Ears, nose & throat

Question 1

Ear anatomy - outter ear

Answer 1

Question 2

Ear anatomy - middle ear

Answer 2

Question 3

Ear anatomy - inner ear

Answer 3

Question 4

CLOZE
The outer ear functions to direct sound waves into the auditory canal
Sound waves travelling through air amplified by tympanic membrane
Sound waves transmitted from air-filled middle ear must be converted into pressure waves in fluid in inner ear (cochlea)
Cochlea controls hearing whilst vestibular system controls balance – both work by mechanical to electrical signal transduction

Question 5

CLOZE:
The cochlea consists of a series of ducts called the scala vestibuli, scala tympani and scala media
Scala vestibuli and tympani are filled with perilymph, whilst scala media filled with endolymph, and which contains the organ of corti

Question 6

The Organ of Corti contains inner and outer hair cells, which are the sites of auditory transduction
What do the inner and outer hair cells do

Answer 6

Inner hair cells are responsible for signalling to the brain via the cochlea nerve, outer hair cells act as amplifiers
The bodies of the hair cells are in contact with auditory nerve fibres, and the cilia of the hair cells are in contact with the tectorial membrane

Question 7

Vibration of basilar membrane activates inner and outer hair cells (sensory receptors) by causing bending of stereocilia

Answer 7

Vibration of basilar membrane activates inner and outer hair cells (sensory receptors) by causing bending of stereocilia (next slide)
When inner hair cells are depolarized, excitatory neurotransmitter (glutamate) is released to activate afferent cochlear auditory nerves
When inner hair cells are hyperpolarized, afferent cochlear auditory nerves are inhibited

Question 8

Ear: hair cell function

Question 9

cloze
Conditions of the ear
Ear wax build up (not infection/condition)
Outer ear inflammation (otitis externa): conductive hearing loss
Middle ear inflammation (otitis media): conductive hearing loss
Inner ear inflammation (labryinthitis and vestibular neuronitis/neuritis): sensorineural hearing loss causing inner ear dizziness

Question 10

Drugs used in management of ear disorders - name atleats five

Answer 10

Antibiotics (neomycin, flucloxacillin, amoxicillin, clarithromycin, erythromycin – see also Spring term PM1PY5)
Anti-histamines (cinnarizine, cyclizine, promethazine teoclate – next lecture)
Anaesthetics (lidocaine – will cover more in Autumn term PM3PY2)
Analgesics (paracetamol, ibuprofen – cover more in Autumn term PM3PY2),
Anti-fungals (clotrimazole – PM1PY5, PM3PY3)
Anti-infectives (clioquinol - PM3PY3)
Anti-inflammatories (corticosteroids – dexamethasone, flumetasone; NSAID – phenazone [also analgesic and anti-pyretic] – PM1PY5, PM3PY3)
Astringents and acids (aluminium acetate and acetic acid – PM1PY5)
Cerumenolytic agents (olive oil, almond oil, sodium bicarb, sodium chloride, arachis oil, urea hydrogen peroxide)
D2 receptor antagonists (prochlorperazine – cover S1 PM3PY2)

Question 11

How to examine the ear

Answer 11

• Otoscopes used to examine ear canal and tympanic membrane
• Usually monocular
• Can visualise e.g. shows bulgng or tympanic membrane

Question 12

Ear wax (outer ear) symptoms, diagnosis and treatment

Answer 12

Question 13

Otitis externa : symptoms, signs, cause, diagnosis and ACUTE OE treatment

Answer 13

• CAUSE: bacteria, fungal
• SIGNS: red, swollen ear canal, cellulitis, erythema of tympanic membrane
• SYM: pain or tenderness, itching, discharge, hearing loss, jaw pain
• DIAG: Signs 2+, symptoms 1+
• TM:

Question 14

Otitis externa treatment when chronic or more severe

Answer 14

• They may take a swab to identidy causative organism
• IF SPREADING: Flucloxacilin SEVEN days ((or clarithromycin if penicillin-allergic).

Question 15

Otitis media: cause, symptoms, diagnosis and treatment

Answer 15

• CAUSE: When the eustachian tube becomes inflammed or blocked (middle ear), usually caused by virus but can be bacteria. Traps fluid in the middle ear which can be infected
• SYM: Typically presents as a sudden onset of otalgia (earache), fever, and hearing loss, often preceded by URTI lasting for several days. Also vomiting, discharge, diarrhoea, fullness/pressure in the ear
• DIAG: Acute onset of symptoms (e.g., earache in older children/adults)
  On otoscopic exam – red/yellow/cloudy tympanic membrane, mod-severe bulging of tympanic membrane, perforation or discharge in canal

Question 16

Treatment for chronic otitis media

Answer 16

Chronic inflammation, perforated ear drum and otorrhea
Referred to specialist ENT
Usually require antibiotics and topical steroids

Question 17

Labryinthitis & vestibular neuritis/neuronitis (inner ear): cause, symptoms, diagnosis and treatment

Answer 17

• Inflammation of inner ear (labyrinthitis) or vestibular nerve (vestibular neuritis)
• CAUSE: Viral infection (rarely bacteria). Also caused by stress and ototoxicity
• SYM: Inner ear dizziness associated with vertigo, balance disorder, nausea, tinnitus (both) in addition to hearing loss (labyrinthitis only)
• SIGNS: Nystagmus, may use head impulse test in diagnosis
• DIAG: Clinical signs/symptoms

Question 18

Two types of hearing loss

Answer 18

Sensorineural hearing loss is caused by damage to the hair cells of the cochlea or the damage to the auditory nerve: this is permanent as human hair cells cannot regenerate

Conductive hearing loss is due to sounds not being transmitted from outer to inner ear – e.g. due to blockage. Can be permanent or temporary

Question 19

Causes of hearing loss

Answer 19

Question 20

Examples of ototoxic drugs

Answer 20

Question 21

Which type of hearing loss can hearing aids help

Answer 21

Hearing aids: there are many types, such as behind the ear, in ear and in canal. Can be used for conductive and sensorineural hearing loss (depending on the case). Amplify sounds to aid hearing.

Question 22

How do implants aid hearing loss

Answer 22

• Loads of types e.g. cochlear implant, middle ear implant, auditory brain stem implant
• Cochlear implants, typically for more severe sensorineural hearing loss (damage/loss of hair cells) and in profound deafness.