Nose, Nasal Cavity And Paransal Sinuses Flashcards
What are 3 functions of the nose and nasal cavity
- Olfaction
- Filtering + humidifying inspired air
- Drainage of secretions from Paranasal sinuses and Nasolacrimal ducts
The External nose is mainly cartilaginous.
What structures form its root?
- Frontal processes of maxillae
- 2 Nasal bones
List 3 possible injuries to the nose due to its prominent position
- Septal Haematoma
- Septal deviations (Obstruction to airflow)
- Nasal bone fractures
Describe the boundaries of the nasal cavity
- Extends from Nostrils anteriorly to Choanae posteriorly
- Has a Roof, Floor and Medial + Lateral walls
What forms the Medial wall of the nasal cavity?
Nasal septum, which consists of;
- Perpendicular plate (of ethmoid bone)
- Septal cartilage
- Vomer bone
Where does the Cartilaginous portion of Nasal Septum (septal cartilage) get its blood supply from?
Relies on overlying perichondrium
What happens in a Septal Haematoma?
Suggest a complication
(Can appear as bulge when looking into nostrils)
- Blood collects between Septal cartilage and its Perichondrium, stripping away blood supply-> ischaemia of cartilage
- Necrosis of cartilage can occur-> Saddle deformity
Why is the Lateral Wall of the bony cavity irregular?
Due to presence of Conchae (Bony projections)
Name the 3 Conchae and the spaces formed by them
How do they affect airflow?
Superior, Middle, Inferior Conchae form the Superior, Middle, Inferior Meatuses
- Slow airflow by causing turbulence
- Increased SA over which air flows, allowing better humidification
Through what holes do the Paranasal Air Sinuses and Nasolacrimal Ducts drain into Nasal Cavity?
Through openings under the meatuses (3, on lateral wall of cavity)
What 4 bones make up the roof of the nasal cavity
- Nasal
- Frontal
- Ethmoidal (Cribriform plate)
- Sphenoid (E.g Transpehnoidal surgery to reach Pit gland)
What nerve branch innervates sensory function of the nasal cavity and paransal sinuses
Vb
Describe the lining and contents of the nasal cavity
- Respiratory mucosa (Excluding Vestibule which is lined by skin)
- Olfactory region (superior) has Olfactory Mucosa and contains dendrites of Olfactory nerves
Describe the Respiratory Mucosa lining most of the Nasal Cavity
What are 3 ways air is changed in the cavity?
Pseudostratified ciliated epithelia rich in goblet cells
- Filtered (Mucus, Cilia)
- Humidified (Watery secretions)
- Warmed (Rich blood supply)
What are Nasal Polyps?
How do they present typically? (Not symptoms)
Benign swellings of Nasal Mucosa
- Usually Bilateral
- Usually seen over 40 years old
- Pale/ yellow or fleshy, reddened
List 4 symptoms of Nasal Polyps
- Blocked nose and watery rhinorrhoea (both sides)
- Post-nasal drip (watery secretions run down back of pharynx)
- Decreased smell and reduced taste
- Unilateral polyp may suggest tumour (may be blood-tinted secretion)
What is Rhinitis?
What are 4 symptoms?
(Causes: Acute infective OR allergic)
Inflammation of Nasal Mucosal lining
- Rhinorrhea (runny nose)
- Nasal congestion
- Post nasal drip
- Sneezing + Nasalirritation
Describe the blood supply to the Nasal Mucosa
Branches of Opthalmic and Maxillary arteries, which anastomose in the Anterior Septum.
This anastomosis is called Kiesselbach’s Plexus/ Little’s Area
What is the most common source of Epistaxis? (Nose bleed)
How is it treated?
Keisselbach’s Plexus (If from here, usually unilateral)
Pinching nose
Describe the venous drainage of the nasal cavity
Into Pterygoid venous plexus, Cavernous Sinus and Facial Vein
What 2 branches of Opthalmic artery feed into Keisselbach’s plexus
Name 2 branches of Maxillary artery that do so.
Ophthalmic;
- Anterior Ethmoid
- Posterior Ethmoid
Maxillary;
- Sphenopalatine (Bleed here causes some nosebleeds, is more serious and difficult to treat)
- Greater Palatine (Less important than SP)
What are the 4 major Paranasal sinuses?
These are all paired, except for which one?
Which is largest?
- Maxillary, largest
- Frontal
- Sphenoid, not paired
- Ethmoidal
What are 3 components of the Ethmoidal sinus?
Describe the Paransal sinus’ drainage into Nasal Cavity
Anterior, Middle and Posterior air cells
- Drain into a Meatus via Ostia (small channels)
- Most through Middle Meatus
Which Sinus is most commonly affected by infection?
Maxillary
