Ear Flashcards
What are the 3 bones in the middle ear called?
Malleus(hammer)
Incus
Stapes (handle)
What is the process of hearing?
Sound waves to tympanic membrane, vibrations cause ossicles (bones) to move, stapes passes to labyrinth through the oval window, movement of fluid in cochlear, movement of hair cells in the cochlear, interprets sound goes to the brain via auditory (cochlear) nerve
What’s the process of balance?
Semicircular canals with endolymph, which moves and registers which plane the head is in.
Posterior - ear to shoulder
Anterior/superior - nodding ‘yes’
Lateral - shaking ‘no’
Urticle and saccule hair cells detect movements when calcium carbonate crystals move - send messages to brain.
What’s is dizziness?
Messages to brain from vestibular system even when spinning has stopped.
What is Ménière’s disease?
Lasts minuets to hours. Inner ear disorder, causes dizziness, tinnitus and loss of hearing, and fullness in the ears
Sensorineural hearing loss.
What are the features of otitis externa?
Itching, pain, discharge watery. Swelling, redness.
Rx - remove debris, abx drops and topical hydrocortisone to ear.
Swans are not useful
What is otomycosis?
Fungal infection - might see visible spores.
Colour a. Niger black, c. Albicans white, a. Fumigatis brown.
Treat with antifungals
Acute Otitis media presentation?
Pain, fever, Bulging/perforated TM, Mucopus.
Treat with oral ABX (can do myringotomy to relieve pressure)
What is a cholesteatoma?
Destructive growth of keritinised squamous epithelium. Seen as ‘wax in the attic’. Are errosive (if not treated).
Can progress to deafness. Presents with hearing loss and discharge.
Treatment - surgical removal
What is the difference between acute otitis media and Otitis media what effusion?
1st - infection
2nd - aka glue ear non-infectious - peaks at 2 years old. caused by eustation tube dysfunction, allergy, congenital eg downs, cleft palate, mucocilliary disorders eg CF.
Whats is otoslerosis and exostosis?
Bone overgrowth - in middle ear (malleus,inus, stapes) - family history.
Exostosis - bony swellings in canal seen in surfers to stop cold wind and water entering ears.
Which infections can cause congenital sensorineural hearing loss?
Rubella, CMV and toxoplasmosis
On an audiogram below what volume (Dbs) is defined as normal hearing?
Above the 20db line eg less than 20db, should be able to hear all the frequencies.
How would Conductive and SN hearing loss look on audiometry?
Con - bone normal, air way below. > 10db different
Sn - bone conduction down sloping line as freq increases. Similar pattern for air conduction. No air-bone gap.
What ear problem is associated with neurofibromatosis 2?
Bitlateral acoustic neuroma
Hearing loss, tinnitus and vertigo
