Nose Flashcards
What are the functions of the nose?
Olfaction Route for inspired air Filters air Moistens and warms air Resonating chamber for speech
What is the nose vestibule?
Bit just inside nostril - lined with skin
Has sebaceous glands and hairs
What makes up the floor of the nasal cavity?
Hard (maxilla and palatine bones) and soft palate (muscles and CT)
What is the external nose made of?
Hyaline cartilage
Bone = nasal and frontal process of maxilla
What is the most commonly fractured bone in the face?
Nasal bone
What forms the lateral wall of nasal cavity?
Maxilla - with bony projections (conchae)
What is the medial boundary of the nasal cavity?
Nasal septum
What makes up the nasal septum?
Anterior = cartilage
Vomer - bone coming up from floor
Perpendicular plate of ethmoid bone
What makes the roof of the nasal cavity?
Bones - frontal, ethmoid and sphenoid
What is the crista galli?
Bony projection superiorly on the ethmoid bone
Thin and sharp
Into anterior fossa of cranium
Describe a septal haematoma
Rare
Trauma to nose - bucking of septum and shearing of vessels
Blood accumulation between perichondrium and cartilage - AVN or pressure necrosis
Must examine for
Unilateral or bilateral
What Mx does a septal haematoma need?
Drain it and pack it
Make sure blood doesn’t accumulate again and press perichondrium back to cartilage
How do you get a saddle-nose deformity?
Untreated septal haematoma leading to AVN of cartilaginous septum
How many conchae do we have and what are they called?
3
Superior, middle and inferior
What type of epithelium covers the conchae?
Pseudostratified columnar ciliated with goblet cells
What is the spheno-ethmoid recess?
Right above superior concha
Sphenoid sinus drains here
Where does the maxillary sinus drain?
Middle meatus
General sensation to nasal cavity is via …
Trigeminal nerve
V1 and V2
What are nasal polyps?
Fleshy, benign swellings arising form nasal mucosa
Usually bilateral
How do nasal polyps typically present?
Age > 40 yrs Blocked nose and rhinorrhoea Post-nasal drips Decreased smell and taste Bilateral
What would make you suspect a tumour over a nasal polyp?
Unilateral
Blood tinged secretion
How do we know if we are touching a polyp or a concha?
Polyp = mobile and won't hurt to touch Concha = immobile and will hurt to touch
What is rhinitis?
Inflammation of the nasal mucosal lining
What are the Sx of rhinitis?
Nasal congestion Sneezing Rhinorrhoea Irritation Post-nasal drip
What is the arterial supply to the medial and lateral walls of the nasal cavity?
Ophthalmic artery (ICA) Maxillary artery (ECA)
What do we call the point of anastomosis in the anterior septum?
Kiesselbach’s triangle
Little’s area
Why is Kiesselbach’s triangle important?
Most common source of bleeding in epistaxis
90%
What is the first method of stopping a nose bleed?
Pinch nasal septum (just past bridge)
Lean forward
Venous drainage from the nasal cavity goes to …
Cavernous sinus
Facial vein > IJV
Pterygoid plexus
What is the pterygoid plexus?
Large venous plexus between the temporalis muscle and the lateral pterygoid muscle
What are the branches of the ophthlamic artery that supply the nose?
Anterior ethmoid
Posterior ethmoid
What is the sphenopalatine artery?
Right at back of nasal cavity
Branch of maxillary artery
5% of nose bleeds
What are the para-nasal sinuses?
Air filled spaces - extensions of the nasal cavity
Lined with resp mucosa
Named according to bone found it
What is the purpose of nasal sinuses?
Humidify and warm air
Reduce weight of skull
Where do most of the paranasal sinuses drain?
Middle meatus
Which sinus is most commonly affected with sinusitis and why?
Maxillary sinus
Hard to drain as duct is at top - must be full or go against gravity - therefore blocks easily
What are ethmoid air cells and why are they of significance?
Air cells in medial wall of orbit
Infections can pass from ethmoid sinus into orbit
Dental abscesses and infections can spread into …
Maxillary sinus
Describe acute sinusitis
Inflammation lasting < 4 weeks
Commonly infective and often secondary to viral infection of nasal cavity
Usually self limiting
Describe the Hx/examination of someone with sinusitis
Cold/flu like Sx Pyrexia Rhinorrhoea (green/yellow) Headache/facial pain worse on leaning forward Blocked nose
What histological effects does a primary infection of the nasal cavity have?
Decreased ciliary function
Oedema of mucosa and ostia
Increased nasal secretions
What are the most likely types of organism to cause sinusitis?
Strep
Haemophilus
Which nerves innervate the sinuses?
Maxillary sinus = maxillary branch trigeminal (V2)
Other sinuses = ophthlamic branch trigeminal (V1)
What epithelium lies on the tongue?
Stratified squamous non-keratinised
The SNS to the nasal cavity comes form …
T1
Ascend on carotid artery
What regulates blood flow to nasal mucosa?
Pterygopalatine ganglion
PNS (largely greater petrosal nerve)
