L10.1 Nasal cavity and paranasal sinuses Flashcards
1
Q
Skeleton of the external nose
A
- Frontal process of maxilla
- Nasal bones = bridge of the nose
- Articulates SUP with bottom of frontal bone
- Septal cartilage → projects in mid sagittal plane → separate into 2 halves
- Alar cartilages on each side
- Inside of alar cartilage = vestibule
- Alar cartilages on each side
2
Q
Boundary of the MED nasal wall
A
- ANT by septal cartilage
- POS - vomer + body of sphenoid bone
- Floor - maxilla + palatine
- SUP - ethmoid bone (has projection in midline which closes the septum)
POS nare (one for each half of nasal cavity)
3
Q
Ethmoid bone
A
- (LAT plate, cribriform plate SUPeriorly)
- Looks like an ‘n’ shaped bone (3 plates)
- 1 midline + 2 LAT wall
- Broken nose → involves ethmoid bone
- Results in infections/bleeds/rhinorrhea (loss of CSF out of nasal cavity)
- Brain & meninges directly above ethmoid bone → bleeds from meninges
4
Q
CN 1 bulb
A
- CN 1 (olfactory N)’s bulb sits LAT to crista gali
- Projections through cribriform plates
- Takes information of smell to brain
5
Q
Mucous membrane
A
- Highly vascular and on MED wall
- Trap foreign particles
- Helps humidify air
- Mucosa is ciliated → help expel mucus in lower airways into front of nasal cavity to blow out
- Cilia is damaged from smoking
- Nosebleed associated with vasculature of mucosa
6
Q
Olfactory area
A
- Top 1/3 of nasal cavity (LAT & MED)
7
Q
Vestibule
A
- Lined by skin (keratinised → and ∴ protective) and hair
8
Q
Turbinates in the LAT wall
A
- Turbinates → contains conchae (SUP/MID/INF)
- Lined by mucosa
- Concha produce turbulence of air breathed in → warm and humid air breathed in
- Inflammation of concha → may congest nasal cavity
9
Q
Meatus
A
- found under concha (S/M/I)
- Meatus opens into paranasal sinuses
- Bacteria able to migrate into sinuses
- INF meatus has no opening into sinus
10
Q
Paranasal sinuses
A
- Spaces in bone (opens during development)
- Drags mucosa with it as it opens → lines spaces
-
Front/Ethomoid/Sphenoid/Maxillary
- Sinusitis → refer pain to trigeminal N
-
Maxillary sinus is close to roots of molars
- Pulling molars out → may fracture maxillary sinus → potential route of infection
11
Q
Sinus drainage
A
- Frontal/ethmoid/sphenoid → above nasal cavity
- Bac needs to work against gravity to get into sinus → drains effectively in upright position
- Maxillary sinus (opening in MED wall)
- Bac works with gravity to get into sinus → not able to drain effectively in upright position
- Need to lie in a slight decline position
12
Q
Opening of sinus drainage
A
- Tend to open in nasal cavity close to sinus
- Frontal → opens into MID meatus (close to hiatus semilunaris)
-
Sphenoid → opens at back end of nasal cavity (associated with SUP concha)
- In the area of sphenoethmoidal recess
-
Ethmoid → directly into SUP meatus
- Hiatus semilunaris → ANT ethmoid air cells
- Bulla ethmoidalis → Middle ethmoidal air cells
- Maxillary → POS end of hiatus semilunaris
13
Q
How is the INF meatus different
A
- Opens into nasolacrimal duct
- Excessive tear production → into nasolacrimal duct → into INF meatus → runny nose
14
Q
POS quadrant for BS to nasal cavity
A
- Spenopalatine A (big A)
15
Q
SUP quadrant for BS to nasal cavity
A
- Branches of the opthalmic A
- → Ethmoidal A
16
Q
INF quadrant
A
- Branches of the Greater palatine A
- Supplies roof of mouth from underneath → comes up through opening in hard palate → supply INF quadrant
17
Q
ANT quadrant for BS to nasal cavity
A
- LAT → branches from facial A
- MED → branches from lip (labial A)
19
Q
NS to the nasal cavity
A
- Line from ANT nare to sphenoid sinus → separate into A/S half & P/I half
- A/S
- Opthalmic division
- Branch into ANT ethmoidal
- P/I
- Maxillary division
- Branches of greater/lesser palatine N
