Session 9 - The Nose

Question 1

What are the functions of the nose and nasal cavity?

Answer 1

Sense of smell
Provides a route for inspired air
Filters inspired air, trapping particle in nasal hair or mucous 
Moistens and warms inspired air
Resonating chamber for speech

Question 2

Inspired air enters the nasal cavity via what?

Answer 2

The vestibule

Question 3

What is the vestibule lined by?

Answer 3

Skin
Hair
Sebaceous glands

Question 4

Why are the nasal bones so common to fracture in facial injuries?

Answer 4

Because of the prominence of the nasal bones

Question 5

How is the pituitary gland accessed during pituitary surgery?

Answer 5

Through the nose and then through the sphenoid bone (trans-sphenoidal)

Question 6

What epithelium is found in the respiratory mucus membrane of the nasal cavity? How do the features of this epithelium allow the functions of the nasal cavity to be carried out?

Answer 6

Pseudostratified columnar ciliated epithelium:

• mucous/cilia - filters
• watery secretions - humidifies
• rich blood supply - warms inspired air

Question 7

Other than the respiratory mucus membrane, what other sort of mucous membrane is present in the nasal cavity?

Answer 7

Olfactory mucous membrane

Question 8

The mucous membranes in the nasal cavity receive drainage from where?

Answer 8

Paranasal sinus
Nasolacrimal duct (drains eye)

Question 9

What are the boundaries of the nasal cavity?

Answer 9

Floor - hard palate
Lateral wall - conchae and meatuses
Medial wall - nasal septum
Roof - frontal bone, cribriform plate (ethmoid bone), sphenoid bone

Question 10

What are the three bony projections in the lateral wall of the nasal cavity called?

Answer 10

Superior concha
Middle concha
Inferior concha

Question 11

Paranasal air sinuses and the nasolacrimal duct drain into what parts of the lateral wall of the nasal cavity?

Answer 11

Meatuses

Question 12

What is the function of the nasal conchae?

Answer 12

Slows airflow by causing turbulence

Increases the surface area over which air passes

Question 13

Where does the cartilaginous part of the nasal septum take its blood supply from?

Answer 13

The overlying perichondrium

Question 14

Explain how a septal haematoma may occur.

Answer 14

Trauma to the nose can lead to buckling of the nasal septum and steering of blood vessels.
Blood accumulates between the cartilage and the perichondrium, creating a septal haematoma

Question 15

If a septal haematoma is left untreated it may develop into what?

Answer 15

Saddle-nose deformity

Septal abscess

Question 16

Why does a saddle deformity occur in untreated septal haematomas?

Answer 16

Untreated septal haematoma leads to avascular necrosis of the cartilaginous septum. This therefore leads to saddling of the nasal dorsum.

Formation of a septal abscess will further increase the likelihood of avascular necrosis of the septum.

Question 17

Which cranial nerve carries general sensation from the nasal cavity?

Answer 17

Trigeminal (opthalmic and maxillary branches) (CN Va and Vb)

Question 18

What are nasal polyps?

Answer 18

Benign swellings of the nasal mucosa

Question 19

Describe the appearance of nasal polyps.

Answer 19

Swellings can either be pale or yellow in appearance, or may be fleshy and reddened.

Question 20

What are the symptoms of nasal polyps?

Answer 20

Blocked nose
Watery rhinorrhoea
Post-nasal drip
Decreased smell and reduced taste

Question 21

A unilateral nasal polyp with or without a blood tinged secretion is suggestive of what?

Answer 21

Tumour

Question 22

What is rhinitis?

Answer 22

Inflammation of the nasal mucosal lining

Question 23

What are the common causes of rhinitis?

Answer 23

The common cold (acute infective rhinitis)

Allergic rhinitis

Question 24

What are the symptoms of rhinitis?

Answer 24

Nasal congestion 
Rhinorrhoea (‘runnuy’ nose)
Sneezing 
Nasal irritation 
Postnasal drip

Question 25

What is the most common sauce of bleeding in epistaxis?

Answer 25

Kiesselbach’s plexus

Question 26

Arterial supply to the nasal cavity arises from branches of what two arteries?

Answer 26

Ophthalmic artery | Maxillary artery

Question 27

What blood vessels does venous blood from the nasal cavity drain into?

Answer 27

Pterygoid venous plexus Cavernous sinus Facial vein

Question 28

Epistaxis from what other artery is less common but potentially more serious and difficult to treat?

Answer 28

Sphenopalatine artery

Question 29

What are paranasal sinuses?

Answer 29

Air filled spaces that are extensions of the nasal cavity. Named according to the bone in which they are found.

Question 30

Paranasal sinuses are lined with what mucosa?

Answer 30

Respiratory mucosa (thus are also ciliated and secrete mucous)

Question 31

What is the purpose of paranasal air sinuses?

Answer 31

Help to humidify and warm inspired air. | Reduce weight of the skull.

Question 32

All paranasal sinuses drain into a meatus (mostly the middle meatus) via what channels?

Answer 32

Ostia

Question 33

What is sinusitis?

Answer 33

Infection of a sinus

Question 34

Which paranasal sinus is most commonly affected by sinusitis?

Answer 34

Maxillary

Question 35

What are the 4 paranasal sinuses called?

Answer 35

Frontal sinus Ethmoidal sinus Sphenoid sinus Maxillary sinus

Question 36

Roots of the upper teeth can sometimes project into which paranasal sinus?

Answer 36

Maxillary

Question 37

What is anther name for conchae?

Answer 37

Turbinates

Question 38

Which branches of the trigeminal nerve provide general sensory innervation to the paranasal sinuses?

Answer 38

Frontal, ethmoidal, sphenoid - ophthalmic (CN Va) | Maxillary - maxillary (CN Vb)

Question 39

Explain how rhinitis leads to sinusitis.

Answer 39

Primary infection (rhinitis) leads to reduced ciliary function, oedema of nasal mucosa and sinus ostia and increased nasal secretions. This impedes drainage from the sinus. Stagnant secretions within the sinus become an ideal breeding ground for bacteria, learning to the secondary infection (sinusitis).

Question 40

What does the nasal septum consist of?

Answer 40

Perpendicular plate of the ethmoid bone Septal cartilage Vomer

Question 41

How would acute sinusitis present?

Answer 41

Pain and tenderness over the sinus involved Nasal discharge General systemic upset (fever, feeling unwell)

Question 42

What are the causes of sinusitis?

Answer 42

``` Infections of the nose (rhinitis, upper respiratory tract infections) Dental infections (roots of some upper teeth can lie in the floor of the maxillary sinus) ```

Question 43

Give a rare complication of ethmoidal sinusitis.

Answer 43

Orbital cellulitis - this is potentially sight-threatening as could involve optic nerve or even track further back to involve intracranial structures.

Question 44

Why is the maxillary sinus most commonly affected by sinusitis?

Answer 44

The maxillary sinus drains poorly because the ostium sits high up the wall of the sinus, meaning it has to drain upwards.