H&N 8.1- the nose and paranasal sinus' Flashcards
What are the main functions of the nose and nasal cavity?
- sense of smell
- route for air to get from the atmosphere into the lungs
- warms and humidifies inspired air
- filters inspired air (nasal hair and mucus)
- resonating chamber for speech
Why does your mouth get dry when you breath through your mouth?
It is not designed to warm and moisten the air like the nose is, so the air dries the mouth out.
What different structures are found in the nasal area?
- external nose
- nasal cavity
- nasopharynx
What is the external nose made of?
cartilage and bone
What are the features of the external nose?
- the root (the bony part of the nose between the eyes)
- the bridge (the point at which the bone becomes cartilage)
- the tip/apex.
- the nares/nostrils
What bones contribute to the external nose?
- nasal bone
- frontal part of maxilla
Why are broken noses common?
The external nose is prominent so susceptible to trauma
How do you treat a broken nose?
- sometimes just left to heal on their own
- if there a deviated midline then surgery may be required to reallign the nose (only after swelling has gone down)
If someone has a broken nose, what must you bear in mind?
They will have experienced trauma, so there is also the risk of head injuries and neck injuries which need to be considered.
How can you further divide the nasal cavity?
- Vestibule- Just surrounding the external opening to the nasal cavity
- respiratory region- where the air travels, it is lined with pseudostratified clilliated mucosa which has goblet cells.
- olfactory region- located at apex, contains the olfactory receptors
What are the boundaries of the nasal cavity?
- superior- ethmoid bone (cribriform plate, crista galli), frontal bone, nasal bone, sphenoid bone
- lateral- maxilla and conchae
- medial- nasal septum
- floor- hard palate and soft palate
What is the nasal septum made from?
- the perpendicular plate of the cribriform plate
- vomer
- septal cartilage.
What makes up the hard palate?
-the palatine bones and the palatine process’ of the maxilla.
What lies immediately superior to the nasal cavity?
What is the significance of this?
The anterior cranial fossa, which is attached to the crista galli via the falx cerebri,
Trauma to the nose can cause tearing of the falx cerebri, resulting in cerebral rhinorrhoea.
This could later result in an increased risk for meningitis/brain abcess.
What is a septal haematoma?
Can result after trauma to the nose, where there is a build up of blood between the perichondrium and cartilage.
What symptoms would someone with haematoma present with?
feelings of a blocked nose
painful swelling
congestion
change in the shape of the nose
What complications can arise from a septal haematoma and why do these develop?
Saddle-nose deformity.
The cartilage normally get’s its blood supply from the overlying perichondrium, so when this is stripped away the cartilage undergoes avascular necrosis, and the septum can loose it’s shape resulting in a concave appearance.
infection within the heamatoma due to stasis.
How would you treat a septal haematoma?
drain the blood from it and pack the nose, to push the 2 layers (perichondrium and cartilage) back together, to stop blood from building up between them again and to return blood supply to the cartilage.
What are conchae and what is their function?
bony projections on the lateral walls of the nasal cavity.
They act to increase surface area, to air with warming and humidifying inspired air and slowing the flow.
What is found beneath each conchae?
a corresponding meatus (here are where drainage from the paranasal sinus’ and the nasolacrimal duct occurs)
What is the spheno-ethmoidal recess?
The area above the superior concha, therefore it is not a meatus.
The sphenoid sinus drains here.
What appearance does the nasal mucosa have?
Very pink
you see this when looking up the nose, before the nasal mucosa you’ll see skin coloured epithelia and hairs.
What membranes are found within the nasal cavity?
- olfactory mucus membrane (allow us to smell)
- respiratory mucus membrane (allow air to slow, warm and become humidified)
what nerve innervates the sensation of the nasal cavity?
The trigeminal nerve
superior anterior-opthalmic branch
(inferior posterior- maxillary branch)
What is a nasal polyp?
A benign fleshy swelling found within the nose which come from nasal mucosa.
- often bilateral
- often occur in people >40
- pale/yellow in appearance or fleshy and redenned.
What symptoms might someone with a polyp complain of?
- a blocked nose
- decreased smell and reduced taste
- post-nasal drip (causing a tickly cough)
- rhinorrhoea (runny nose)
When might you be concerned about a polyp?
When it’s unilateral / blood tinged/ in young people.
How could you determine between a concha or a polyp?
- a polyp will be paler in colour, mobile, and not hurt when touched.
- a concha will be pinker, be immobile and if poked will hurt.
What is rhinitis?
inflammation of the mucosal lining.
What is the most common cause of rhinitis?
actute infective rhinitis (the common cold, viral)
Could also be allergic rhinitis.
What symptoms do you get with rhinitis and why?
- rhinorrhoea (inflammed mucosa produces more secretions)
- tickly coigh (these secretions trickle down the back of the throat)
- sneezing
- blocked nose (inflammed mucosa, especially over concha which already stick out, impeed airflow)
Other than rhinitis, what other causes could lead to a runny nose?
- polyp
- forreign body
- cancer of the nose
What is the medical term for a nose bleed?
epistaxis
From what arteries does the blood supply from the nose come from?
- opthalmic artery (From ICA)
- Maxillary artery (from ECA)
What is the rich anastomes area better known as?
What’s the significance of this area?
Kiesselbachs area/Littles area.
it’s a common site of epistaxis.
What 5 arterial branches supply the nose?
- Anterior ethmoid
- posterior ethmoid
- sphenopallatine
- Greater pallatine
- superior labial
What should you do in a simple case of epistaxis and why?
-pinch the bridge of hte nose, this is proximal to kiesselbachs area, so will reduce blood flow to there, reducing the bleeding of the nose. (which often comes from this area)
What are the names of the paranasal sinus’?
- frontal sinus
- ethmoid sinus
- sphenoid sinus
- maxillary sinus
What is the function of the paranasal sinus?
To help to humidify and warm inspired air (lined by respiratory mucosa)
To reduce the weight of the skull
Where do the paranasal sinus’ drain?
frontal sinus'- middle meatus
sphenoid sinus- sphenoidethmoidal recess
ethmoid- anterior-superior meatus
-middle- superior meatus
- posteior- middle meatus
Maxillary sinus-middle meatusWhat drains into the inferior meatus?
The naso-lacrimal duct
What are the important clinical relations of the paranasal sinus?
ethmoid air cells- orbit
frontal sinus- anterior cranial fossa
maxillary sinus can somtimes communicate to the roots of the upper teeth
What is sinusitis?
What are it’s causes?
acute Inflammation of the paranasal sinus’
(mostly infective and mostly due to secondary viral infection)
The inflammation of the mucosa reduce cilliary function, and make drainage of the sinus’ impaired. this promotes infection.
Could be due to blockage of the ostia- eg a polyp, deviated septum.
What symptoms does sinusitis cause?
Painful sinus’ and headaches which intensify upon leaning forward
pyrexia
blocked nose
rhinorrhoea (May have purulent discharge)
non resolving cold
Which sinus is most commonly affected in sinusitis and why?
Maxillary sinus, it’s drainage is quite superior so often collections of fluid can gather at the bottom of the sinus, which promotes infection
What is the treatment for sinusitis?
Often it is self limiting so you may advise to give decongestants or pain releif but wont give specific medications (only supportive)
If chronic (>4 weeks) or severe will prescribe antibiotics.
What are some common bacterial causes of sinusitis?
streptococci
Haemophillus.
What is the neural innervation of the paranasal sinus?
All innervated by the opthalmic nerve, except the maxillary sinus’ which are innervated by the maxillary nerve.
What is the clinical significance of the spenoid sinus?
It can be used to access the pituitary gland during surgery.
insertion of surgical tools up the nasal cavity, through the nasal roof and the sphenoid sinus to the pituitary gland.
Why might sinusitis result in toothache?
The maxillary sinus is most commonly affected, and is supplied by the maxillary nerve, which also innervates the maxillary teeth.
Therefore, pain can be percieved as coming from the teeth.
Where does the auditory tube open into?
The nasopharynx at the level of the inferior meatus.
What is the venous drainage of the nose?
Facial vein, pterygoid plexus or cavernous sinus.
What are some causes of epistaxis?
local- such as trauma
systemic-such as hypertension,
