Nasal cavity and paranasal air sinuses

Question 1

The nasal passages are connected to the nasopharynx by which structures?

Answer 1

Nasal choanae

Question 2

What pathology could affect the nasal choanae and in which age group is it most common?

Answer 2

Choanal atresia – a congenital blockage of the choanae, which can be unilateral or bilateral, leading to difficulty breathing, particularly in infants

Question 3

What are the nasal concha?

Answer 3

Bony shelves that project inferomedially from the lateral wall on both sides

Question 4

What is the space under each concha called?

Answer 4

Meatus

Question 5

How do the concha affect the temperature of air that is breathed in through the nasal cavity?

Answer 5

As air passes over the highly vascular mucosal tissue of the conchae, it is warmed to near body temperature

Question 6

What kind of air flow do the shape of the concha produce and why is this helpful?

Answer 6

Turbulent air flow, which helps slow down the movement of air for temperature regulation and filtration of particles so they do not reach the lungs

Question 7

How does the nasal cavity affect sound?

Answer 7

It produces resonance – the amplification of sound frequencies as they pass through the nasal passages

Question 8

What are the 3 regions that the nasal cavity can be divided into based on the mucosa that lines it?

Answer 8

Nasal vestibule region

Olfactory region

Respiratory region

Question 9

What epithelium lines the respiratory region of the nasal cavity?

Answer 9

Pseudostratified ciliated columnar epithelium

Question 10

What are the components of the nasal septum?

Answer 10

Septal cartilage

Ethmoid bone

Vomer

Question 11

The superior and middle concha are part of which bone?

Answer 11

Ethmoid bone

Question 12

Which bones comprise the lateral wall of the nasal cavity?

Answer 12

Superior and middle concha (ethmoid bone)

Inferior concha

Palatine

Maxilla

Question 13

Describe the blood supply to the nasal cavity.

Answer 13

The anterior and posterior ethmoidal arteries branch off from the internal carotid artery

The sphenopalatine artery branches off from the maxillary artery, which is a branch of the external carotid artery

Question 14

In which area do the arteries from both the internal and external carotid systems anastomose and what is the name given to this area?

Answer 14

The anterior nasal septum – Kiesselbach’s Plexus (Little’s Area)

Question 15

Describe innervation of the nasal cavity.

Answer 15

Olfactory nerve and trigeminal nerve Va (ophthalmic division) & Vb (maxillary division)

Question 16

Considering referred pain, where could a pathology in the front of the nasal cavity refer pain to?

Answer 16

Forehead

Question 17

Considering referred pain, where could a pathology in the middle and back of the nasal cavity refer pain to?

Answer 17

Maxillary teeth

Question 18

The fibres of the olfactory nerve pass through what to enter the nasal cavity?

Answer 18

Cribriform plate

Question 19

What could a fracture of the cribriform plate lead to?

Answer 19

A cerebral spinal fluid leak

Question 20

Tears drain through the nasolacrimal duct to drain into where?

Answer 20

Inferior meatus

Question 21

What is dacryocystitis?

Answer 21

Inflammation and infection of the lacrimal sac

Question 22

What is dacrostenosis?

Answer 22

Obstruction of the nasolacrimal duct

Question 23

What are the 4 pairs of sinuses?

Answer 23

Frontal
Ethmoid
Maxillary
Sphenoid

Question 24

Describe the innervation of the sinuses.

Answer 24

All sinuses are innervated by CN Va except the maxillary sinus which is innervated by CN Vb

Question 25

Where do the sphenoid sinuses drain into?

Answer 25

Sphenoethmoidal recess

Question 26

Where do the frontal, maxillary, and majority of the ethmoid sinuses drain into?

Answer 26

Middle meatus

Question 27

The maxillary sinus drains into the middle meatus via what?

Answer 27

Semilunar hiatus

Question 28

The sphenoid sinus can be used in surgery to access what?

Answer 28

Pituitary gland

Question 29

What separates the ethmoid sinuses from the orbit?

Answer 29

Lamina papyracea

Question 30

Due to the thinness of the lamina papyracea, ethmoid sinus infections can lead to what pathology?

Answer 30

Periorbital cellulitis