The Nasal Cavity

Question 1

What are the regions of the nasal cavity?

Answer 1

Vestibule, olfactory region, respiratory region

Question 2

What are the nasal conchae and how many are there?

Answer 2

Curved shelves of bone which project out the lateral walls

Three -inferior -middle -superior

Question 3

What are the pathways that the nasal conchae create called and how many are there and there location?

Answer 3

Inferior meatus: between the inferior concha and the floor of the nasal cavity

Middle meatus: between the inferior and middle conchae

Superior meatus: between middle and superior conchae

Spheno-ethmoidal recess: lies superiorly and posteriorly to the superior concha

Question 4

Function of the nasal conchae?

Answer 4

Increase the surface area of the nasal cavity

Make airflow turbulent so it stays longer in the nasal cavity so it can be humidified

Question 5

Which paranasal sinuses open up into the middle meatus and what is the opening marked by?

Answer 5

Frontal

Maxillary

Anterior ethmoidal

Semilunar hiatus - a crescent shaped groove on the lateral walls of NC

Question 6

What do the middle ethmoidal sinuses drain into and what is it?

Answer 6

Ethmoidal bulla

A bulge in the lateral wall formed by the sinus

Question 7

Where does the posterior ethmoidal sinus drain into?

Answer 7

Level of the superior meatus

Question 8

Where does the sphenoid sinus drain into?

Answer 8

Posterior roof

Question 9

Where does the nasolacrimal duct drain into?

Answer 9

The inferior meatus

Question 10

Where does the Eustachian tube open into?

Answer 10

Nasopharynx at the level of the inferior meatus

Question 11

Which bone is the cribriform plate a part of and what is does it allow?

Answer 11

Ethmoid bone

Forms a portion of the nasal cavity

Contains small perforations allowing fibres of the olfactory nerve to enter and exit

Question 12

Where is the sphenopalatine foramen located and what does it allow?

Answer 12

At the level of the superior meatus

Allows communication between the nasal cavity and the pterygopalatine fossa

Sphenopalatine artery, nasopalatine nerve and superior nasal nerves pass through here

Question 13

What is the incisive canal?

Answer 13

A pathway between the nasal cavity and the incisive fossa of the oral cavity.

Transmits the nasopalatine nerve and the greater palatine artery

Question 14

Why is it useful that the nose has a very rich blood supply?

Answer 14

Effectively change humidity and temperature of inspired air

Question 15

Where does the nose receive blood from?

Answer 15

Internal carotid branches

• anterior ethmoidal artery
• posterior ethmoidal artery

These are branches of the ophthalmic artery, descend into the nasal cavity through the cribriform plate

External carotid branches -sphenopalatine artery -greater palatine artery -superior labial artery -lateral nasal arteries

Question 16

Where do the veins of the nose drain into?

Answer 16

Follow the arteries

Into the pterygoid plexus, facial vein or cavernous sinus

Question 17

In some individuals, a few nasal veins can join into which sinus and be a pathway for infection to spread into the cranial cavity?

Answer 17

The saggital sinus - a dural venous sinus

Question 18

How can infection of the auditory tube diminish hearing?

Answer 18

Get swelling of the mucous linings, blocking the tube

Question 19

Which nerves are for special sensory innervation of the nose?

Answer 19

Olfactory nerves from the olfactory bulb, which lies on the superior surface of the cribriform plate, above the nasal cavity

Question 20

Which nerves supply general sensory innervation to the nose?

Answer 20

Nasopalatine nerve (branch of maxillary) and nasociliary nerve (branch of ophthalmic) - septum and lateral walls

Trigeminal nerve - external skin

Question 21

How can a fracture of the cribriform plate occur?

Answer 21

As a result of nose trauma

Either fractured directly by the trauma or fragments of the ethmoid bone

Question 22

What can a fracture of the cribriform plate lead to?

Answer 22

The plate can penetrate the meningeal linings of the brain, causing leakage of cerebrospinal-spinal fluid Increases the risk of meningitis, encephalitis and brain abscesses because the brain is exposed to the outside environment

Olfactory bulb which lies on it can be irreversibly damaged leading to anosmia

Question 23

Where does the nasal cavity extend from and to?

Answer 23

Vestibule to nasopharynx

Question 24

Which bones make up the bony part of the nasal skeleton?

Answer 24

Nasal bones

Maxillae frontal processes

Frontal bone (nasal part and nasal spine)

Question 25

Name the cartilgaes that make up the cartilaginous part of the nose

Answer 25

2 lateral cartilages

2 alar

1 septal

Question 26

What are the parts of the nasal septum?

Answer 26

Anterior portion - cartilaginous

Middle portion - perpendicular plate of ethmoid bone

Posterior portion - vomer

Question 27

Which bones is the hard palate made up of?

Answer 27

Palatine and maxillary bones

Question 28

Complication of a fracture to the nasal cavity?

Answer 28

Septal haematoma

Question 29

Structure of the olfactory cells?

Answer 29

Axonal process of the cells pass through the cribriform plate and penetrate the meninges before entering the olfactory bulb

Question 30

Where is the area where nosebleeds usually occur? Why?

Answer 30

Kiesselbach’s area

Rich in capillaries where all the arteries supplying the septum anastamose

Question 31

Which artery is the cause of posterior bleeds?

Answer 31

Sphenopalatine artery

Question 32

Causes of rhinitis?

Answer 32

Viral

• Adenovirus
• Rhinovirus
• Respiratory syncytial virus

Allergic

Nasal polyps

Question 33

What can nasal polyps lead to?

Where are they normally found?

Answer 33

Snoring/obstructive sleep apnoea

Close to the ostiomeatal complex of the nasopharynx

Question 34

What are the different types of sinusitis?

Answer 34

Acute: 7-30 days

Sub-acute: 4-12 weeks

Chronic: >90 days

Question 35

Causes of sinusitis?

Answer 35

Viral with secondary infection

• Streptococcus pneumoniae
• Haemophillus influenzae

Question 36

What complications can an ethmoidal sinus air cell infection cause?

Answer 36

May break through the medial wall of the orbit

Close proximitiy to the optic canal which transmits the optic nerve and ophthalmic artery causing visual disorders

Question 37

Why can sinusitis be perceived as toothache?

Answer 37

Superior alveolar nerve branches of the maxillary nerve (V2) supply both the maxillary teeth and the mucous membrane of the maxillary sinuses