Lecture 15 - Nasal Cavity And Paranasal Sinuses Flashcards
What are the functions of the nasal cavity?
Olfaction
Warm/humidify air
Filter particles/trap incoming particles
Route for incoming air
Resonating chamber for speech
What is the medical term for the nostrils?
Nares
What is the structure marking the end of the nasal cavity and start of nasopharynx?
Choanae
What important structure related to the ear is located in the nasopharynx?
Eustachian tube
What are the 3 main regions of the nasal cavity?
Vestibule
Respiratory region
Olfactory region
What is the function of the vestibule region of the nasal cavity?
What cells does it contain?
Filters particles entering the nasal cavity
Stratified squamous epithelium
What cells line the respiratory region of the nasal cavity?
Ciliated Pseudostratified epithelium
Goblet cells
What is contained in the olfactory region of the nasal cavity?
Olfactory nerves penetrating through the cirbiform foramina through the cribiform plate
Go to the last slide and label the regions of the nasal cavity:
1 = olfactory region
2 = respiratory region
3 = vestibule
4 = nasopharynx
What bones form the roof of the nasal cavity?
Frontal bone
Ethmoid bone
Sphenoid bone
Nasal bone
What bones form the floor of the nasal cavity?
Palatine bone
Maxillary bone
Go to the last slide and label the bones of the nasal cavity:
Image 2
1 = nasal bone
2 = frontal sinus
3 = ethmoid bone
4 = sphenoid bone
5 = maxilla bone
6 = palatine Bone
What bone forms the lateral wall of teh nasal cavity?
Ethmoid bone
What are the structures that slow down air flow in the nasal cavity?
Concha
What bone do the 3 concha come from?
Ethmoid bone
What are the 3 concha of the ethmoid bone?
Superior concha
Middle concha
Inferior concha
What are the functions of the concha?
Slow down air flow
Increase the surface area of the nasal cavity
What are the structures that are associated with each concha called?
Meatuses
What are the functions of the superior, middle and inferior meatus?
Drainage
They connect to paranasal air sinuses + nasolacrimal ducts
Go to the last slide and label the image labelled 3:
1 = superior concha
2 = middle concha
3 = inferior concha
4 = superior meatus
5 = middle meatus
6 = inferior meatus
What forms the medial wall of the nasal cavity?
Ethmoid bone -> septal cartilage (septal cartilage is continous with the ethmoid bone)
Vomer bone
What causes a septal haemotoma?
Trauma to the cartilage leads to the perichondrium becoming sheared off
Avascular necrosis of the cartilage then occurs since the cartilage relies on the perichondrial layer for blood
What deformity does a septal haemotoma lead to?
Saddle nose deformity
How is a septal haemotoma treated?
Drain the blood to prevent development of infections/abcesses
Repack the cartilage and perichondrium back together
What part of the nose made of septal cartilage gets affected in saddle deformity?
Dorsum (undergoes Avascular necrosis)
How does a nasal bone fracture present?
What are 2 rare complications?
Lots of swelling
Epistaxis
CSF leak
Anosmia
Why cannn a nasal bone fracture lead to anosmia?
The olfactory nerves travelling through the cribiform foramina can get sheared
What are the advantages of the nasal cavity having a rich blood supply?
Allows for the humidifcation of air
How many arteries supply the medial wall of the nasal cavity?
5
What are the 5 arteries that supply blood to the medial wall of the nasal cavity?
Anterior ethmoidal artery
Posterior ethmoidal artery
Sphenopalatine artery
Greater palatine artery
Superior labial/septal artery
What is the name given to the area where all 5 arteries anastomose in the nasal cavity?
Littles area
Go to the last slide and label image 4 of all the arteries of the medial wall of the nasal cavity:
1 = anterior and posterior ethmoidal arteries
2 = sphenopalatine artery
3 = greater palatine artery
4 = superior labial artery
5 = littles area
What is the most common area for epistaxis in the nasal cavity and why?
Littles area
Where all 5 arteris supplying the medial nasal cavity wall anastomoses
What artery is damaged in a posterior nose bleed?
Why is it dangerous?
Sphenopalatine artery
Blood can drip down throat and through both nostrils
What are the 3 arteries that supply the lateral wall of the nasal cavity?
Anterior ethmoidal artery
Posterior ethmoidal artery
Sphenopalatine artery
The anterior and posterior ethmoidal arteris branch from the ophthalmic arteries,
What blood vessel is the ophthalmic artery a branch of?
Internal carotid artery
The sphenopalatine artery and greater palatine arteries are branches of the maxillary arerty,
What blood vessel is the maxillary artery a branch of?
External carotid artery
What artery does the anterior and posterior ethmoidal arteries arise from?
Ophthalmic artery
What artery do the Sphenopalatine and greater palatine artery branch from?
Maxillary artery
What cranial nerve is responsible for sensation to the nose/nasal cavity?
Trigeminal nerve
What branch of the Trigeminal nerve does the tip of the nose and anterior part of nasal cavity?
What branch of the Trigeminal nerve does the posterior part of the nasal cavity?
Tip = ophthalmic division of Trigeminal
Posterior nasal cavity = maxillary division of Trigeminal
What are nasal polyps?
Benign swellings int he nasal mucosa
How do nasal polys present?
> 40yrs
More male
Normally bilateral
Nasal congestion
Rhinorrhea
Hypo or anosmia
Snoring
Post nasal drip
What is post nasal drip?
Rhinorrhea drip down from teh nasopharynx to oropharynx to the larynx which irritates the vocal cords
What genetic condition are nasal polyps common in?
Cystic fibrosis
What are red flags that suggest a nasal polyp may actually be nasal cancer?
Unilateral polyp
Bloody discharge
What is Rhinitis?
Inflammation of the nasal mucosa
What are some symptoms of rhinitis?
Nasal congestion
Rhinorrhea
Sneezing
Post nasal drip
Nasal irritation
How does the h treatment for infective rhinitis differ to allergic rhinitis?
Infective = conservative
Allergic = Intra nasal antihistamines and maybe intranasal steroids
What is the likely diagnosis for this child:
Summers day
6yr old
1 week Hx runny nose
Discharge from R nostril
Last few days discharge smelly and blood stained
Other wise well
1 = infective rhinitis
2 = nasal cancer
3 = foreign body
4 = allergic rhinitis
5 = nasal polyp
- Foreign body
1 would be bilateral
2 is to young and symptoms are acute
4 the blood not common
5 is benign so would have blood
What are paranasal air sinuses?
Air filled spaces that are extensions of the nasal cavity
What cells line the paranasal air sinuses?
Respiratory mucosae
Pseudostratified Ciliated epithelium
Goblet cells
What is a nasal cavity infection involving sinuses called?
Sinusitis
What are the functions of the paranasal air sinuses?
Humidify and warm inspired air
Reduce weight of skull
What are the names of the small channels which drain the sinuses back into the nasal cavity through 1 of the meatuses?
Ostia
What is the most commonly affected paranasal air sinus in sinusitis?
Maxillary sinus
Why is the maxillary air sinus the most commonly affected in sinusitis?
It’s Ostia drain the highest meaning theres a longer distance for contents to drain through
Go to the last slide and label the sinuses:
Image 5
1 = frontal sinus
2 = ethmoid sinus
3 = nasal cavity
4 = maxillary sinus
5 = sphenoid sinus
6 = pharynx
What is the main meatus through which most of the paranasal air sinuses drain through?
Middle meatus
What paranasal air sinuses does the middle meatus drain into the nasal cavity?
Frontal sinus
Maxillary sinus
Anterior and middle ethmoid sinus
What does the inferior meatus drain into the nasal cavity/
NASOLACRIMAL duct
What does the roof of the nasal cavity drain
Sphenoid sinus
What nerve supplies sensation to the frontal, ethmoidal and sphenoid sinus?
Ophthalmic division of the Trigeminal nerve
What nerve supplies sensation to the maxillary sinus?
Maxillary division of the Trigeminal nerve
Go to the last slide and label the paranasal air sinuses on image 6:
1 = frontal sinus
2 = orbit
3 = maxillary sinus
4 = frontal sinus
5 = sphenoid sinus
Go to the last slide and label image 7:
1 = middle and inferior meatus
2 = middle and inferior conchae
3 = maxillary air sinus
What is acute sinusitis?
Where a viral upper respiratory tract infection spreads to the sinuses
Resolves in less than 12wks
What is the pathophysiology of acute sinusitis?
Inflammation of resp mucosa causes swelling reduced cilia movement of mucus and increased mucus production
Ostia get blocked
Fluid builds up in sinus
Secondary bacterial infection can occur
Why aren’t Abx usually given with acute sinusitis?
Mostly caused by virus
Only a small amount of people develop secondary bacterial sinusitis
How does a patient usually present who has acute sinusitis?
Recent URTI
Blocked nose and Rhinorrhea with green/yellow discharge
Pyrexia
Headache /facial pain in affectd area
Facial pain gets worse leaning forward
How does acute bacterial sinusitis present?
Symptoms for over 10days of acute sinusitis without improvement
Discoloured/purulent nasal discharge
Fever >38
Severe local pain
Symptoms that worsen after initial improvement
What are some causative organisms for acute bacterial sinusitis?
HSM (High School Musical)
Streptococcus pneumonia
Haemophilus influenzae
Moraxella catarrhalis
Organisms that can cause pneumonia
How do you manage someone with a massive nosebleed?
Clamp the tip of the nose
Cauterise the blood vessels
Put head forwards to prevent swallowing
Nasal tampons
What signs are often seen in a patient with a base of skull fracture like the ethmoid bone?
Periorbital ecchymosis
Halo sign
What is the halo sign seen in base of skull fractures?
When there’s Rhinorrhea containing both blood and CSF
What nerve moves the soft palate?
Vagus nerve
What nerves are important in the gag reflex?
Glossopharyngeal
Vagus
