Anatomy/Physiology - Nose & Sinus

Question 1

Functions of the nasal cavity?

Answer 1

• Warm and humidify inhaled air
• Immune barrier
• Smell
• Drainage and aeration of middle ear
• Drainage of paranasal sinuses and lacrimal duct

Question 2

What is choanal atresia?

Answer 2

Congenital disorder where the back of the nasal passage (choana) is blocked

Problem as neonates are obligate nasal breathers

Question 3

Describe the epithelium of the specialized nasal mucosal lining

Answer 3

• First 1/3 stratified squamous epithelium with nasal hairs

- Posterior 2/3 pseudo-stratified columnar epithelium with cilia & goblet cells

Question 4

Function of the mucus produced by goblet cells in the nasal cavity?

Answer 4

• Trap pathogens

Question 5

Which nerve is responsible for smell? Which bone does it travel through?

Answer 5

Olfactory nerve

Passes through the cribriform plate of the ethmoid bone

Question 6

Functions of the Sinuses?

Answer 6

• Reservoir of warm, humid air
• Lighten skull
• Crumple zones (protection)
• vocal resonance
• Immune barrier

Question 7

How much of the external nose is bony and how much is cartilaginous?

Answer 7

• 1/3 bony

- 2/3 cartilaginous

Question 8

Name the sections of the external nasal area

Answer 8

• Columella
• Tip
• Supratip
• Dorsum
• Nasion
• Glabella

Question 9

What forms the roof, walls and floor of the nasal cavity?

Answer 9

Roof - Cribriform plate (skull base)

Walls - Turbinates

Floor - Hard palate

Question 10

What structures make up the nasal septum?

Answer 10

• Septal cartilage
• Vomer bone
• Perpendicular plate of ethmoid bone

Question 11

Describe the quality of blood flow to the septal cartilage

Answer 11

Poor blood supply

Gets blood from mucosa overlying it

Question 12

What is a septal haematoma?

Answer 12

Localized bleeding outside of vessels in the septal mucosa - creates barrier of stagnant blood between septal cartilage and mucosal blood supply

Usually associated with trauma

Question 13

Possible consequences of septal haematoma?

Answer 13

• No new blood supply to cartilage
• Can lead to septal necrosis and perforation

Haematoma needs to be drained ASAP

Question 14

What are the three turbinates called? What is a turbinate?

Function?

Answer 14

Superior, Middle, Inferior

Bony projections from the lateral wall of the nose

Increase the SA of the nose (humidification and warming)

Question 15

What is located underneath the turbinates?

Answer 15

The corresponding meatus

Question 16

What is the nasolacrimal duct?

Answer 16

• Drainage pathway for lacrimal secretions (tears)
• From lacrimal sac (next to eye) to inferior meatus of nasal cavity

(runny nose when crying)

Question 17

What are the paranasal sinuses?

Answer 17

Air filled extensions of the respiratory part of the nasal cavity
Lined with respiratory epithelium, and all open back into the nasal cavity

Question 18

Four pairs of paranasal sinuses?

Answer 18

• Frontal
• Maxillary
• Ethmoid air cells
• Sphenoid

(not sure if the sphenoid is paired?)

Question 19

Where is the frontal sinus? Where does it drain to?

Pathway of drainage?

Answer 19

Frontal sinuses are behind eyebrows

Drain to the middle meatus

Drains via frontal recess, moves inferiorly, just lateral to middle turbinate

Question 20

Where are the ethmoid air cells?

Two divisions of the ethmoid sinuses?

Answer 20

Honeycomb structure between the eyes

Anterior and posterior

Question 21

What separates the anterior and posterior ethmoid sinuses?

Answer 21

The ground lamella

- the turn of the middle turbinate at the back of the nose, where it attaches to the lateral nasal wall

Question 22

Where does the anterior ethmoid sinus drain to?

The posterior sinus?

Answer 22

Anterior - middle meatus

Posterior - superior meatus

Question 23

If sinusitis spreads to the ethmoid air cells, how may the disease progress?

Answer 23

Infection may spread to the orbits because bone of the ethmoid sinuses separating it from the orbit is paper thin

Causes periorbital/orbital cellulitis - won’t improve until sinusitis is treated

Question 24

Where does the sphenoid sinus drain to?

What neurovasculature is closely associated with the sphenoid sinus?

Answer 24

Drains into sphenoethmoidal recess (above superior turbinate)

Optic nerve runs above, internal carotids either side

Question 25

What can severe sinusitis in the sphenoid sinus lead to?

Answer 25

Neurological complications

Question 26

Where are the maxillary sinuses? Where do they drain to?

What happens when they get infected?

Answer 26

Behind each cheek
Drains into middle meatus

Facial pain when infected

Question 27

What is sinusitis? Usual progression of the condition?

Answer 27

Inflammation of the sinonasal mucosa - allergies/infection

Normally self limiting - < 12 weeks

Question 28

How can chronic sinusitis progress?

Answer 28

• Inflammation can block sinus drainage
• Mucus in sinus gets infected, more inflammation
• Persistent inflammation can lead to polyps

Question 29

Treatment options for sinusitis?

Answer 29

• Remove allergens or treat infection
• Steroids to reduce inflammation
• Surgery to remove polyps or unblock sinus pathways

Question 30

Which arteries supply the nasal cavity?

Answer 30

From ECA:

• Sphenopalatine A. (maxillary)
• Greater palatine (via maxillary)
• Superior labial (via facial)

From ICA:
- Anterior and Posterior Ethmoidal A. (via ophthalmic)

Question 31

What nerve innervates the nasal cavity?

Answer 31

Almost all trigeminal (V1 Opthalmic, V2 Maxillary)

• Vidian nerve provides some parasympathetic innervation

Question 32

What structures are located in the post nasal space?

Answer 32

• Eustachian tube

- Fossa of Rosenmuller (nasopharyngeal carcinomas frequently arise here)

Question 33

What mechanism of the soft palate helps equalize the middle ear?

Answer 33

The soft palate attaches to the eustachian tube during swallowing to open it

Question 34

What post nasal structure is present in children but not adults? Function?

Answer 34

Adenoids

Lymphatic masses, help immunity