1. Anatomy of Nose & Paranasal Sinuses
Dr. Vishal Sharma

2. Development of nose

3. Face develops from 5 projections: frontonasal process (ectoderm over forebrain) + 2 maxillary processes + 2 mandibular processes (1st arch)
An ectodermal olfactory placode divides fronto-nasal 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 tecto-septal expansion from Rathke’s pouch

16. External Framework

17. External Framework Nasal Bone Frontal Process of Maxilla
Upper Lateral Nasal Cartilage
Lower Lateral Nasal (Alar) Cartilage
Septal Cartilage
Lesser Alar (Sesamoid) Cartilages

18. Internal Nose Openings: Anterior nares & posterior nares (Choanae).
Vestibule of nose: lined by skin
Nasal cavity proper:
 Lateral Wall  Medial Wall (Septum)
 Roof  Floor

20. Nasal Septum

21. Nasal Septum

22. Nasal Septum 1. Septal cartilage 7. Medial alar crus
2. Ethmoid plate Upper lateral cartilage
3. Vomer Nasal bone crest
4. Palatine crest Frontal spine
5. Maxillary crest Sphenoid rostrum
6. Vomeronasal Membranous septum
cartilage

27. 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.

28. 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

31. Ostio-meatal Complex

32. 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).

33. Variants in O.M.C. Concha bullosa (pneumatized M.T.)
Paradoxically curved middle turbinate
Medially turned uncinate process
Large bulla ethmoidalis
Haller’s cell in orbital floor
Agger nasi cell anterior to M.T.
Onodi Cell with dehiscent Optic Nerve
Mucosal pathology

34. Concha bullosa

35. Concha bullosa

36. Paradoxically curved M.T.

37. Paradoxically curved M.T.

38. Medialized Uncinate Process

39. Large bulla ethmoidalis

40. Haller cell

41. Agger nasi cell

42. Onodi cell with dehiscent optic nv

43. Mucosal disease

44. Blood Supply Sphenopalatine artery (main artery)
Greater palatine artery
Superior labial artery
Anterior Ethmoidal artery
Posterior Ethmoidal artery
1, 2, 3 & 4 form Kiesselbach’s plexus over Little’s area on anterior septum

48. 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

49. Sensory Nerve Supply Long & short Nasopalatine nerves
Greater palatine nerve
Infra-orbital nerve branches
Anterior ethmoidal nerve
Olfactory nerve

52. 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

53. 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

54. Lining Epithelium

55. 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

56. Paranasal Sinuses Anterior group:  frontal  anterior ethmoidal
 maxillary
Posterior group:
 posterior ethmoidal
 sphenoid

60. First X-ray appearance
Development of P.N.S.
Appear first
First X-ray appearance
Reach adult size by
Maxillary
At birth
4 mth
15 yr
Ethmoidal
1yr
12 yr
Sphenoid
2 yr
4 yr
18 yr
Frontal
6 yr

62. Sphenoid Sinus Relations

67. 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

68. Muco-ciliary blanket

69. Muco-ciliary blanket

70. Thank You