nasal cavity Flashcards
what are the functions of the nasal cavity
- sense of smell
- warms and moistens air
- helps speech
what is the external nose made up of
mostly cartilaginous but also bone (nasal bone and maxilla)
what is the vestibule in the nose
where the air flows into from the nostrils in the external nose
how is the superior part of the nasal cavity different
its lined with olfactory mucus membrane - this contains receptors for the olfactory nerve so is where smell is sensed
what is the roof of the nasal cavity
ethmoid bone (cribiform plate) and frontal bone
what is the medial wall of the nasal cavity
the nasal septum - cartilaginous and also bony (ethmoid, vomor bone and sphenoid bone)
what is the lateral wall of the nasal cavity
maxilla
what is the floor of the nasal cavity
hard palate
what happens to the movement of air when it enters the nasal cavity
it slows down
what causes a slower movement of air in the nasal cavity
- movement into a bigger area
- turbulent air flow set up by the conchae
what are the conchae in the nasal cavities
bony projections lined by the mucus membrane
what are the spaces between the conchae called
meatus
what epithelia lines the nasal cavity
pseudo stratified columnar ciliated
what do the conchae in the nose do
- slows air down by creating turbulent blood flow
- increases the SA of the nasal cavity
what sinuses drain into the nasal cavity and where in the cavity do they drain
- paranasal and nasolacrimal duct
- drain into the metauses
what are the role of the sinuses
humidify and warm inspired air
reduce the weight of the skull
what is the innervation to the paranasal sinuses
frontal, ethmoid and sphenoid = ophthalmic
maxillary = maxillary
what are the names of the 4 paranasal sinuses
frontal, ethmoid, sphenoid and maxillary
why does sinusitis most commonly occur in the maxillary sinus
as the drainage is higher up in the sinus wall, making it harder to drain into the nasal cavity so stasis can occur easily
why does sinusitis involving the maxillary sinus cause tooth pain
the teeth and the maxillary sinus share a nerve supply (maxillary)
where can infection in the ethmoid sinuses potentially spread to
orbits
what nerves supply sensation to the nose
maxillary and ophthalmic branches of the trigeminal nerve
where is the blood supply to the nose from
ophthalmic and maxillary arteries
what is the most common type of nose bleed
anterior nose bleed - where the anatomoses in the cartilage of the nasal septum bleed
what blood vessel causes posterior nose bleeds
sphenopalatine artery
where does the venous drainage of the nose go
pterygoid plexus - cavernous sinus - facial vein
how can a basilar skull fracture cause CSF leakage from the nose
can damage the crista Galli - the falx cerebri is attached to this so can rip the dura and cause CSF to fall into the nasal cavity
what is a septal haematoma
where trauma to the nose separates the perichondrium overlying the cartilage of the nasal septum and blood accumulates in this space
what happens to an untreated haematoma
saddle deformity due to avascular necrosis
what are nasal polyps
benign growths in the nasal cavity from the mucosa
what symptoms do nasal polyps give
reduced smell, reduced taste, watery rhinorrhoea, blocked nose
what is rhinitis
inflammation of the nasal mucosal lining
what is sinusitis
inflammation of the lining of the sinus
how does an infection in the nasal cavity cause sinusitis
the infection causes reduced ciliary function, mucosal oedema and increased nasal secretions - this impedes drainage of the sinuses so theres stasis leading to infection
