9.2 The Nasal Cavity & Paranasal Air Sinuses

Question 1

What are the 5 functions of the nasal cavity?

Answer 1

• Sense of smell
• Resonating chamber for speech
• Warms and humidifies air
• Route for air into the lungs
• Traps and filters particles

Question 2

What is the structure of the nasal cavity?

Answer 2

Medial wall (nasal septum)
2 lateral walls
Roof
Floor

Question 3

What is the entrance to the nose called? (nostrils)

Answer 3

Nares

Question 4

What is the region called where the nasopharynx opens into the oropharynx?

Answer 4

Choanae

Question 5

What are the 3 regions of the nasal cavity?

Answer 5

Vestibule- skin (stratified squamous keratinised epithelia)

Respiratory- pseudostratified ciliated columnar epithelium

Olfactory- sense of smell

Question 6

What bones contribute to the roof of the nasal cavity?

Answer 6

Nasal
Frontal
Ethmoid
Sphenoid

Question 7

What bones contribute to the floor of the nasal cavity?

Answer 7

Maxilla
Palatine

Question 8

Why are the lateral walls of the nasal cavity irregular?

Answer 8

Concha (turbinates) slow down air flow
Increase surface area

Question 9

What bone makes up the superior and middle conchae?

Answer 9

Ethmoid bone

Question 10

How many meatuses are there in the nasal cavity and what do they do?

Answer 10

Superior, middle and inferior
Responsible for drainage, connections with paransal sinuses and nasolacrimal duct

Question 11

What happens to size of the conchae as you move downwards?

Answer 11

Become larger

Question 12

What does the medial wall of the nasal cavity consist of?

Answer 12

Perpendicular plate of the ethmoid bone
Vomer bone
Septal cartilage

Question 13

How do you access the pituitary gland surgically?

Answer 13

Transphenoidal surgery, through the sphenoid sinus

Question 14

What is a septal haematoma?

Answer 14

Trauma to cartilage causes the perichondrium to be stripped off

Blood then accumulates between the cartilage and periochondrium

Question 15

What can happen if a septal haematoma is not treated?

Answer 15

Can lead to avascular necrosis causing saddle nose deformity

Question 16

How do you treat a septal haematoma?

Answer 16

Blood accumulation needs to be drained and then packed to prevent further accumulation of blood between perichondrium and cartilage

Question 17

What cartilage is present on the nose?

Answer 17

Septal cartilage
Lateral
Major alar
Minor alar
Fibro-fatty tissue

Question 18

What bones contribute to the lateral nose?

Answer 18

Maxilla
Nasal bone

Question 19

What are the 3 parts of the nose?

Answer 19

Bridge
Dorsum
Tip

Question 20

How common are nasal bone fractures?

Answer 20

Account for 50% of all facial fractures, protrudes and not particularly strong

Question 21

What is visible in a nasal bone fracture?

Answer 21

Lots of swelling
Epistaxis

Question 22

How do you treat a nasal bone fracture?

Answer 22

X-rays generally not needed as doesn’t change treatment
Follow up in several days in outpatient once swelling has settled

Nose may need to be reset if there are breathing issues

Rare complications can result in CSF leak and anosmia

Question 23

Why is there a rich blood supply to the nasal cavity?

Answer 23

Allows the nose to humidify and warm incoming air

Question 24

What is the most common site of epistaxis?

Answer 24

Kiesselbach’s area/Littles
All of the blood vessels join at this area

Question 25

What are the blood vessels supplying the nasal cavity?

Answer 25

Anterior and posterior ethmoidal arteries- branches of the opthalmic artery ICA branch 1 Sphenopalatine artery Greater palatine artery (both branches of the maxillary artery, terminal branches of ECA) Superior labial artery (septal branch)

Question 26

How do you approach a nose bleed?

Answer 26

1. Get patient to lean forwards and hold nose for 10-15 minutes, should hopefully clot if its an anterior bleed 2. Next try cauterising the bleed using silver nitrate strips 3. Try anterior packing of the nose 4. Finally try posterior packing of the nose 5. Call ENT may need surgery to repair especially if posterior bleed

Question 27

What vessel is responsible for posterior nose bleeds?

Answer 27

Sphenopalatine artery, difficulty to stop have to try posterior packing, may have blood drip down into mouth

Question 28

What is responsible for anterior nose bleeds?

Answer 28

Little's/ Kiesselbach's area

Question 29

What is the sensory nerve supply to the nasal cavity?

Answer 29

Trigemnial nerve, opthalmic and maxillary branch

Question 30

What are nasal polyps?

Answer 30

Benign swellings of the nasal mucosa

Question 31

Who is affected by nasal polyps?

Answer 31

M:F 2:1 40< year olds In children suggestive of cystic fibrosis Normally bilateral

Question 32

What do patients with nasal polyps experience?

Answer 32

Nasal congestion Rhinorrhea- runny nose Hypo- or anosmia Snoring Post nasal drip, causing a cough

Question 33

What are red flags of nasal polyps?

Answer 33

Unilateral polyp Bloody discharge May be indicative of nasal cancer

Question 34

How do you treat nasal polyps?

Answer 34

Intranasal steroids

Question 35

What is rhinitis?

Answer 35

Inflammation of the nasal mucosa

Question 36

What are the two causes of rhinitis?

Answer 36

Infective- usually viral, use pain management and nasal sprays Allergic- hayfever, animal hair etc. use antihistamines

Question 37

What are the symptoms of rhinitis?

Answer 37

Nasal congestion Rhinorrhea Sneezing Post-nasal drip Nasal irritation

Question 38

What is a common cause of unilateral bloody discharge from the nose in a child?

Answer 38

Foreign body

Question 39

What are paranasal air sinuses?

Answer 39

Air-filled spaces that are extensions of nasal cavity Drain into meatuses via small channels (ostia)

Question 40

What epithelium lines the paranasal sinuses?

Answer 40

Extension of nasal cavity, therefore respiratory mucosa, thus ciliated and secrete mucous

Question 41

Why do infections of the nasal cavity affect the sinuses?

Answer 41

Sinuses are connected to the nasal cavity therefore can be involved, leading to sinusitis Maxillary sinus is the most common sinus as the ostia are high up therefore mucous cannot drain easily and it becomes stagnant

Question 42

What do paranasal air sinuses do?

Answer 42

Humidify and warm inspired air Reduce weight of the skull

Question 43

What are the different paranasal air sinuses?

Answer 43

Frontal sinus Ethmoid sinus Maxillary sinus Sphenoid sinus

Question 44

What sinuses drain into the middle meatus?

Answer 44

Frontal Maxillary Anterior ethmoid

Question 45

What sinuses drain into the inferior meatus?

Answer 45

Nasolacrimal duct- tears

Question 46

What sinus drains into the roof?

Answer 46

Sphenoid sinus

Question 47

What sinuses recieve general sensory innervation from CNVa?

Answer 47

Frontal Ethmoidal Sphenoidal

Question 48

What sinuses recieve general sensory innervation from CNVb?

Answer 48

Maxillary

Question 49

Label the image

Answer 49

Question 50

Paranasal air sinus image

Answer 50

Question 51

What is acute sinusitis?

Answer 51

Inflammation of paranasal air sinuses caused by URTI

Question 52

What is the pathophysiology of acute sinusitis?

Answer 52

Inflammation of respiratory mucosa causes swelling, reduced cilia movement and increased secretions Ostia become blocked , sinus cannot drain mucous builds up in sinus causing increased pressure and pain Can develop secondary bacterial infection

Question 53

How long does sinusitis have to be to be acute?

Answer 53

Less than 4 weeks, normally resolves within 10 days

Question 54

What is clinical diagnosis of acute sinusitis based on?

Answer 54

Recent URTI Blocked nose and rhinorrhoea, may have green or yellow discharge Pyrexia Headache/ facial pain, in area of affected sinus, worse on leaning forward

Question 55

How is acute sinusitis managed?

Answer 55

Conservatively, mostly viral cause, use painkillers etc. 0.5-2% may develop bacterial sinusitis

Question 56

When is acute bacterial sinusitis the more likely diagnosis?

Answer 56

Symptoms particularly severe at onset Symptoms lasts longer than 10 days, but less than 4 weeks **Symptoms that worsen after initial improvement, suggesting secondary bacterial infection**

Question 57

What bacteria cause bacterial sinusitis?

Answer 57

Steptococcus pneumoniae Haemophilus influenzae Moraxella catarrhalis