nasal cavities and paranasal sinuses

Question 1

name 5 functions of the nasal cavities

Answer 1

acts as a patent conduit for air to be transported to the nasopharynx
filters air of particulate
humidifies air (glands)
warms air in the nasal passage (blood)
sense of smell as air passes over the olfactory epithelium

Question 2

what filters air of particulate material?

Answer 2

vibrissae (small hairs)

Question 3

what are the external components of the nose?

Answer 3

root
dorsum
tip 
ala
nostril/nares
septum
philtrum (of upper lip)

Question 4

the external nose is made of bone, true or false?

Answer 4

false
mixture of bone and cartilage
cartilage allows movement and change in shape of the nose

Question 5

what bones form the nose?

Answer 5

nasal processes of frontal and maxilla bone
nasal bone
ethmoid bone
- perpendicular plate of ethmoid bone
vomer
inferior nasal concha

Question 6

what bones form the septum?

Answer 6

perpendicular plate of ethmoid

vomer

Question 7

what are the components of the ethmoid bone?

Answer 7

perpendicular plate
cribiform plate = horizontal plate on top of perpendicular plate
crista galli = vertical plate sitting above cribiform plate
ethmoidal air cells

Question 8

which conchae does the ethmoid bone form?

Answer 8

superior and middle conchae

Question 9

which parts of the nose does the ethmoid form?

Answer 9

parts of the roof, lateral walls and septum of nasal cavity

Question 10

how is the inferior concha different to the middle and superior?

Answer 10

inferior is its own bone

while middle and superior are part of the ethmoid

Question 11

where do the conchae originate and extend into?

Answer 11

originate laterally and project medially towards the perpendicular plate of ethmoid (septum)

Question 12

which types of le fort fractures can affect the cribiform plate of ethmoid?

Answer 12

le fort 2 and 3

Question 13

what problem can result from disruption of cribiform plate?

Answer 13

anosmia (loss of smell)

Question 14

name another potential problem with le fort fracture

Answer 14

disruption of paranasal sinuses which can facilitate spread of infection

Question 15

what are the 2 areas of nasal mucosa?

Answer 15

nasal vestibule

nasal cavity

Question 16

what type of epithelium lines the nasal vestibule?

Answer 16

stratified squamous epithelium (keratinised to non-keratinised)

Question 17

what type of epithelium lines the nasal cavity?

Answer 17

respiratory epithelium
olfactory epithelium (sits superiorly)

Question 18

what is respiratory epithelium?

Answer 18

ciliated pseudostratified columnar epithelium with goblet cells

Question 19

what nerve is involved in olfaction?

Answer 19

olfactory nerve (CN 1)
special sensory

Question 20

describe the 5 steps in the olfactory pathway

Answer 20

1. receptor cells in the olfactory epitheliu
2. pass up through the cribiform plate
3. synapse with olfactory bulb (ganglion)
4. then neurons pass along olfactory tract
5. to temporal lobe and olfactory areas

Question 21

describe olfactory epithelium

Answer 21

ciliated pseudostratified columnar

with villi?

Question 22

describe somatic sensory innervation of the nasal cavity

Answer 22

upper portion = CN V1 (anterior ethmoidal nerve)

lower portion = CN V2 (nasopalatine nerve)

Question 23

how does the nasopalatine nerve enter the nasal cavity?

Answer 23

via sphenopalatine foramen
branches into 2 in each cavity
1 branch supplies lateral wall
1 branch supplies septum

Question 24

describe blood supply to the nose

Answer 24

originates from internal and external carotid
- facial artery
- maxillary artery
- ophthalmic artery
branches of all of the above

Question 25

what is kiessalbach's area?

Answer 25

AKA little's area site where anastomosis occurs between the arterial contributions located anterioinferiorly on nasal septum site of nosebleeds from trauma to nose etc

Question 26

what arteries contribute to the kiesselbach's area

Answer 26

``` anterior ethmoidal posterior ethmoidal sphenopalatine artery greater palatine artery lateral nasal artery septal branch of superior labial artery all branches of - facial artery - ophthalmic artery - maxillary artery ```

Question 27

what spaces exist above and below the nasal concha?

Answer 27

above superior concha = sphenoethmoidal recess below superior concha = superior meatus below middle meatus = middle meatus below inferior concha = inferior meatus

Question 28

where is an NG tube inserted?

Answer 28

below inferior concha

Question 29

describe what happens in the nasal cycle

Answer 29

airflow through the nose can be impacted by engorgement of the nasal mucosa one side will be engorged then change to the other side every 1-5 hours due to erectile tissue (arteriovenous)

Question 30

what are paranasal sinuses and name the 4 bilateral pairs?

Answer 30

``` open spaces within the skull frontal sinuses ethmoidal air cells maxillary sinuses (sometimes referred to as the antrum) sphenoid sinuses ```

Question 31

what lines the paranasal sinuses?

Answer 31

thin respiratory epithelium

Question 32

where is the sphenoid sinus in relation to the nasal cavity?

Answer 32

at upper aspect of posterior wall

Question 33

where does the sphenoid sinus drain?

Answer 33

sphenoethmoidal recess

Question 34

where does the posterior ethmoidal air cells drain?

Answer 34

superior meatus

Question 35

what sinuses drain into the semilunar hiatus of the middle meatus?

Answer 35

frontal sinus maxillary sinus anterior ethmoidal air cells

Question 36

what drains into the ethmoidal bulla of the middle meatus?

Answer 36

middle ethmoidal air cells

Question 37

what drains into the inferior meatus?

Answer 37

nasolacrimal duct

Question 38

describe the route of drainage of lacrimal fluid

Answer 38

drains inferomedially to the nasolacrimal duct which drains into the inferior meatus

Question 39

what is sinusitis and how does this occur?

Answer 39

inflammation of the mucosa in 1 or more of the paranasal sinuses cilia of resp mucosa waft mucous towards ostia viral URTI can cause swelling of mucosa, reducing diameter of ostia sinuses can become filled with infectious mucous and pressure builds

Question 40

name a potential complication of sinusitis

Answer 40

build up of fluid in the sinuses can cause increased pressure increased pressure in ethmoid and break the medial wall of the orbit and impact the eye/spread the infection to the optic nerve

Question 41

why is the maxillary sinus particularly predisposed to infection?

Answer 41

ostium of maxillary sinus is located superiorly in relation to its cavity cilia must work against gravity

Question 42

how can tooth extraction cause sinusitis?

Answer 42

oro-antral fistula can form between tooth socket and maxillary sinus allowing tooth infection to track up into the sinus if the roots pierce upwards into the maxillary sinus or if improper closure of oro-antral fistula