8. paranasal sinuses (lecture)

Question 1

what are paranasal sinuses?

Answer 1

air filled spaces that are extensions of nasal cavity

Question 2

what are paranasal sinuses lined with?

Answer 2

respiratory mucosa (also ciliated and secrete mucus)
pseudostratified ciliated columnar epithelium with goblet cells

Question 3

function of paranasal sinuses?

Answer 3

humidify and warm inspired air

reduce weight of skull

Question 4

where do all paranasal sinuses drain into?

Answer 4

nasal cavity via small channels (ostia) - most into middle meatus

Question 5

what can infections in the nasal cavity involve?

Answer 5

sinuses (sinusitis)

maxillary sinus most commonly affected

Question 6

what are the 4 pairs of paranasal sinuses?

Answer 6

frontal
ethmoidal
sphenoidal
maxillary

Question 7

how are paranasal sinuses named?

Answer 7

according to which bone they are found in

Question 8

what do important anatomical relations of the paranasal sinuses include?

Answer 8

the orbit
anterior cranial fossa (ethmoidal air cells and frontal sinus)
roots of upper teeth can sometimes project in maxillary sinus

Question 9

what is acute sinusitis?

Answer 9

acute inflammation of lining of sinus lasting (<4 weeks)

Question 10

what are common causes of acute sinusitis?

Answer 10

commonly infective,

often secondary to viral infection of nasal cavity (common cold)

Question 11

what is diagnosis of acute sinusitis based on?

Answer 11

history and examination:

1. non-resolving cold / flu-like illness
2. pyrexia
3. rhinorrhoea +/- green / yellow discharge
4. headache / facial pain (in area of affected sinus)
5. blocked nose

Question 12

when is headache / facial pain worse in acute sinusitis?

Answer 12

on leaning forward

Question 13

what are ostia?

Answer 13

small channels in which paranasal sinuses drain in nasal cavity (commonly middle meatus)

Question 14

what are conditions which may block ostia of sinuses?

Answer 14

e.g. nasal polyps

Question 15

what increases the risk of sinusitis?

Answer 15

deviated septum

Question 16

what is another cause of sinusitis?

Answer 16

dental infection (involving upper teeth)

Question 17

how is acute sinusitis usually treated?

Answer 17

normally self-limiting

usually 1 week, sometimes 2-3 weeks

Question 18

what can primary (viral) infection e.g. rhinitis lead to?

Answer 18

reduced ciliary function,
oedema of nasal mucosa and sinus ostia,
therefore: increased nasal secretions

Question 19

what is impeded in acute sinusitis?

Answer 19

drainage from sinus

Question 20

what can stagnant secretions within the sinus in acute sinusitis lead to?

Answer 20

ideal breading ground for bacteria-secondary infection

commonly strep / haemophilus

Question 21

what are symptomatic treatments of acute sinusitis?

Answer 21

nasal decongestants (from increased secretions)
pain killers may be helpful

Question 22

what is done in severe / prolonged episodes of acute sinusitis?

Answer 22

antibiotics may be given

Question 23

what is the nerve innervation of nasal cavity and paranasal sinuses to the antero-superior portion? including what?

Answer 23

including most of PARANASAL sinuses:
ophthalmic nerve (CN V1/a)
branches of ophthalmic artery (anterior + posterior ethmoid)

Question 24

what is the nerve innervation of the nasal cavity and paranasal sinuses to posterio-inferior portion? including what?

Answer 24

including MAXILLARY sinus:
maxillary nerve (CN V2/b)
branches of maxillary artery (sphenopalatine artery)

Question 25

what is sphenopalatine artery’s origin?

Answer 25

external carotid > maxillary > sphenopalatine

Question 26

what are anterior and posterior ethmoidal arteries’ origin?

Answer 26

inferior carotid > ophthalmic artery > anterior and posterior ethmoidal arteries

Question 27

management of epistaxis?

Answer 27

initial: pinching Kisselbach’s area
later: merocel nasal tampon