9 - Nose

Question 1

What are the functions of the nose/nasal cavity?

Answer 1

Olfaction 
Route for inspired air
Filtration of inspired air - trapping particles in nasal hair /mucous
Moistens and warms inspired air
Resonating chamber for speech

Question 2

How does inspired air enter the nose?

Answer 2

Via the vestibule

Question 3

Describe the structure of the external nose

Answer 3

Cartilaginous tip

Perimeter of bone, bridge - nasal bone, sides- frontal process of maxillary

Question 4

What are the divisions of the nasal cavity?

Answer 4

Vestibule
Respiratory region
Olfactory region

Question 5

Describe the olfactory region of the nasal cavity

Answer 5

Apex of nasal cavity

Lined with olfactory mucous membrane, with olfactory (I) receptors

Question 6

Describe the respiratory region of the nasal cavity

Answer 6

Majority of nasal cavity

Pseudostratified columnar ciliated epithelium interspersed with goblet cells

Question 7

What is the function of the respiratory region and how does it achieve this?

Answer 7

Filters inspired air - goblet cells and cilia
Humidifies - watery secretions
Warms - rich blood supply

Question 8

What drains into the nasal cavity?

Answer 8

Paranasal sinuses

Nasolacrimal duct - why nose runs when you cry

Question 9

What are conchae and what are their function?

Answer 9

Curved shelves of bone - superior, middle and inferior
Increase surface area and disrupt fast laminar flow of air, making it more turbulent so it spends longer in nasal cavity, allowing it to be humidified

Question 10

What are the nasal meatuses?

Answer 10

Spaces where paranasal air sinuses and nasolacrimal ducts drain

Question 11

What forms the roof of the nasal cavity?

Answer 11

Frontal bone
Ethmoid + cribiform plate
Sphenoid bone

Question 12

What causes a septal haematoma?

Answer 12

Cartlaginous part of septum takes blood from perichondrium
Trauma to nose leads to buckling of septum and shearing of blood vessels
Blood accumulates between perichondrium and cartilage, causes swelling

Question 13

What is a saddle-nose deformity?

Answer 13

Untreated septal haematoma leading to avascular necrosis of cartilaginous septum
Infection can develop from collecting haematoma, leading to septal abscess

Question 14

What cranial nerve carries sensation from the nasal cavity?

Answer 14

Trigeminal - maxillary mostly (V2)

Question 15

What are nasal polyps and what symptoms does it present with?

Answer 15

Benign swellings of nasal mucosa, usually bilateral 
Symptoms:
Decreased ability to smell and taste 
Post nasal drip 
Blocked nose
Watery rhinorrhoea

Question 16

How are nasal polyps distinguished from nasal tumours?

Answer 16

Tumours: Unilateral, blood tinged secretions
Polyps: Bilateral, watery secretions

Question 17

What is rhinitis and what symptoms does it present with?

Answer 17

Inflammation of the nasal mucosal lining

Symptoms: Nasal congesition, rhinorrhoea, postnasal drip

Question 18

What signs would suggest a foreign body in nasal cavity?

Answer 18

Discharge from one nostril
Smelly, blood stained discharge
Otherwise fine
Child

Question 19

Describe the blood supply to the nose

Answer 19

Arterial: Opthalmic and maxillary arteries, sphenopalatine artery
Venous: Pterygoid venus plexus, cavernous sinus and facial vein

Question 20

What is Kiesselbach’s plexus?

Answer 20

Anastomoses in anterior septum - common source of bleeding in epistaxis

Question 21

What makes epistaxis more serious and why?

Answer 21

Bleeding from sphenopalatine artery, can’t be compressed as is at back of nasal cavity

Question 22

What are the paranasal sinuses?

Answer 22

Air filled, extensions of nasal cavity - frontal, ethmoid, sphenoid, maxillary
Lined with respiratory mucosa to humidify and warm inspired air, also reduce weight of the skull

Question 23

Where do the paranasal sinuses drain?

Answer 23

Into nasal cavity via ostia into a meatus, mostly middle meatus

Question 24

Describe the innervation of the paranasal sinuses

Answer 24

Frontal, ethmoidal and sphenoid - opthalmic (V1) and maxillary (V2)
Maxillary sinus - maxillary nerve (V2)

Question 25

What is acute sinusitis?

Answer 25

Acute inflammation of lining of sinus, often secondary to viral infection of nasal cavity

Question 26

What are the presenting symptoms of acute sinusitis?

Answer 26

Non-resolving cold
Pyrexia
Blocked nose and rhinorrhoea with green discharge
Facial pain in affected sinus, worse leaning forwards

Question 27

Describe the pathophysiology of acute sinusitis

Answer 27

Primary infection (rhinitis) leads to reduced ciliary function, oedema of nasal mucosa and sinus ostia becomes blocked
Stagnant secretions within sinus become ideal breeding ground for secondary infection