Download Do You Hear What I Hear?

Do You Hear What I Hear?
Outer Ear
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Pinna (auricle) – visible
part of the ear (function is
to collect sound waves)
External auditory cannal –
your ear canal
Tympanic Membrane –
your ear drum and it
separates the outer and
middle ear
Outer Ear
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Auditory canal is lined
with sebaceous glandscalled ceruminous glands
which produce cerumen
Cerumen – ear wax
Function – is to protect the
ear
Middle Ear
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A.
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Cavity in the temporal
bone
Connects with the pharynx
by the Eustachian tube –
which equilizes pressure
in the middle ear with the
outside atmosphere
Middle Ear
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Contains the 3 smallest
bones in the body which
transmit sound waves to
the inner ear:
 Malleus (Hammer)
 Incus (Anvil)
 Stapes (Stirrup)
Inner Ear
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Cochlea – Spiral – shaped
organ of hearing
Cochlea contains a
membraneous tube, the
cochlea duct, which is filled
with fluid that vibrates
when sound waves are
transmitted by the stapes
(they strike against it)
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Inner Ear
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Organ of Corti – delicate
hair-like cells that pick up
vibrations of fluid and
transmit them as a sensory
impulse along the auditory
nerve to the brain
Inner Ear
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Semicircular Canals – three
structures in inner ear that
contain liquid set in motion
by head and body
movements
Impulses are sent back to the
cerebellum to help maintain
body balance (equilibrium)
Nothing to do with hearing
Pathway of Hearing
External auditory canal
Tympanic membrane
incus, and stapes)
Auditory nerve
Ossicles (malleus,
cochlea
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Hearing is very fragile and
loud noises over a long period
of time can cause hearing loss
Delicate hair cells in the organ
of Corti become damaged if
over-stimulated
Symptoms are:
Tinnitus (ringing in the ears)
Difficulty understanding what
people are saying
Hearing Loss
Hearing Loss
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2 types of hearing loss:
Conductive – sounds are
prevented from reaching the
middle ear (ear wax, fluid in
the middle ear or abnormal
bone growth)
Sensorinueral – problem with
inner ear and/or auditory
nerve (sometimes can be
treated with cochlear
implants)
Presbycusis
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Condition which
causes deafness due to
the aging process
Lose the ability to hear
low frequencies first
Can be helped with
hearing aide
Otitis Media
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Infection of the middle
ear
Often a complication
of the common cold in
children
Treatment: antibiotics
Otitis Media
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Repeated bouts of otitis
media can cause a build up
of fluid or pus
Myringotomy – tubes are
inserted through the
tympanic membrane to
relieve pressure and drain
off fluid
Otosclerosis
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Inherited disorder that is a
common cause of deafness
in young adults
Chronic progressive disease
of the middle ear
Stapes becomes spongy and
then hardens, becoming
fixed and immobile
Treatment: Stapedectomy
and total replacement of the
stapes
Meniere’s Disease
Affects the semicircular canals
 Attacks occur without any
warning
 Symptoms:
Marked vertigo (dizziness)
Nausea and Vomiting
Tinnitus
Treatment includes bedrest during
and acute attack and medication
to relieve vertigo and nausea
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Tinnitus
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Ringing of ears from
impacted wax, otitis
media, otosclerosis,
loud noise, blockage of
normal blood supply to
the cochlea, and a
reaction to drugs
(salicylates)