Nose & Sinus - Anatomy and Physiology

Question 1

What is the primary nasal function?

Answer 1

To function as an airway in respiration.

Question 2

Describe the sinonasal mucosa.

Answer 2

Respiratory ciliated columnar epithelium with goblet cells.

Question 3

Why is nasal function so important in neonates?

Answer 3

Neonates are obligate nasal breathers.

Question 4

What changes does the nasal passage carry out to the air coming in?

Answer 4

• Warms the air
• Humidification

Question 5

What are some of the basic protective functions of the nasal passage?

Answer 5

• Filtration of large particulate matter by coarse hairs (vibrisae) in the nasal vestibule.
• Mucus production, trapping and ciliary clearance of particulate matter.
• Immune protection

Question 6

Smell is one of the other important functions of the nose. What is the medical terms?

Answer 6

Olfaction.

Question 7

The nasal passage is also responsible for the drainage of what?

Answer 7

• Drainage/aeration of the middle ear via Eustachian tube
• Drainage of paranasal sinuses and nasolacrimal duct

Question 8

What are the function of the sinuses?

Answer 8

Debated, but some thoughts are..

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

Question 9

How much of the external nose is bone vs cartilage?

Answer 9

• 1/3rd bony, 2/3rd cartilage

Question 10

What are the structures which make up the external nose?

Answer 10

.

Question 11

What is the name of the midline partition in the internal nose?

Answer 11

Nasal septum.

Question 12

What form the lateral walls of the internal nose?

Answer 12

Turbinates

Question 13

What froms the “roof” of the internal nose?

Answer 13

Cribiform plate

Question 14

What is the name of the “floor” of the internal nose?

Answer 14

Hard palate

Question 15

What are the associated structures of the internal nose?

Answer 15

Paranasal sinuses

Nasopharynx

Question 16

What are the structures which make up the nasal septum?

Answer 16

• Perpendicular plate of ethmoid bone.
• Vomer bone
• Septal Cartilage

(mainly)

Question 17

What is the clinical relevance of the septum?

Answer 17

Deviation may occur. (this can be congenital or aquired)

Septal perforation and haematoma may occur.

Question 18

What are turbinates?

Answer 18

• Bony scroll-like projections from lateral wall of nose.

Question 19

How many and what are the names of the turbinates? (also known as conchae)

Answer 19

3

• Superior
• Middle
• Inferior

Question 20

What are the names of the air pathyways created by these bony projections?

Answer 20

These pathways are called meatuses.

Question 21

What is the clnincal relevance of the turbinates?

Answer 21

• Usually the only clinical relevance is the inferior turbinate.
• This can cause blockages due to inflammation or infection.
• Usually this can be managed through the use of topical steroid sprays.
• If the issue requires so there can be surgical management with turbinate reduction surgery.

Question 22

What are the paranasal sinuses?

Answer 22

Air cavities in the bones of the face.

Question 23

What are the names of the paranasal sinuses?

Answer 23

• Frontal
• Maxillary (x2)
• Ethmoid (anterior and posterior)
• Sphenoid

Question 24

What is the function of the Nasolacrimal duct and where does it drain?

Answer 24

The nasolacrimal duct acts to drain tears from the eye – it opens into the inferior meatus.

Question 25

Which sinuses drain into the middle meatus?

Answer 25

The frontal, maxillary and anterior ethmoidal sinuses open into the middle meatus.

Question 26

What sinuses drain into the superior meatus?

Answer 26

The posterior ethmoid and sphenoid sinuses drain into the superior meatus.

Question 27

What is the clinical relevance of knowing the associations between a sinus and where it drains?

Answer 27

Relevant in Rhinosinusitis, which reflects a concurrent inflammatory an dinfective process that affects the nasal passageway and contiguous para nasal sinuses.

Question 28

What are the 2 subtypes of rhinosinusitis?

Answer 28

* Acute (bacteial) (less than 12 weeks) * Chronic (more than 12 weeks) - Allergic and Non Allergic, there may also be polyp formation.

Question 29

What is the importnat anatomical relation for the frontal and ethmoid sinuses?

Answer 29

Anterior cranial fossa

Question 30

What are the important anatomical relations of the maxillary sinus?

Answer 30

Orbits

Question 31

What are the important anatomical relations of the sphenoid sinus?

Answer 31

Optic nerve Internal carotid artery Cavernous sinus

Question 32

Why is it important to understand the the anatomical relations of the various sinuses in the head?

Answer 32

Spread of infections * Meningitis * Intracranial abscess * Orbital sepsis Risks of Surgery * CSF leak * Oribital complications (worst case scenario - blindness)

Question 33

How is the blood supply of the nasal passage roughly divided?

Answer 33

Broadly divided into an anterior and posterior supply

Question 34

Outline the anterior blood supply in the nasal passage.

Answer 34

Derived from branches of internal carotid artery * Ophthalmic \> Anterior/posterior ethmoid arteries

Question 35

Outline the posterior blood supply in the nasal passage.

Answer 35

Derived from branches of external carotid artery * Sphenopalantine

Question 36

What is Little's Area?

Answer 36

Area in the anterior nose where there are lots of anastomoses between the supplying arteries.

Question 37

What is Epistaxis? What are the common causes?

Answer 37

Nose bleed (occurs mostly from Little's Area) * Trauma aka nose picking * Anticoagulants * Iatrogenic – surgery * Idiopathic * Hypertension

Question 38

What is the venous drainage of the nose?

Answer 38

The veins of the nose tend to follow the arteries. They drain into the pterygoid plexus, facial vein or cavernous sinus.

Question 39

Outline the innervation of the nose in terms of the "special innervation".

Answer 39

* Special sensory innervation refers to the ability of the nose to smell. * This is carried out by the olfactory nerves. The olfactory bulb, part of the brain, lies on the superior surface of the cribriform plate, above the nasal cavity. * Branches of the olfactory nerve run through the cribriform plate to provide special sensory innervation to the nose.

Question 40

Oultine the nerves involved in the general innervation of the nasal cavity.

Answer 40

* General sensory innervation to the septum and lateral walls is delivered by the nasopalatine nerve (branch of maxillary nerve) and the nasociliary nerve (branch of the ophthalmic nerve). * Innervation to the external skin of the nose is supplied by the trigeminal nerve.