posterior wall should
be located and removed to prevent leaving cap behind.

72. Ethmoid anatomy
 Ethmoid anatomy is complex: Labyrinth
 Lamellae principle by H. Stammberger
 1st - Uncinate
 2nd - Ethmoid bulla
 3rd - Basal lamella of middle
turbinate
 4th - Superior turbinate

83. Frontal Recess
 Anatomic Boundries:
 Ant – unicate process & agger nasi
 Post – bulla ethmoidalisand suprabullarlamella
 Lateral – lamina papyracea
 Medially – hiatus semilunarisor middle turb
 Inf – Ethmoid infundibulum
 Sup – Foveaethmoidalis,supraorbitalaircell, anteriorethmoid
arteryand frontal ostium

86. Frontal Cells

91. Sphenoid Ostium
 Medial toposteriorsup. Turbinate
 Located between nasal septumand inferioraspectof sup. Turbinate
 Located at the same level as the roof of the maxillary Sinus
 Located 4 microdebrider/suction tip breathsabovethe choanae
 Ostium lies high on its anterior wall close to its roof.
 Drain into sphenoethmoidal recess.
 Lies 1- 1.5 cm above the roof of posterior choana.

92. Sphenoid Ostium

93. Sphenoid Sinus
 Relationshipsof importantstructures:
 Optic nerve – superior-lateral
 Carotid artery/cav sinus – mid-lateral
 Vidian nerve and maxillary nerve – inferior-lateral

94. Square – ant clinoid process, Circles – optic canals, triangle – vidian nerve
Asterisk – pneumatization of pterygoid process

95. Sphenoid Classification

97. Onodi Cells or Sphenoethmoid cells
 10 % posterior ethmoidal cell extend posterolaterally over sphenoid sinus
– Onodi cell.

103. END Of PART 1