- •1. Topographic Surface Anatomy
- •Guide
- •Facts & Hints
- •Guide
- •Facts & Hints
- •3. Superficial Face
- •Guide
- •Facts & Hints
- •4. Neck
- •Guide
- •Facts & Hints
- •5. Nasal Region
- •Guide
- •Facts & Hints
- •6. Oral Region
- •Guide
- •Facts & Hints
- •7. Pharynx
- •Guide
- •Facts & Hints
- •Guide
- •Facts & Hints
- •Guide
- •Facts & Hints
- •Guide
- •Facts & Hints
- •Guide
- •Facts & Hints
- •Guide
- •Facts & Hints
- •13. Cerebral Vasculature
- •Guide
- •Facts & Hints
- •14. Topographic Anatomy
- •Guide
- •Facts & Hints
- •Guide
- •Facts & Hints
- •16. Spinal Cord
- •Guide
- •Facts & Hints
- •Guide
- •Facts & Hints
- •Thorax
- •18. Topographic Anatomy
- •Guides
- •Facts & Hints
- •19. Mammary Gland
- •Guides
- •Facts & Hints
- •20. Body Wall
- •Guides
- •Facts & Hints
- •21. Lungs
- •Guides
- •Facts & Hints
- •22. Heart
- •Guides
- •Facts & Hints
- •23. Mediastinum
- •Guides
- •Facts & Hints
- •Abdomen
- •24. Topographic Anatomy
- •Guide
- •Facts & Hints
- •25. Body Wall
- •Guide
- •Facts & Hints
- •26. Peritoneal Cavity
- •Guide
- •Facts & Hints
- •27. Viscera (Gut)
- •Guide
- •Facts & Hints
- •28. Viscera (Accessory Organs)
- •Guide
- •Facts & Hints
- •29. Visceral Vasculature
- •Guide
- •Facts & Hints
- •30. Innervation
- •Guide
- •Facts & Hints
- •Guide
- •Facts & Hints
- •32. Topographic Anatomy
- •Guide
- •Facts & Hints
- •Guide
- •Facts & Hints
- •Guide
- •Facts & Hints
- •35. Urinary Bladder
- •Guide
- •Facts & Hints
- •Guide
- •Facts & Hints
- •Guide
- •Facts & Hints
- •Guide
- •Facts & Hints
- •39. Testis, Epididymis & Ductus Deferens
- •Guide
- •Facts & Hints
- •40. Rectum
- •Guide
- •Facts & Hints
- •41. Vasculature
- •Guide
- •Facts & Hints
- •42. Innervation
- •Guide
- •Facts & Hints
- •Upper Limb
- •43. Topographic Anatomy
- •Guide
- •Facts & Hints
- •Guide
- •Facts & Hints
- •Guide
- •Facts & Hints
- •Guide
- •Facts & Hints
- •Guide
- •Facts & Hints
- •48. Neurovasculature
- •Guide
- •Facts & Hints
- •Lower Limb
- •49. Topographic Anatomy
- •Guide
- •Facts & Hints
- •Guide
- •Facts & Hints
- •51. Knee
- •Guide
- •Facts & Hints
- •Guide
- •Facts & Hints
- •Guide
- •Facts & Hints
- •54. Neurovasculature
- •Guide
- •Facts & Hints
5 Nasal Region
STUDYAIMS
At the end of your study, you should be able to:
Outline the structures that form the nasal region Describe the gross structure of the external nose Describe the nasal septum
Define the boundaries of the nasal cavity
Describe the structure of the nasal cavityincluding its blood supply, venous and lymphatic drainage, and innervation Describe the origin of the paranasal sinuses and their relationship to the nasal cavity
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GUIDE
Head and Neck: Nasal Region
Nasal region
External nose
Nasal cavities
Divided bynasal septum
Filter, humidifyand warm air
Contain specialised olfactorymucosa
Receive secretions from paranasal sinuses and nasolacrimal duct
Includes related paranasal sinuses
External Nose
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The nose is composed primarilyof cartilages except at the "bridge" of the nose where the nasal bone resides.Anteriorly, the air enters or leaves the nose via the nares, which open into the nasal vestibule, whereas posteriorlythe nasal cavitycommunicates with the nasopharynxvia paired apertures called the choanae.
Composed of bone and hyaline cartilage Bones
Paired nasal bones
Frontal processes of maxilla
Nasal part frontal bone
Cartilages
Paired lateral cartilages
Paired alar cartilages
Septal cartilage
Associated muscles dilate and flatten nares (nostrils)
Nasalis
Compressor nares
Dilator nares
Innervation ophthalmic and maxillarydivisions of trigeminal nerve (cranial nerve [CN] V1 and V2)
Blood supply
Ophthalmic artery
Facial artery
Venous drainage
Facial veins → internal jugular veins
Ophthalmic veins → cavernous sinus
Nasal septum
The nasal cavityis separated from the cranial cavitybyportions of the frontal, ethmoid, and sphenoid bones, and from the oral cavityinferiorlybythe hard palate.Anasal septum, usuallydeviated slightlyto one side or the other, divides the nasal cavityinto right and left chambers. The anterior third of the nasal septum is cartilaginous and the posterior two thirds is bony.
Divides nasal cavityinto two chambers
Composed of
Bone
Vomer
Perpendicular plate of ethmoid
Septal cartilage
Septal cartilage articulated with edges of bonyseptum
Nasal Cavity
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The lateral wall of the nasal cavityis characterized bythree shell-like conchae, or turbinates, that protrude into the cavity, and along with their covering of nasal respiratoryepithelium, theygreatlyincrease the surface area for warming, humidifying, and filtering the air.At the most superior aspect of the nasal cavityresides the olfactoryregion, with its olfactoryepithelium and specialized sensorycells for the detection of smells.
Each cavitynarrow above and wider below, separated from each other bynasal septum
Extend from nares to choanae
Naris = external opening of nose
Choana = opening into pharynx
Vestibule
First part of cavity
Lined with skin with hairs
Bounded laterallybyalar cartilages
Limen nasi
Crescentic line
Marks upper limit of vestibule
Nasal mucosa
Lines nasal cavities except for vestibule
Bound to periosteum and perichondrium of surrounding bones and cartilages
Extends into all chambers, cavities and sinuses communicating with nasal cavities
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Upper one third is olfactoryareas (mucosa)
Lower two thirds is respiratoryareas (mucosa) Boundaries (walls) of nasal cavity
Nasal conchae
Three horizontal projections from lateral wall
Superior, middle and inferior nasal conchae
Divide nasal cavityinto four areas
Superior meatus
Middle meatus
Inferior meatus
Sphenoethmoid recess Superior meatus
Between superior and middle conchae
Has openings from posterior ethmoidal sinuses Middle meatus
Wider and longer than superior
Depressed area-atrium-at anterior end
Ethmoid infundibulum at anterior end
Leads to frontonasal duct
Duct leads to frontal sinus
Ethmoidal bulla (swelling)
Rounded projection at inferior root of middle meatus
Represents bulge of ethmoid air cells (sinuses)
Groove called semilunar hiatus immediatelybeneath leads to infundibulum
Contains openings for frontal, maxillary, and anterior ethmoidal sinuses
Frontal sinus opening at anterior end of semilunar hiatus/infundibulum
Maxillarysinus opening at posterior end of semilunar hiatus
Variable openings for ethmoid air cells Inferior meatus
Below inferior concha
Receives nasolacrimal duct opens into anterior end Sphenoethmoidal recess:
Posterior and superior to superior concha
Receives opening of sphenoidal sinus Innervation
Posterior region of nasal cavity
Nasal septum: maxillarynerve (CN V2) → nasopalatine nerve to nasal septum
Lateral wall: lateral branches of lateral palatine nerve
Anterior and superior regions of nasal cavity: anterior and posterior ethmoidal nerves, branches of nasociliarynerve from ophthalmic nerve (CN V1)
Olfactoryepithelium innervated byolfactorynerve (CN I) Arterial supply
Sphenopalatine artery(branch of maxillaryartery)
Anterior and posterior ethmoidal arteries
Greater palatine artery
Superior labial and lateral nasal branches of facial artery Venous drainage
Plexus of veins beneath nasal mucosa drains to
Sphenopalatine veins
Facial veins
Ophthalmic veins Lymphatic drainage
Posterior nasal cavityto retropharyngeal nodes Anterior nasal cavityto submandibular nodes
Paranasal sinuses
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Sinus |
Description |
Frontal |
Paired sinuses, lying anteriorlyin frontal bone and draining into semilunar hiatus of middle meatus |
Ethmoid |
Paired anterior, middle, and posterior sinuses in ethmoid bone; anterior and middle draining into middle meatus |
|
(hiatus semilunaris and ethmoid bulla, respectively), and posterior, into superior nasal meatus |
Sphenoidal |
Paired sinuses, in sphenoid bone, draining into sphenoethmoidal recess |
Maxillary |
Paired sinuses, in maxilla, draining into middle meatus (semilunar hiatus); largest sinus (20-30 ml) |
There are four pairs of paranasal sinuses, which are open chambers within several of the bones surrounding the nose and orbits. Theyare lined with respiratoryepithelium, assist in warming and humidifying the inspired air, and drain their mucus secretions into the nasal cavities. Blowing the nose clears the nasal cavityand sinuses of excess secretions.
Extensions of nasal cavityinto maxillary, ethmoid, frontal, and sphenoid bones
Lined with respiratoryepithelium
Present at birth and increase in size until adulthood
Air filled
Frontal sinuses (2)
Between inner and outer tables of frontal bone
Can be detected around age 7
Maxillarysinuses (2)
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Largest of paranasal sinuses
Occupymost of bodyof maxillae Ethmoidal sinuses
Several in number
Not well developed until after age 2 Sphenoidal sinuses
Derive from extensions of ethmoidal sinuses into sphenoid bone around 2 years of age
Numbers different on either side
Bonyseptum between two sides
Onlya thin plate of bone separates them from critical structures in the anterior and middle cranial fossae: optic nerves, pituitary gland, internal carotid arteries, cavernous sinuses
[Plate 46, Orientation of Nerves and Vessels of the Cranial Base]
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