Download The Anatomy of the Ear

The Anatomy of
the Ear
The Outer Ear
1. Auricle (Pinna)
2. External Auditory
Canal (ear canal)
• Channels sound into
the ear
The Middle Ear
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Notes:
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How We Hear
http://www.hearingcenteronline.com/ear2.shtml
CONGENITAL Disorders
A disorder that is present at birth.
Can be hereditary (such as a genetic
syndrome like Treacher Collin’s
Syndrome). Or, can be from another
source - like when fetus is affected by
maternal Rubella.
Conductive Hearing
Loss
Occurs when there exists
a complication
somewhere between the
outer ear and the middle
ear.
Sensorineural Hearing
Loss
A loss affecting an
inner ear structure or
the auditory nerve.
Typically a permanent
loss.
How Sound Travels Thru the Ear
• Sound enters the auricle. The alternating
pattern of high/low pressure is entered in
here: pressure wave.
• Then into the ear canal. This is 2 cm
long.
• Then the ear drum. At this point
pressure wave is transformed to
mechanical wave (this is converted to
vibrations).
Then into the middle ear…
• Then to the 3 tiny bones (also called the
ossicles). The names of the bones are:
malleus (hammer), incus (anvil), and stapes
(stirrups).
• As it reaches the stapes, mechanical wave
transforms to compression wave within the
fluid. The stapes gives off 15 times more
vibrations than that of the ear drum.
Eustachian Tube
• Is air filled cavity – it allows for
equalization of pressure.
And the Inner Ear…
• Once it enters the oval window,
sound enters two areas: cochlea
and semicircular canals.
• Thru the cochlea which is lined with
20,000 hair-like nerve cells (it is the
most critical role in the ability to
hear). This is where more amplitude
of vibration occurs. Compression
wave transforms to electrical impulse.
And Finally…….
• Then it passes thru the auditory nerve to the
brain – capable of interpreting qualities of
sound upon reception of electric nerve
impulses.
Meniere’s Disease
• Meniere's disease is a disorder of the
inner ear which causes episodes of
vertigo, ringing in the ears (tinnitus), a
feeling of fullness or pressure in the ear,
and fluctuating hearing loss. It is
difficult to live with and can often cause
victims to seek psychological help.
Symptoms of Meniere’s Disease
• Vertigo, balance problems,
• Loss of low pitches
Who has Meniere’s Disease?
•
•
•
•
Alan Shepard
Emily Dickinson
Van Vough
Martin Luthor
Meningitis
• Meningitis is a medical condition caused
by inflammation of the protective
membranes covering the brain and spinal
cord, known collectively as the meninges.
• Diagnosed with use of a spinal tap.
• Symptoms: severe pain in the ear,
irritability, and fever, headaches, and
sometimes a purplish rash.
Otitis Media
• Otitis media is an infection or
inflammation of the middle ear.
• This inflammation often begins when
infections that cause sore throats, colds,
or other respiratory or breathing
problems spread to the middle ear.
• Otitis Media, continued….
• It is very isolating.
• Teens who have it are not aware that there is
anyone else out there suffering from the
same problems.
• Symptoms include severe pain in the ear,
irritability, and fever.
• This affects children’s speech between 3
months and 3 years.
A famous person
• Lou Ferrigno “The Incredible Hulk” had
Otitis Media and lost his hearing to this
disease.
Ototoxicity
• A poisoning of the ear.
• Ototoxicity is damage of the ear (oto),
specifically the cochlea or auditory nerve
and sometimes the vestibulum, by a toxin
(often medication).
• Symptoms: Severe pain in the ear,
irritability, and fever
Otosclerosis
• Otosclerosis is the abnormal growth of bone
of the middle ear. This bone prevents
structures within the ear from working
properly and causes hearing loss.
• Symptoms: Severe tinnitus, recurring
auditory memories, and frequent vertigo.
Did you know?
• William Peterson of CSI: Las Vegas has
Otosclerosis and a deaf mother in real
life!
Rubella
• Also known as German Measles or “3-day
measles”
• an infection that primarily affects the skin
and lymph nodes
• usually transmitted by droplets from the nose
or throat that others breathe in
German Measles
• Symptoms include a red rash covering the
upper body, fever, and headaches.
Treacher Collin’s Syndrome
• Treacher Collins syndrome is a genetic,
craniofacial birth defect that is characterized
by a range of distinctive facial anomalies.
• The main characteristics of TCS are
downward slanting eyes, small lower jaw,
and malformed or missing ears.
• These anomalies can cause hearing,
breathing, and eating problems.
Symptoms and Treatments
• Characterized by auricles that are small
or low on the head, eyes that are sunken
and droopy, and a cleft palete.
• It can be treated with hearing tests
and/or plastic surgery.
Usher’s Syndrome
• Usher syndrome is the most common
condition that affects both hearing and
vision starting with peripheral vision.
• Usher syndrome is inherited, which means
that it is passed from parents to their
children through genes.
Usher’s Syndrome
• It can affect an unborn infant and cause them to be
deaf and/or blind if their mother comes in contact
with someone who has it.
• It is not a common disease because both parents
must have the gene.
• It occurs 4 in 100,000 births. Usher syndrome is
inherited, which means that it is passed from
parents to their children through genes.
Things to complete:
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Parts of the Ear Diagram WS
Parts of the Ear (fill in the blank) WS
Study Medical Terms Signs
QUIZ: October 30/31!!!