Anatomy - Nasal Cavities and Paranasal Sinuses

Question 1

Which bones comprise the bony part of the nasal septum?

Answer 1

1. Perpendicular plate of the ethmoid bone
2. Vomer

(also small contributions from palatine bone and maxilla)

Question 2

Which conchae are associated with the ethmoid?

Answer 2

Superior and middle

(inferior is a separate bone)

Question 3

What contributes to the roof of the nasal cavities?

Answer 3

Cribriform plate and crista galli of the ethmoid

Question 4

The lateral walls of the nasal cavities are formed from what?

Answer 4

Superior and middle conchae

Question 5

Which Le Fort fractures may disrupt the ethmoid bone?

Answer 5

II and III

Question 6

What is the danger of disrupting the ethmoid bone in a Le Fort fracture?

Answer 6

Infection can spread from nasal and paranasal sinuses into anterior cranial fossa

Question 7

Which types of epithelium can be found in the nasal cavities?

Answer 7

1. Keratinised stratified squamous epithelium (at nostrils)
2. Respiratory epithelium
3. Olfactory mucosa

Question 8

What are the two key properties of respiratory epithelium?

Answer 8

1. Ciliated
2. Secreted mucous

Question 9

What are the two main functions of mucous production by the respiratory epithelium?

Answer 9

1. Traps pathogens
2. Warms/humidifies air

Question 10

Where do respiratory cells from the olfactor nerve pass into the nasal cavity?

Answer 10

Cribriform plate of the ethmoid

Question 11

Where do the olfactory tracts end?

Answer 11

Temporal lobe

Question 12

What provides the sensory supply to the nasal cavity?

Answer 12

Trigeminal nerve

• Opthalmic division (V1) - anterosuperior aspect
• Maxillary division (V2) - posteroinferior aspect

Question 13

Where does the blood supply for the nasal cavities originate?

Answer 13

External and internal carotid arteries

Question 14

Which arteries directly supply the face and nasal cavities?

Answer 14

1. Facial (from external carotid)
2. Maxillary (from external carotid)
3. Ophthalmic (from internal carotid)

Question 15

Which arteries does the ophthalmic artery contribute to the nasal cavity blood supply?

Answer 15

Anterior and posterior ethmoidal arteries

Question 16

Which arteries does the maxillary artery contribute to the nasal cavity blood supply?

Answer 16

Sphenopalatine and greater palatine arteries

Question 17

Which arteries does the facial artery contribute to the nasal cavity blood supply?

Answer 17

Lateral nasal branch of facial artery

or

Septal branch of superior labial artery

Question 18

What is the name given to the arterial anastomosis found on the nasal septum?

Answer 18

Kiesselbach’s (Little’s) area

Question 19

What makes Kiesselbach’s area a point to note?

Answer 19

It is a very common site of epistaxis

Question 20

What is the term given to the spaces below each of the conchae?

Answer 20

Meatuses

Question 21

How many meatuses can be found in the nasal cavity?

Answer 21

3

(superior, middle and inferior)

Question 22

What is the purpoe of the nasal conchae?

Answer 22

1. Create turbulent air flow for better gas exchange
2. Creates a larger surface area for respiratory epithelium to function

Question 23

What will drain into the meatuses?

Answer 23

Paranasal sinuses

Question 24

What are paranasal sinuses?

Answer 24

Air-filled spaces in bone

Question 25

Name all of the different paranasal sinuses

Answer 25

1. 2 x Ethmoid air cells 2. 2 x Frontal bone sinuses (separated by bony septum) 3. 2 x Maxillary sinuses 4. 2 x Spenoidal sinuses

Question 26

What does mucous drain from into the nasal cavities?

Answer 26

Ostia (in lateral walls of the nasal cavities)

Question 27

Where does the frontal sinus drain?

Answer 27

Middle meatus

Question 28

Where do the ethmoid air cells drain?

Answer 28

Superior and middle meatuses

Question 29

Where does the sphenoidal sinus drain?

Answer 29

Sphenoethmoidal recess

Question 30

Where does the maxillary sinus drain?

Answer 30

Middle meatus

Question 31

How does lacrimal fluid drain into the nasal cavity?

Answer 31

Nasolacrimal duct

Question 32

How does lacrimal fluid drain out of the nasal cavity?

Answer 32

Inferior meatus

Question 33

What is the name for the location of the openings for the frontal sinus, maxillary sinus, and anterior ethmoidal sinus?

Answer 33

Semilunar hiatus (crescent-shaped groove in lateral wall of nasal cavity)

Question 34

What is the name given to the swelling on the superior border of the semilunar hiatus?

Answer 34

Ethmoid bulla

Question 35

What is sinusitis?

Answer 35

Inflammation of the mucosa found in the paranasal sinuses

Question 36

Causes of sinusitis include which main reasons?

Answer 36

1. Infection 2. Allergy 3. Autoimmunity

Question 37

How can a viral URTI lead to sinusitis?

Answer 37

Induces swelling of mucosa and limiting diameter of ostia Sinuses can fill with infected mucous

Question 38

Where may pain be referred in sinusitis?

Answer 38

Teeth

Question 39

Which sinus is most predisposed to inflammation?

Answer 39

Maxillary

Question 40

Why is the maxillary sinus most predisposed to inflammation?

Answer 40

Ostia are located superiorly in the medial wall of sinus compared with the floor in other sinuses Drainage of mucous occurs **against gravity**

Question 41

What may extraction of a tooth cause in relation to the maxillary sinus?

Answer 41

Oro-antral fistula (hole between root hole of tooth and maxillary sinus)

Question 42

Why can maxillary sinusitis present as toothache?

Answer 42

Common sensory innervation (CN V) 1. Maxilla/mandible 2. Antral mucosa 3. All teeth