Nose & Sinus Anatomy and Physiology Flashcards
1
Q
Function of nasal airway?
A
- Warm and humidify inhaled air
- Turbinates and septum
- Laminar flow
- Mucosal lining
- Humidification
- Sinuses are a reservoir of warm humid air
- Turbinates and septum
- Important for neonates
2
Q
How is the nasal airway able to act as immune barrier?
A
- Specialised nasal mucosal lining
- First 1/3 stratified squamous epithelium
- Nasal hairs trap large particulates
- Posterior 2/3 pseudostratified columnar epithelium
- Cilia allows mucus to travel 2.5cm/min
- Goblet create sticky mucus that trap pathogens
- Mucus contains IgA, IgE (allergies), lysozymes, alkaline
- First 1/3 stratified squamous epithelium
3
Q
What is the structure of the nasal epithelium?
A
- First 1/3 stratified squamous epithelium
- Nasal hairs trap large particulates
- Posterior 2/3 pseudostratified columnar epithelium
- Cilia allows mucus to travel 2.5cm/min
- Goblet create sticky mucus that trap pathogens
- Mucus contains IgA, IgE (allergies), lysozymes, alkaline
4
Q
What does mucus contain?
A
- Mucus contains IgA, IgE (allergies), lysozymes, alkaline
5
Q
Through what does smell occur?
A
- Olfactory nerve
- Through cribrifom plate
- Olfactory mucosa
6
Q
What allows drainage and aeration of middle ear?
A
Drainage and aeration of middle ear:
- Eustachian tube
7
Q
What are some functions of sinuses?
A
- Reservoir of warm humid air
- Lighten skull
- Crumple zones
- Vocal resonance
- Lined with same mucosa (immune barrier)
8
Q
What are some of the external subunits of the nose?
A
- Columella
- Tip and supratip
- Dorsum
- Nasion
- Glabella
9
Q
What are examples of common nasal trauma?
A
- Broken bones
- Move back before they heal
- Broken/bent cartilage
- Cannot be easily unbent
10
Q
What fors the following of the nasal passage:
- roof
- walls
- floor
A
Roof:
- Skullbase/cribiform plate
Walls:
- Turbinates
Floor:
- Hard palate
11
Q
What are some internal nasal associated structures?
A
- Paranasal sinuses
- Orbits
- Lamina papyracea
- Eustachian tube
- Adenoids
12
Q
What is the midline of the nose?
A
Septum
13
Q
What is the septum formed from?
A
Bone and cartilage:
- Septal cartilage
- Vomer
- Perpendicular plate of ethmoid
14
Q
Where does nasal cartilage get blood supply from?
A
- Poor blood supply
- Gets blood supply from mucosa overlying it
- Relevant in septal haematoma
15
Q
Septal haematoma - pathology
A
Septal haematoma = blood collects in the septum
16
Q
Septal haematoma - aetiology
A
- Post trauma
17
Q
Septal haematoma - presentation
A
- Almost always bilateral
- No blood supply to septum
- Causes septum necrosis, leading to perforation so needs to be drained as soon as possible
18
Q
What are turbinates?
A
Bony skull like projections from lateral wall of the nose:
- Superior
- Middle
- Inferior
19
Q
What is the function of turbinates?
A
Increases surface area of the nose:
- Humidification and warming of air
20
Q
What are turbinates covered in?
A
Covered in erectile tissue:
- Day to day cycling
- Respond to temperature
21
Q
What opens underneath turbinates?
A
Sinuses and nasolacrimal duct open underneath turbinates:
- Meatus
- Correspond to turbinate they are under
22
Q
What is the nasolacrimal duct?
A
Drainage pathway of lacrimal secretions (tears)
From lacrimal sac
23
Q
Where does nasolacrimal duct open?
A
Opens under inferior turbinate
Inferior meatus
24
Q
What are the paranasal sinuses?
A
-
2 frontal
- Behind eyebrows
- Drains into frontal recess
- Drains via middle meatus
- Lateral to middle turbinate
-
2 maxillary
- Behind each cheek
- Drains via middle meatus
-
Sphenoid
- Drains via the sphenoethmoidal recess
- Optic nerve runs above it
- Internal carotids either side
- Pituitary is posterior
- This is why severe sinusitis can cause neurological problems
-
Ethmoid air cells (anterior and posterior)
- Honeycomb structure between eyes
- Middle turbinate turns at the back of the nose to attach to the lateral nasal wall
- This turn is called the ground lamella
- Anterior to this is the anterior ethmoid which drains into the middle meatus
- Posterior to this is the posterior ethmoids which drains into the superior meatus
- Clinical relevance is that infections spreads to orbit causing periorbital/orbital cellulitis
25
Where are the frontal sinuses located?
* Behind eyebrows
* Lateral to middle turbinate
26
What do the frontal sinuses drain and drain via?
* Drains into frontal recess
* Drains via middle meatus
27
Where are the maxillary sinuses located?
* Behind each cheek
28
What do the maxillary sinuses drain via?
* Drains via middle meatus
29
What does the sphenoid sinus drain via?
* Drains via the sphenoethmoidal recess
30
What structures are found around the sphenoid sinus?
* Optic nerve runs above it
* Internal carotids either side
* Pituitary is posterior
* This is why severe sinusitis can cause neurological problems
31
Where are the ethmoid air cells?
* Honeycomb structure between eyes
32
What is the ground lamella?
* Middle turbinate turns at the back of the nose to attach to the lateral nasal wall
* This turn is called the **ground lamella**
* Anterior to this is the anterior ethmoid which drains into the middle meatus
* Posterior to this is the posterior ethmoids which drains into the superior meatus
33
What does the anterior and posterior ethmoid air cells drain via?
* Anterior to this is the anterior ethmoid which drains into the middle meatus
* Posterior to this is the posterior ethmoids which drains into the superior meatus
34
What is the clinical relevence of the ethmoid air cells anatomy?
* Clinical relevance is that infections spreads to orbit causing periorbital/orbital cellulitis
35
What sinuses drain via the following:
- middle meatus
- superior meatus
- sphenoethmoidal recess
- inferior meatus
* Frontal, anterior ethmoids and maxillary
* Middle meatus
* Posterior ethmoids
* Superior meatus
* Sphenoid
* Sphenoethmoidal recess
* Nasolacrimal duct
* Inferior meatus
36
What is sinusitis?
Sinusitis = inflammation of the sinuses
37
Sinusitis - aetiology
Can be due to allergies or infection
38
Sinusitis - complications
Normally self limiting (acute being less than 12 weeks)
Occasionally is chronic:
* Inflammation blocks sinus drainage
* Mucus in sinus gets infected causing more inflammation
* Can lead to polys causing further blockage
39
Sinusitis - treatment
* Medical management
* Remove allergic triggers, with or without antihistamines
* Treat infection
* Reduce inflammation
* Steroids (long term nasal spray)
* Surgery
* Remove polyps
* Open up sinus drainage pathways
* Risks
* Damage lamina papyracea (orbital damage)
* Damage to skull base (cerebrospinal fluid leak and meningitis)
40
What are risks of surgery for sinusitis?
* Damage lamina papyracea (orbital damage)
* Damage to skull base (cerebrospinal fluid leak and meningitis)
41
Where does the nose receive blood supply from?
Has excellent blood supply from internal and external carotid
External:
* Sphenopalatine artery (via maxillary)
* Also greater palatine (via maxillary) and superior labial (via facial)
Internal:
* Anterior and posterior ethmoidal artery (via ophthalmic)
42
Describe the nasal innervation of the nose?
Almost all trigeminal nerve (CN V):
* V1 ophthalmic
* V2 maxillary
Sensation is internal and external
43
What is found in the post-nasal space?
Adenoids:
* Waldeyers ring
Eustacian tube opening
Soft palate muscles attach to Eustachian tube to open it during swallow:
* Equalise middle ear
