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Chapter 14, Lesson 4
Guided Reading Activity 53
Ears and Hearing Protection
1.
What are the three main sections of the
ear?
The outer ear
The middle ear
The inner ear
2a. List the function of each part
of the outer ear:
• Auricle: Helps
channel sound
waves into the
external auditory
canal.
Auricle--------
2b. List the function of each part
of the outer ear:
• External auditory
canal: Leads to the
eardrum.
External auditory canal------------------------------
2c. List the function of each part
of the outer ear:
• Hairs and wax:
Protects the ear
from dust and
foreign objects.
2d. List the function of each part
of the outer ear:
• Tympanic
Membrane: a
barrier between
the outer ear and
the middle ear.
Tympanic Membrane:
3a. Answer the following about
the middle ear:
• What are the
auditory
ossicles?
– Thee small
Incus or Anvil------------------------bones linked
Stapes or Stirrup---------------together that
connect the Malleous or Hammer------------------------eardrum to the
inner ear.
3b. Answer the following about
the middle ear:
• What does the
eustachian tube do?
– Connects the middle
ear to the throat.
– Allows pressure to
be equalized on
either side of the
eardrum when you
swallow or yawn.
eustachian tube------------------
4a. Answer the following
questions about the inner ear.
• The Labyrinth.
– Also called the
inner ear.
– A network of
curved spiral
passages.
4b. Answer the following questions about the
inner ear.
• Describe the shape
and function of the
cochlea.
– Spiral-shaped canal
– The area of hearing in
the inner ear where
balance is controlled.
Cochlea------------------------
5. Describe how hearing occurs.
• Sound waves enter the external
auditory canal and cause the eardrum
to vibrate
• Vibrations cause fluid in the cochlea to
move
• This stimulates receptor cells to send a
nerve impulse to the brain.
• The brain interprets the sound.
6. Describe how your ears help
you maintain your balance.
• Tiny hairs located in
the crista sense
movement and send
nerve impulses to
the brain.
• The brain then
signals muscles to
make adjustments
to maintain balance.
Crista------------------------Semicircular canals
7. List four ways to help keep
your ears healthy.
• Clean them regularly.
• Protect the outer ear from injury and extreme
cold.
• Wear protective gear such as batting helmets
when playing sports.
• Wear a hat that covers both the auricles and
the earlobes in cold weather.
• Keep foreign objects out of the ear.
• Have ear infections treated immediately.
• Avoid loud noise.
8. Name the two categories of
hearing loss.
• Conductive
• Sensorineural
9. Conductive hearing loss.
• What is it?
– Sound waves are not passed from the
outer to the inner ear.
• What is the most common cause of
hearing difficulties in children?
– The build up of fluid within the middle ear,
often due to infection.
10. Sensorineural hearing loss.
• Causes
– Damage to the cochlea, the auditory nerve or the
brain.
• What is tinnitus?
– Ringing, buzzing, whistling, roaring, hissing, or
other sound is heard in the ear in the absence of
external sound.
• What are the causes of tinnitus?
– Natural aging
– High blood pressure
– Overexposure to loud noise.
11. List three steps to protect
your ears from tinnitus.
• Lower the volume of the source of the
noise.
• Wear earplugs in noisy environments.
• Limit the length of time you are exposed to
loud noise.