Anatomy/Physiology of Nose Flashcards
Epithelium of lining of the nose
columnar ciliated epithelium
Components of the external nose
Glabella Nasion Dorsum Supratip Tip Columnella
The nasal bones are composed of
the frontal processes of the maxillae and nasal part of the frontal bones
Deformities of the nose can be
congenital or acquired
Cause of acquired nose deformity
Trauma
What are the five cartilages of the nose?
One septal
Two lateral
Two alar
Components of internal nose
Midline partition
Lateral walls
Roof
Floor
What structures form the midline partition of the internal nose?
Nasal septum - septal cartilage and perpendicular plate of ethmoid and vomer
What structures form the lateral walls of the internal nose?
Turbinates - superior, middle and inferior
Meati
What forms the roof of the internal nose?
Cribriform plate
What forms the floor of the internal nose?
Hard palate
How is the septum clinically relevant?
Can be deviated, perforated or septal haematoma
What turbinate is most clinically relevant and why?
Inferior turbinate - can cause nasal blockage due to infection or inflammation
How is infection/inflammation of the inferior turbinate usually managed?
Medically with topical steroid sprays, surgery is unusual
Blood supply to the nose is broadly divided into
anterior and posterior supply
Anterior blood supply to the nose is derived from
branches of the internal carotid artery - anterior/posterior ethmoid arteries from ophthalmic artery
Posterior blood supply to the nose is derived from
branches of the external carotid artery - sphenopalatine artery from the maxillary branch
What is the blood supply of the mucosal lining of the septum? Why is this clinically relevant?
Capillary plexus - Little’s area
Most common site of epistaxis
The nose receives innervation from fibres from the
neuro-olfactory epithelium via the olfactory nerve
and from the infraorbital nerve
How might damage to the olfactory nerve occur?
Trauma
Virus
Tumours
Damage to the olfactory nerve might result in
hyposmia or anosmia
Damage to infraorbital nerve can result in
paraesthesia
What is the primary function of the nose?
To act as an airway in respiration
Other functions of the nose
Filtration
Humidification/warming of inhaled air
Mucus production, trapping, ciliary clearance
Immune protection
Olfaction
Drainage/aeriation of middle ear
Drainage of paranasal sinuses and nasolacrimal duct
What are the four groups of paranasal sinuses?
Frontal
Ethmoid
Sphenoid
Maxillary
Frontal, maxillary and anterior ethmoid sinuses are known as the
anterior sinuses
Where do the anterior paranasal sinuses drain?
To middle meatus via natural mucociliary pathways
Sphenoid and posterior ethmoid sinuses are known as
posterior sinuses
Posterior sinuses draw into the
inferior meatus
What is the lining of the paranasal sinuses?
Mucociliary - continuous with the nose
Important anatomical relations of the paranasal sinuses are
Frontal and ethmoid - anterior cranial fossa
Maxillary - orbits
Sphenoid - optic nerve, internal carotid artery and cavernous sinus
Why are the anatomical relations of the paranasal sinuses clinically important?
Infections of sinuses can spread via anatomical relations to cause serious infection e.g. meningitis, intracranial abscess, orbital sepsis
Risks of sinus surgery are
CSF leak
Orbital complications
Blood supply and sensory innervation of maxillary sinus
Branches of internal maxillary artery
Branches of second division of trigeminal nerve, infraorbital nerve, greater palatine nerves
Blood supply and sensory innervation of frontal sinus
Supraorbital and supratrochlear arteries
Supraorbital and supratrochlear nerves (first division of trigeminal)
Blood supply and sensory innervation of sphenoid sinus
Sphenopalatine artery
Branches of first and second divisions of trigeminal nerve
Blood supply and sensory innervation of ethmoid sinus
Anterior and posterior ethmoidal arteries
Anterior and posterior ethmoidal nerves and orbital branches of pterygopalatine ganglion
Functions of paranasal sinuses
Vocal resonance
Decrease weight of skull and facial bones
Act as buffer for trauma
What is the epithelial lining of the nasopharynx?
Mucociliary
What are the boundaries of the nasopharynx?
Choana
Sphenoid sinuses
Prevertebral fascia and muscle
Soft palate
What are the important contents of the nasopharynx?
Eustachian openings and adenoids
What is a sinus ostium?
The opening that connects a sinus to the nasal cavity
What will blockage of a sinus ostia cause?
Accumulation of fluid in the sinuses
