ENT Flashcards
What is the function of the eustachian tube?
Connects the middle ear and the nasopharynx
Equalises pressure between the middle ear and the atmosphere
Also drains mucus from the middle ear
Which cranial nerve supplies the tongue with the majority of motor function?
Hypoglossal nerve (CN12, XII)
What supplies motor function to the palatoglossus?
Vagus nerve (CN10, X)
What is the main role of palatoglossus?
Initiating swallowing
Also elevates the posterior tongue
Which cranial nerve supplies taste and sensation to the posterior 1/3 of the tongue?
Glossopharyngeal (CN9, IX)
Which cranial nerve supplies taste to the anterior 2/3 of the tongue?
Chorda tympani branch of the facial nerve (CN7, VII)
Which cranial nerve supplies sensation to the anterior 2/3 of the tongue?
Lingual branch of the trigeminal nerve (CN5, V)
Which direction does the cone of light point when looking at the tympanic membrane?
Anteroinferiorly
Absence of the light reflex in the ear could be a sign of?
Could be normal
Or increased pressure within the inner ear (e.g. otitis media)
Which cranial nerve innervates the tensor tympani?
Trigeminal nerve (CN5, V)
Remember TTT
(Medial pterygoid, branch of mandibular nerve, V₃)
What is a cholesteatoma?
Accumulation of keratinising squamous epithelial cells
What makes up the lateral 1/3 of the external ear canal?
Skin and cartilage, contains sebaceous and ceruminous glands (produces wax) and hairs
What makes up the medial 2/3 of the external ear?
Skin and bone, no hairs and no wax
Where does skin of the external ear canal grow from?
The umbo of the tympanic membrane, outwards
What are the 3 layers of the tympanic membrane?
Outer, continuous with skin of the EAC
Middle, fibrous layer
Inner, respiratory epithelium (ciliated columnar epithelium with goblet cells)
What conducts sound waves from the tympanic membrane to the inner ear?
Ossicles, much more important in sound conduction than the tympanic membrane
What three bones make up the ossicles?
Malleus
Incus
Stapes
What lines the middle ear?
Same continuous respiratory epithelium that forms the inner layer of the tympanic membrane
What does the facial nerve supply?
Motor to muscles of facial expression
Taste to anterior 2/3 of the tongue (via chorda tympani)
What complications can arise from cholesteatoma?
They grow and are destructive. Can cause damage to the bony ossicles
What are the semicircular canals responsible for?
Detecting head rotation
What is the saccule responsible for?
Detecting linear acceleration in the vertical plane
What is the utricle responsible for?
Detecting linear acceleration in the horizontal plane
What can cause otitis media with effusion?
Chronic dysfunction of the eustachian tube, relative negative pressure in the middle ear and retraction of the tympanic membrane
What two tuning fork tests are there?
Weber’s - tests lateralisation
Rinnie - compares air/bone conduction
What are the different types of audiometry?
Pure tone audiometry Visual reinforcement audiometry (6mth-3yrs) Play audiometry (3-6yrs)
What is presbycusis?
Most common type of Sensorineural Hearing Loss
Natural aging
Occurs gradually and starts with loss of higher frequencies
What is tympanometry?
Air forced into the air canal to make the eardrum move
Measures the mobility of the eardrum
Can help detect fluid, perforation or blockage
Management of hearing loss?
Sound amplification
Direct stimulus of cochlear nerve cells
Surgery of outer and middle ear
What types of hearing aid are there?
Open fit Bone anchored (BAHA)
What conditions of the inner ear can affect balance?
Benign paroxysmal positional vertigo
Vestibular neuritis
Meniere’s disease
What common clinical condition can also affect balance?
Migraine
How can you treat otitis media with effusion (glue ear)?
Hearing aids or grommets
Most improve within 3 months on their own
Why are children more prone to ear infections than adults?
Eustachian tube is flat in children, easier for bacteria to get into the ear
45 degree angle in adults.
Also adenoidal hypertrophy
What can cause painful/discharging ears?
Otitis externa
Acute otitis media
Chronic otitis media
Cholesteatoma
How would you treat otitis externa?
Topical antibiotics
Water precautions
How would you treat otitis media?
Antibiotics (co-amoxiclav)
Grommets and adenoidectomy if chronic
When would you suspect cholesteatoma?
Hearing loss despite grommets
Chronic discharging ear
What counts as a normal number of URTI episodes in children?
8 episodes per year up to 15 days
What is epistaxis?
Nosebleed
Epistaxis management?
First aid, pinch top of nose and tilt head forwards
Cauterisation if chronic
Tonsillitis?
Bacterial or viral
Risk of glomerulonephritis, peritonsillar abscess
Treat with antibiotics if bacterial
History of a child with airway problems?
Emergency History of foreign body Recent illness Feeding problems Stridor
