7.1 Anatomy of the Nose and Paranasal Sinuses Flashcards
List 4 functions of the nose
1) Olfaction
2) Respiration
3) Filter and humidify
4) Drain & eliminate paranasal sinus and nasolacrimal duct secretions
5) Humidifies air
6) Defence mechanism, preventing pathogen entry
How much mucus does your nose produce every day?
1.5 litres
What is the function of the external nose?
Provides opening into nasal cavity
Describe the structure of the external nose
Bony and (predominantly) cartilaginous components
Nostrils bounded laterally by alae
Skin covering nose extends into the vestibule
What are the little hard hairs inside the external nose and state their function
Vibrissae which function to stop foreign particles and dust entering nose
Lable the components of the external ear shown on the image below
What are the openings into the nasal cavity?
Nares (nostrils)
What is the central bone (green) indicated by the arrow?
Vomer: thin sheath of bone which forms part of the nasal septum (this is part bone part cartilage)
What is the hole in the centre of the skull
Piriform aperture: where the bony and cartilaginous bits join
Name the bone located in the centre of the Piriform aperture
Vomer
List all 8 bones contributing to the skeleton of the nose (FINE SHVP)
Frontal
Nasal
Ethmoid (plus its perpendicular plate)
Sphenoid
Vomer
Palatine process of maxilla
Horizontal process of palatine bone
Inferior concha
Label the 3 improtant cartilages of the external nose skeleton and label them on the image below
1) Upper lateral cartilages
2) Lower lateral cartilages
3) Septal cartilage
What is the most common facial fracture and how may it occur?
Nasal fracture: usually by force to the face
What does a nasal fracture result in and list a complication that may arise as a result of this
Deformity of the nose: doesn’t usually cause a large amount of problem with breathing, the bigger problem is usually cosmetic ONLY
Complication: Septal haematoma
What is a septal haematoma and how would it appear?
What may occur if it goes untreated?
Main consequence of a nose fracture. A collection of blood builds up between cartilage of septum and the mucosa
Soft cherry tomato appearance
If untreated we can get necrosis and collapse of the cartilage and changes in the bridges
List 2 ways in which we treat a nasal fracture?
1) Manipulation (early): within 3 weeks in order to prevent bone resetting in the deformed shape
2) Septorhinoplasty (late) after the 3 week mark when deformed bone shape is permanent
What is the hole at the back that joins the nose to the nasopharynx
What may occur if this hole doesn’t open up in babies
Choanea
If this hole doesn’t open up in babies it results in an inability to breathe
What is the lining of the nasal cavity?
All mucosal lining which is continuous with areas draining into the cavity
EXCEPT for vestibule which is covered in skin
Label the image below
What 3 structures comprise the Medial wall (nasal septum)?
Perpendicular plate of the ethmoid bone
Vomer bone
Septal cartilage
What comprises the lateral wall of the nasal cavity?
3 Turbinates (conchae) which function to filter and humidify air:
- Superior, Middle and Inferior Turbinates
** Inferior is a bone of its own, Other 2 are part of the ethmoid bone.
What do the Turbinates (conchae) create?
5 passages within the cavity called meatuses:
1) Inferior meatus
2) Middle meatus
3) Superior meatus
4) Spheno-ethmoidal recess
5) *one passageway which pass down the middle
Above which turbinate is the spheno-ethmoidal recess located?
Above the Superior turbinate
What is located laterally on both sides of the Ethmoid bone?
How are these joined?
Ethmoidal sinuses located laterally on the ethmoid bone joined by cribriform plate