Anatomy/physiology of Nose and Sinus

Question 1

What is the function of the nasal airways? (2)

Answer 1

to warm and humidify inhaled air

immune barrier

Question 2

What is important about newborns and their breathing

Answer 2

Newborns breathe through their nose so if they are born with Cholan altresia this means they are born without the hole at the back of their nose so they can’t get air into their lungs

Question 3

What type of epithelium is in the first 1/3 and posterior 2/3 of the nose?

Answer 3

First 1/3 - stratified squamous epithelium + nasal hairs

Posterior 2/3 - pseudostratified columnar epithelium + cilia + goblet cells

Question 4

Nasal function (3)

Answer 4

smell
drainage of paranasal sinuses + lacrimal duct
drainage and aeration of middle ear - eustachian tube

Question 5

Describe how the nose smells

Answer 5

By the olfactory nerve - 1st cranial nerve
transmitted by the cribiform plate
receptors lie in the olfactory mucose
sense of smell can be lost if heavy nasal congestion

Question 6

Function of the sinuses (4)

Answer 6

reservoirs of warm, humid air - helps to lighten the skull (air pockets)

Crumple zones - if there is trauma to the head/face there is less impact to the brain

Vocal resonance - this is why your voice changes when you’re blocked up with a cold

Immune barrier - same mucosa

Question 7

What is the ratio of bone to cartilage in the external nose?

Answer 7

1/3 bone 2/3 cartilage

Question 8

What is the Glabella tap?

Answer 8

A test used in the diagnosis of parkinson’s. When you are tapped on the forehead there is a reflex usually that causes you to blink. This is lost in Parkinson’s patients.

Question 9

True or false: Cartilage is easily unbent

Answer 9

False - it is difficult to unbend cartilage and it actually requires surgery

Question 10

What makes up the roof, floor, walls and midline of the nose?

Answer 10

Floor - hard palate
Roof - Cribriform plate of ethmoid
Walls - turbinates
Midline - septum

Question 11

What are the 3 anatomical parts of the nasal septum?

Answer 11

septal cartilage (most anterior)
vomer
perpendicular plate of Ethmoid

Question 12

Where does the septum get its blood supply from

Answer 12

the mucosa overlying it - very poor blood supply

Question 13

Describe what a Septal haematoma is

Answer 13

often occurs post trauma
bleeding between cartilage and mucosal lining - it strips the perichondrium off the cartilage

Need to drain it to restore blood flow

Question 14

What are turbinates? what is their function?

Answer 14

projections from the lateral wall of the nose
there are superior, middle and inferior ones
They increase the surface area of the nose so increase humidifying and warming

they respond to temperature - increased blood suppply to nose if it is cold outside

Question 15

what open beneath turbinates?

Answer 15

sinuses and nasolacrimal duct

Question 16

What is a meatus?

Answer 16

the whole area underneath the turbinate

Question 17

What is the nasolacrimal duct?

Answer 17

drainage system of lacrimal secretions from the lacrimal sac (like some drainage of tears from the eyes)

Question 18

Which turbinate does the nasolacrimal duct open underneath?

Answer 18

inferior turbinate

Question 19

What are the paranasal sinuses?

Answer 19

2 frontal
2 maxillary
sphenoid - back of the nose, high up
ethmoid - between the eyes

Question 20

Where is the Frontal sinus and where does it drain to?

Answer 20

it lies behind the eyebrows
drains into the frontal recess via the middle meatus

drains under the middle turbinate

Question 21

Ethmoid sinus

Answer 21

ethmoid air cells - anterior and posterior ones

Question 22

where do the anterior ethmoid sinuses drain to

Answer 22

the middle turbinate

Question 23

where do the posterior ethmoid sinuses drain to

Answer 23

superior meatus lateral to the superior turbinate

Question 24

How is periorbital/orbital cellulitis caused?

Answer 24

infection that spreads through the paper thin bone between the orbit and ethmoids. The sinusitis infection needs treated with antibiotic otherwise the fluid in the orbit won’t get any better

Question 25

Sphenoid sinus

Answer 25

drains via the sphenoethmoidal recess
optic nerve runs above it and the ICA’s run either side
the pituitary gland lies behind it

Question 26

what neurological problems can sphenoid sinusitis lead to?

Answer 26

meningitis or dural abscess

Question 27

If a patient is experiencing facial pain, which type of sinusitis is it more likely to be?

Answer 27

maxillary

Question 28

Maxillary sinus

Answer 28

lie behind each cheek
drains via the middle meatus
facial pain=

Question 29

How does chronic sinusitis come about

Answer 29

ongoing infection - sinusitis is usually self-limiting but if it isn’t then it can become chronic
all sinuses drain through tiny tubes and these can become blocked with infection. Trapped mucus can become more infected which causes more inflammation

over time polyps can form

Question 30

Risks of surgery for polyps?

Answer 30

CSF leaks
orbital damage

surgery is not curative either - worth it?

Question 31

Treatment for polyps?

Answer 31

steroidal nasal spray - long term

Question 32

What is the blood supply to the nose?

Answer 32

internal - anterior + posterior ethmoidal artery

external - sphenopalatine artery

Question 33

What is Kiesselbach’s plexus?

Answer 33

most common site for nose bleeds
Important to pinch the soft tissue

it is just inside the nose and cracks easily due to inhaled air

Question 34

How is the nose innervated?

Answer 34

almost all by the trigeminal nerve
V1 - opthalmic
V2 - maxillary
Sensation internal and external by the vidian nerve - parasympathetic and the sympathetic innervation to the nasal mucosa

Question 35

what is the eustachian tube?

Answer 35

connects the middle ear to the nasopharynx and acts to equalise pressure

opens when swallowing

Question 36

Fossa of Rosenmuller

Answer 36

contains node of Rouvier

Nasopharyngeal cancer - this node would be the first place it would commonly spread to