Anatomy and Physiology of Nose

Question 1

What is the nasal function?

Answer 1

–To function as an airway in respiration

–Particularly important in neonates who are obligate nasal breathers

Warms inspired air

Humidification

Filtration of large particulate matter by coarse hairs in the nasal vestibule

Mucus production trapping and ciliary clearance of particulate matter

Immune protection

Olfaction

Drainage/aeration of the middle ear via Eustachian tube

Drainage of paranasal sinuses and nasolacrimal duct

Voice modification

Pheromone detection via the vomero-nasal organ of Jacobsen

–Function debated in humans

Question 2

What type of mucosa is sinonasal mucosa?

Answer 2

•Respiratory ciliated columnar epithelium with goblet cells

Question 3

What is the function of sinuses?

Answer 3

• Help with vocal resonance
• Decrease the weight of skull and facial bones
• Act as buffer for trauma

Question 4

Here are the landmarks of the external nose

Answer 4

Question 5

More landmarks of external nose

Answer 5

Question 6

What is the external nose composed of?

Answer 6

• 1/3rd bony, 2/3rd cartilage
• Frontal processes of maxilla and nasal part of frontal bones

Question 7

What forms the midline partition of the internal nose?

Answer 7

Nasal septum

Question 8

What forms the lateral walls of the internal nose?

Answer 8

Turbinates

Question 9

What forms the roof of the internal nose?

Answer 9

Cribiform plate

Question 10

What forms the floor of the nose?

Answer 10

Hard palate

Question 11

What are the main components of the nasal septum?

Answer 11

Septal cartilage

Perpendicular plate of ethmoid

Vomer

Question 12

What is the clinical relevance of the septum?

Answer 12

•Deviation

–Again congenital or acquired. Acquired being almost always caused by trauma

• Septal perforation
• Septal haematoma

Question 13

Here are the turbinates

Answer 13

Question 14

What are turbinates?

Answer 14

•Bony scroll-like projections from lateral wall of nose

Question 15

What is each turbinate associated with?

Answer 15

•Each turbinate associated with its respective meatus

Question 16

What is the clinical relevance of turbinates?

Answer 16

•Clinical relevance – usually inferior turbinate only

–Can cause nasal blockage due to

• Infection
• Inflammation e.g allergic rhinitis

–Usually managed medically with topical steroid sprays

–Can be managed surgically with turbinate reduction surgery

Question 17

What are the paranasal sinuses?

Answer 17

• Frontal
• Maxillary x 2
• Ethmoid

–Anterior and posterior

•Sphenoid

Question 18

What drains through the inferior meatus?

Answer 18

Nasolacrimal duct

Question 19

What drains through the middle meatus?

Answer 19

–Frontal

–Maxillary

–Anterior ethmoid

Question 20

What drains through the superior meatus?

Answer 20

–Posterior ethmoid

–Sphenoid

Question 21

What is rhinosinusitis?

Answer 21

Inflammatory and infective process that affects the nasal passageway and contiguous paranasal sinuses

Question 22

What are the forms of rhinosinusitis?

Answer 22

–Acute (bacterial)

–Chronic

• Allergic
• Non allergic
• –With polyps
• –Without polyps

Question 23

What is the frontal and ethmoid sinus related to?

Answer 23

Anterior cranial fossa

Question 24

What is the maxillary sinus related to?

Answer 24

Orbits

Question 25

What is the sphenoid related to?

Answer 25

Optic nerve

Internal carotid artery

Cavernous sinus

Question 26

What can result from spread of infection trhough a sinus?

Answer 26

Meningitis

Intracranial abscess

Orbital sepsis

Question 27

What are risks of surgery on sinuses?

Answer 27

CSF leak

Orbital complications - worst case scenario - blindness

Question 28

What is the blood supply of the nasopharynx?

Answer 28

•Anterior

–Derived from branches of internal carotid artery

•Ophthalmic > Anterior/posterior ethmoid arteries

•Posterior

–Derived from branches of external carotid artery

•Sphenopalantine

Question 29

What is littles area?

Answer 29

A region in the anteroinferior part of the nasal septum where four arteries anastomose to form a vascular plexus.

Question 30

Which arteries form littles area?

Answer 30

Anterior ethmoidal (branch of ophthalmic)

Sphenopalatine artery (branch of maxillary)

Greater palatine artery (branch of maxillary)

Septal branch of the superior labial artery (branch of facial artery)

Question 31

Where does epistaxis normally occur?

Answer 31

Little’s area

Question 32

What are common causes of epistaxis?

Answer 32

• Trauma aka nose picking
• Anticoagulants
• Iatrogenic – surgery
• Idiopathic
• Hypertension

Question 33

What are the causes of olfactory dysfunction?

Answer 33

–Rhinosinusitis

–Post viral anosmia

–Trauma