7) The Nose Flashcards
What is the external nose comprised of?
Bony component
Predominantly cartilaginous
Nostrils bounded laterally by alae
Skin, extends into vestibule
Which bones make up the bony part of the nose?
Nasal bones
Maxillae frontal processes
Frontal bone (nasal part & nasal spine)
How many cartilages make up the cartilaginous portion of the nose?
2 Lateral cartilages
2 Alar cartilages
1 Septal cartilage
How is the nasal septum comprised?
Anterior portion - Cartilaginous
Middle portion - Perpendicular plate of Ethmoid bone
Posterior portion - Vomer
Why are nasal fractures the most common facial fractures?
Exposed organ
History of force to face, deformity
Complications - septal haematoma
What components make up the nasal cavity?
Nostrils
Chonchae (turbinates)
Mucosal lining (except for vestibule)
How many conchae are there in the nasal cavity?
Superior nasal conchae
Middle nasal conchae
Inferior nasal conchae
forming 5 passages (recesses/meatus)
What are the 5 passages in the nasal cavity?
Spheno-ethmoidal recess Superior meatus Middle meatus Inferior meatus Hard palate
How is the spheno-ethmoidal recess modified for olfaction?
Lining epithelium of mucous membrane
Axonal processes of olfactory cell pass through cribriform plate, penetrate meninges & enter olfactory bulb
Name the openings in the nasal cavity
Cribriform plate (CNI)
Sphenopalatine foramen
Incisive foramen
Foramen cecum (nasal veins)
What is the arterial supply to the nasal cavity?
Branches of:
Ophthalmic artery (ICA)
Maxillary & Facial arteries (ECA)
What is Kiesselbach’s/Little’s area of the nasal cavity?
Rich anastomoses on anterior part of septum of nasal cavity (between vestibular & mucosal lining)
Lots of capillaries - extensive blood supply
Which area of the nose causes profuse bleeding during nose bleeds?
Kiesselbach’s/Little’s area
What is epistaxis?
Bleeding from the nose (nose bleed)
Very common
Anterior bleeds 90%
Posterior bleeds - sphenopalatine artery
Describe the venous drainage of the nose
Submucosal venous plexus drains into:
- Cavernous sinus
- Facial vein
- Pterygoid plexus
Which nerves innervate the nasal cavity?
Olfactory (CNI) - smell
Maxillary (CNVii) & Nasopalatine nerve - posteroinferior nasal mucosa
Ophthalmic (CNVi) & Ant. + Post. Ethmoidal nerves - anterosuperior nasal mucosa
External nasal (CN Vi) & Infraorbital (CN Vii) - External nose
What types of epithelium can be found in the nasal cavity?
Respiratory: pseudostratified columnar cililated + goblet cells
Olfactory: Olfactory cells & receptors
What are the 4 paranasal sinuses?
Frontal
Ethmoidal
Sphenoid
Maxillary
Where do the frontal sinuses drain?
Frontonasal duct into ethmoidal infundibulum
to Middle nasal recess
Where do the ethmoidal sinuses drain?
Middle nasal recess (anterior & middle ethmoidal cells)
Superior nasal recess (posterior ethmoidal cells)
Where do the sphenoidal sinuses drain?
Sphenoethmoidal recess
Where do the maxillary sinuses drain?
Maxillary ostium to middle nasal recess via semilunar hiatus
Where may infections of the nasal cavity spread?
Anterior cranial fossa via cribriform plate
Paranasal sinuses via openings in nasal cavity
Lacrimal apparatus & conjunctiva via opening of nasolacrimal duct
Middle ear via eustachian tube
What is rhinitis?
Inflammation of the nasal mucosa swelling & increased volume of secretion Causes: - infective (viral) adeno/rhinovirus, RSV - allergic - nasal polyps
