Transcript Somatic and Special Senses

Somatic and Special
Senses
Anatomy Ch. 10 Part III
Sense of Hearing
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Mr. Henderson- “Take your hat off in the
hall.”
student- (no response)
Mr. Henderson- “Excuse me child, I said take
your hat off in the hall!”
Student- “Ok, ok, you don’t have to tell me
twice, take it easy!”
Ear has inner, middle and external
parts
External Ear
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2 parts:
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1. auricle-outer, funnel shaped structure
2. External auditory meatus- S shaped tube
leading inwards thru temporal bone
Fig. 10.7
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Auricle collects sounds waves and directs
them into the external auditory meatus
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Vibrating vocal cords produce voice
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http://videos.howstuffworks.com/hsw/12677breaking-the-silence-how-sound-reaches-ourears-video.htm
Parts of the ear
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HowStuffWorks
Videos "Exploring
Sound: Parts of the
Ear"
Middle Ear
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Eardrum (tympanic membrane)
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Has skin on outer side, mucous membrane on
inner side
Cone-shaped
Malleus (bone) is attached to it
Don’t put Q-tips in ear to clean it out-could
rupture eardrum! Nothing smaller than your
finger should go in your ear.
Auditory ossicles (bones): Fig 10.8
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Malleus-vibrates with eardrum. Then the
vibration is passed on to the incus, which
passes it on to the stapes.
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These bones also amplify the sounds to the
oval window.
drums solo - Google Video
Role of the Auditory Tube
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To equalize pressure on both sides of the
eardrum
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Drains to throat
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Helps with altitude changes
How the ear works
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TeacherTube - 1. How
the ear works
Inner Ear
Fig. 10.9
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Each ear has 2 labyrinths (osseous and
membranous)
Membranous is inside osseous
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3 semicircular canals-provide equilibrium
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Cochlea-functions in hearing
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Inner ear anatomy
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You can detect sound wave frequencies from
20-20,000 or more vibrations per second.
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See Table 10.1, page 274 which sums up
hearing something
The Bat!
They use echolocation to catch their prey
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HowStuffWorks
Videos "Exploring
Sound: Echo Location"
Hearing-decibels
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Whispering: 40dB
Normal conversation: 60-70 dB
At 120 dB (a rock concert), produces
discomfort
At 140 dB, produces pain (jet takeoff)
Frequent exposure above 90 can lead to
hearing loss. What? 
Equilibrium Fig. 10.12
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Static equilibrium-maintain stability and
posture
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Dynamic equilibrium-moving or in motion,
helps with balance
Static equilibrium
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Organs utricle and
saccule, inside
membranous labyrinth
(Fig. 10.9)
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Fig. 10.12
Dynamic Equilibrium
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cats funny - Google
Video
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Johnson wins floor
exercise for third gold AOL Video
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The 3 semicircular canals detect motion of the
head and body and aid in balancing in sudden
movement.
Motion sickness
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Organs of equilibrium
are disturbed