Ear Anatomy and Hearing Loss Quiz

Study Notes

Ear Anatomy and Function

The ear has three main areas: external, middle, and inner ear.
The ear's functions are hearing and equilibrium (balance).

Hearing Loss

Hearing loss is partial or total inability to hear, diagnosed when an individual cannot hear 25 decibels in an ear.
Classifications of hearing loss include conductive loss, sensorineural (perceptive) loss, mixed (combined) hearing loss, sudden sensorineural hearing loss, and presbycusis.
Conductive hearing loss occurs when sound cannot reach the inner ear due to interference with sound transmission.
Sensorineural hearing loss occurs when the inner ear or cochlear portion of CN VIII is unable to function.
Presbycusis is progressive bilateral perceptive hearing loss associated with aging.

Risk Factors for Hearing Loss

Conductive hearing loss: cerumen impaction, foreign body in the external canal, otitis externa, trauma, otitis media, otosclerosis, tumors.
Sensorineural hearing loss: trauma, CNS infections, degenerative conditions, vascular issues, ototoxic drugs, tumors.

Meniere's Disease

A chronic disorder of the inner ear due to distention of the endolymphatic compartment.
The classic triad is progressive hearing loss with each attack + vertigo + tinnitus.
Management aims to reduce endolymphatic distension.

Earwax and Infections

Cerumen is earwax produced by sebaceous and ceruminous glands in external auditory canals.
Cerumen impaction can cause a feeling of fullness in the ear, otalgia, itching, tinnitus, conductive hearing loss, and inability to visualize the tympanic membrane.
Otitis externa is inflammation/infection of the external ear.
Common bacterial causes of otitis externa are Pseudomonas aeruginosa and Staphylococcus aureus.
Clinical features of otitis externa include otalgia, otorrhoea, intermittent hearing loss, itching, aural fullness, peri-auricular lymphadenopathy, and a red and swollen ear canal.

Otitis Media

Inflammation and infection of the middle ear by pathogens via a dysfunctional Eustachian tube.
Classifications include acute OM, serous (secretory) OM, and OM with effusion.
Most commonly affects children aged 3-10 years old.
Chronic suppurative otitis media is a persistent ear infection that results in tearing or perforation of the eardrum.
Serous otitis media is a blockage of the Eustachian tube causing negative pressure and transudation of fluid from blood vessels, developing effusion in the middle ear.
Risk factors include children with cleft palate, premature birth, and formula-fed infants.
Tympanocentesis is a surgical intervention for otitis media used for culture.
Tubal myringotomy is a surgical intervention for otitis media with effusion.

Additional Conditions

Otosclerosis is a condition where bones of the ear become immovable, causing deafness as the stapes fuses with the bone of the ear.
Tinnitus is ringing in the ear, caused by wax buildup, infection, and exposure to loud sounds.

Inner Ear

The cochlea is located in the inner ear, within the temporal bone.
Hair cells in the organ of Corti act as receptors, transmitting impulses to the auditory cortex.
Continued stimulation can cause adaptation in hearing.

Treatments

Conductive hearing loss is often treated by addressing the cause, such as removing cerumen impaction.
Sensorineural hearing loss is often treated with hearing aids, cochlear implants, and management of underlying conditions.

Tympanic Reflex

The tympanic reflex is a protective mechanism that helps to prevent damage to the middle ear from loud noises.

Description

Test your knowledge on the anatomy of the ear, its functions, and the various types of hearing loss. This quiz covers key concepts such as conductive and sensorineural hearing loss, risk factors, and the impact of aging on hearing abilities. Perfect for students and anyone interested in audiology.