Nasal Cavities and Paranasal Sinuses

Question 1

List the parts of the external nose

Answer 1

Root
Dorsum
Apex (tip)
Ala (wings)
Nares (nostrils)
Septum
Philtrum (upper lip)

Question 2

State the two main types of tissue making up the nose

Answer 2

Nasal bone

Hyaline cartilage

Question 3

State the investigation of choice for nasal fracture

Answer 3

No investigation

Question 4

What forms the roof and floor of the nasal cavity respectively?

Answer 4

Cribiform plate and crista galli (anterior cranial fossa)

Palate

Question 5

What forms the lateral wall of the nasal cavity?

Answer 5

Superior and middle conchae
Air cells
Orbital plate of ethmoid
Inferior conchae

Question 6

What forms the septum of the nasal cavity?

Answer 6

Perpendicular plate of ethmoid
Vomer
Septalhyaline cartilage

Question 7

Le Forte fractures 2 and 3 disrupt which part of the ethmoid?

Answer 7

Cribiform plate of ethmoid

Question 8

What is the consequence of Le Forte Fractures?

Answer 8

Danger of infection spreading from nasal cavity and paranasal sinuses into anterior cranial fossa (cribiform plate and dura are only protection)

Question 9

List the types of mucosa in the nasal cavity

Answer 9

Keratinised SSE
Respiratory epithelium
Olfactory mucosa

Question 10

Outline the neurone chain of the olfactory nerve starting at receptors

Answer 10

Receptor cells 1ST NEURONE –>
Cribiform plate of ethmoid in olfactory mucosa –>
Olfactory bulb (ganglion) 2ND NEURONE –>
Olfactory tract –>
Temporal lobe

Question 11

The trigeminal nerve supplies sensory innervation to the nasal cavity. State the area supplied by each of it’s branches

Answer 11

V1: Anterosuperiorly
V2: Posteroinferiorly

Question 12

Outline the area of the nasal cavity supplied by the external carotid artery, and give branches in order

Answer 12

EXTERNAL CAROTID

1. Facial artery –> lateral nasal branch (lateral wall) and septal branch of superior labial artery (medial wall)
2. Maxillary artery –> sphenopalatine (medial and lateral wall) and greater palatine arteries (medial wall)

Question 13

Outline the area of the nasal cavity supplied by the internal carotid artery, and give branches in order

Answer 13

INTERNAL CAROTID

Ophthalmic artery –> anterior and posterior ethmoidal arteries (medial and lateral wall)

Question 14

What is the significance of Kiesselbach (Little’s) area

Answer 14

Arterial anastomosis on nasal septum which is a common site for epistaxis

Question 15

The conchae of the nasal cavity are all made up of one bone. True/ False?

Answer 15

False

Inferior conchae is it’s own bone, superior and middle conchae are one bone

Question 16

State the name for the space under each conchae

Answer 16

Meatus

Question 17

List the meatuses of the nasal cavity from superior to inferior

Answer 17

Sphenoethmoidal recess
Superior meatus
Middle meatus
Inferior meatus

Question 18

How does a correctly placed nasogastric tube appear on imaging?

Answer 18

In midline to level of diaphragm

Tip should be visible 10cm beyond GOJ (in stomach)

Question 19

List the functions of the nasal cavities

Answer 19

Conduit for air into nasopharynx
Filters air via vibrissae
Humidifies air
Warms inspired air
Sense of smell

Question 20

List the paranasal sinuses, and the drainage site for each

Answer 20

2 x frontal sinuses —> middle meatus
2 x maxillary sinuses —> middle meatus
2 x ethmoid air cells —> superior and middle meatuses
2 x sphenoid sinuses —> sphenoethmoidal recess

Question 21

The maxillary sinuses are also known as…

Answer 21

Antra

Question 22

What type of tissue lines the paranasal sinuses?

Answer 22

Mucous secreting respiratory mucosa

Question 23

What secretes mucous from the paranasal sinuses into the nasal cavities?

Answer 23

Ostia in lateral wall of cavities

Question 24

Outline the drainage pathway for lacrimal fluid

Answer 24

Lacrimal gland —> Tears —> Wash over eye —> Nasolacrimal duct —> Inferior meatus

Question 25

What is the only fluid that drains into the inferior meatus?

Answer 25

Lacrimal fluid

Question 26

What is sinusitis?

Answer 26

Inflammation of mucosa of paranasal sinuses

Question 27

What nerves cause pain to be felt in sinusitis?

Answer 27

CN V1 and V2

Question 28

The trigeminal nerve refers pain to…

Answer 28

Maxilla/ mandible
Antral mucosa
Teeth

Question 29

State the most common site for sinusitis. Why is this the most common?

Answer 29

Maxillary sinuses
They are predisposed to inflammation as ostia are located superior in the medial wall (not in the floor), therefore mucous drains against gravity

Question 30

List a common complication of teeth extraction. How is this managed?

Answer 30

Oroantral fistula
Roots of teeth spread infection of dental abscess to the antrum causing sinusitis
Surgery if persistant