week 1 anatomy Nosebleeds/sinuses

Question 1

what are the nares?

Answer 1

nostrils

Question 2

what is the septum made up from?

Answer 2

vomer and perpendicular plate of ethmoid bone

Question 3

what makes up the roof of the ethmoid bone?

Answer 3

cribriform plate and crista galli (+anterior cranial fossa)

Question 4

what makes up the lateral wall of the ethmoid bone?

Answer 4

superior and middle conchae, ethmoidal air cells, orbital plate of ethmoid (+inferior conchae)

Question 5

what part of the ethmoid bone makes up the septum

Answer 5

perpendicular plate

Question 6

where do the olfactory nerves pass through (like a sieve?)

Answer 6

cribriform plate

Question 7

what occurs in the olfactory club and what happens to the nerves afterward?

Answer 7

synapse in bulb, travel through olfactory tract and into temporal lobe

Question 8

what kind of # can disrupt the cribriform plate of the ethmoid bone? why is this bad?

Answer 8

Le Fort II & III level fractures

danger of infection spreading from the nasal cavity & paranasal sinuses into the anterior
cranial fossa

Question 9

what type of cartilage is the septum made from?

Answer 9

hyaline

Question 10

what mucosa is found in the nasal cavity?

Answer 10

nares=keratinised stratified squamous epithelium

respiratory epithelium =majority

olfactory mucosa = near olfactory nerves

Question 11

what is CN1?

Answer 11

olfactory nerve

Question 12

what are the concha made of?

Answer 12

sup and middle = part of ethmoid

inf=bone on its own

Question 13

what is the somatic sensory nerve supply to the nasal cavitys??

Answer 13

CNv1 = anterosuperiorly

CN V2 =posteroinferiorly

Question 14

describe the blood supply to the nasal cavities?

Answer 14

external carotid →facial→lateral nasal and septal branch of superior labial artery

external carotid→ maxillary→sphenopalatine and greater palatine arteries

internal carotid→ophthalmic artery→ anterior and posterior ethmoidal arteries

Question 15

what is Kiesselbach’s (Little’s) area?

Answer 15

an arterial anastomosis on the nasal septum

a common site of epistaxis (nosebleeds)

Question 16

what arteries AE, PE, SP, GP at little’s/Kiesselbach’s

Answer 16

Anterior ethmoidal artery (branch of the ophthalmic artery)
Sphenopalatine artery (terminal branch of the maxillary artery)
Greater palatine artery (from the maxillary artery)
Septal branch of the superior labial artery (from the facial artery)

Posterior ethmoidal artery debatable

Question 17

what are the concha? what are the meatuses?

Answer 17

turbinate bone (sup, middle, inf)

‘spaces’ under each concha (sphenoethmoidal (recess), superior meatus, middle meatus, inferior meatus )

Question 18

NG tube what nerve can be involved in insertion? how to confirm?

Answer 18

V2, Little’s area on the septum giving epistaxis.

Xray to confirm

Question 19

function of nasal cavities

Answer 19

air passage, filters (vibrissae=small hairs), humidifies, warms, sense of smell

Question 20

what paranasal sinuses are there?

Answer 20

1 frontal bone
x2 frontal sinuses
separated by bony septum

2 maxillae
x2 maxillary sinuses (antra)

1 ethmoid bone
x2 sets ethmoidal air cells

1 sphenoid bone
x2 sphenoidal sinuses

Question 21

what are the paranasal sinuses lined by?

Answer 21

mucous-secreting respiratory mucosa

Question 22

how does the mucus drain from paranasal sinuses?

Answer 22

via ostia in the lateral walls of the nasal cavities

Question 23

where do the ethmoid sinuses drain?

Answer 23

sup and middle meatuses

Question 24

where do the sphenoid sinuses drain into?

Answer 24

sphenoethmoidal recess

Question 25

where do the maxillae sinuses (antra) drain into?

Answer 25

middle meatus

note drain up to empty, meaning inc risk of infection

Question 26

where do the frontal sinuses drain into?

Answer 26

middle meatus

Question 27

what drains into the inf meatus?

Answer 27

nasal lacrimal duct (tears) = runny nose when crying

Question 28

what is sinusitis? how can it present? what is it due to?

Answer 28

inflammation of the mucosa of paranasal sinuses

acute/sub chronic / chronic

causes include infection, allergy, autoimmune issues

Question 29

mechanism of sinusitis

Answer 29

smoking/cold cases cilia to stop working and mucus is not moved

Viral URTIURTI can cause swelling of mucosa, reducing diameter of ostia - so can’t drain mucus

sinuses can become filled with infected mucous

Question 30

where is pain from sinusitis referred to? why?

Answer 30

painful – sensation provided by CN V1 and V2

pain may be referred to teeth

Question 31

which sinus is predisposed to inflammation? why?

Answer 31

maxillary sinus

due to maxillary sinus ostia being located superiorly in the medial wall of the sinus compared to the floor

maxillary sinus mucous has to drain against gravity

Question 32

what may extraction of tooth result in? treatment?

Answer 32

an oro-antral fistula

a persistent oro-antral fistula (incomplete healing) is surgically closed