1 50: 12.3 Clinical Application Smell and Taste Disorders 54: Lab 31 Smell and Taste Lab 55: Hearing Case Study: No More Loud Music (Read/Highlight/Questions)

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• 50: 12.3 Clinical Application Smell and Taste Disorders• 54: Lab 31 Smell and Taste Lab• 55: Hearing Case Study: No More Loud Music

(Read/Highlight/Questions)• 56: External Ear Picture (color-coded---

Functions)• 56: Now Hear This: Don’t Remove Earwax

(Read/Highlight/Questions)• 58: Middle Ear Picture (color-coded---Functions)• 60: All About Ear Infections (ONLY Highlight)• 62: Inner Ear Picture (color-coded---Functions)

Tape in Notebook 5 mins

Sponge: Set up Cornell Notes on pg. 63

Topic:

12.5: Major Parts of the Inner Ear

Essential Questions:

Picture Bubble Map of Inner Ear:• Cochlea• Semicircular canals• Osseous Labyrinth• Membranous Labyrinth• Vestibule• Vestibulocochlear Nerve

2.1 Atoms, Ions, and Molecules

12.5: Major Parts of the Inner Ear

QUIZ: On MONDAYLabeling the parts of the external, middle, and inner ear

Extra Credit:• IB Art Show @ mall• Little Mermaid • Tonight 6pm • Sat 2pm

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Inner Ear

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Inner Ear

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Inner EarThe Inner Ear is a complex system of labyrinths

• Osseous (bony) labyrinth • rigid outer wall of inner ear• secretes perilymph which

conducts sound vibrations

• Membranous labyrinth• tube within osseous

labyrinth• filled with endolymph which

conducts sounds• Houses receptor cells for

hearing and equilibrium

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Inner EarThree Parts of Labyrinths:

• 1. Cochlea (coke/le/ah) or (Kok/le/ah)

• functions in hearing

• 2. Semicircular canals• provides a sense of

equilibrium

• 3. Vestibule• functions in

equilibrium AND hearing

cochlea

Semicircular canals

vestibule

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The Vestibulocochlear Nerve:Aka acoustic or auditory nerve

• Has two branches:

1. vestibular branch: senses changes in the position of the head to maintain equilibrium

2. cochlear branch: send signals to brain where sound can be interpreted

Cochlea

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ScalaVestibuli

ScalaTympani

Cochlear Duct

Vestibular Membrane

Basilar Membrane

Organ of Corti

• Leave a little room for info about cochlea

Pg. 62

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CochleaCochlea• Functions in hearing• Shaped like a snail• Coiled around a bony core (modiolus)

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CochleaScala vestibuli

• upper compartment of cochlea• leads from oval window to apex of spiral• conducts sound vibrations to the scala media (cochlear duct)• contains perilymph

Oval window

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CochleaScala tympani

• lower compartment• extends from apex of the cochlea to round window• allows the vibrations to escape into the air of the tympanic cavity• contains perilymph

Round window

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CochleaVestibular membrane

• separates cochlear duct from scala vestibuli

• Separates endo/perilymph• Diffusion barrier- allows

nutrients to travel from perilymph to endolymph

Cochlear duct aka scala media• lies between the scala vestibuli

and scala tympani• Filled with endolymph• Houses the organ of Corti

Basilar membrane• separates cochlear duct from

scala tympani• Floor of cochlear duct• Separates the endo/perilymph

Scala Vestibuli

Scala Tympani

endolymph

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Organ of Corti***Organ of Corti***:•Hair cells: hearing receptor cells located here •on upper surface of basilar membrane•Different frequencies of vibration move different parts of basilar membrane•Sound frequencies cause hairs of receptor cells to bend•Simulates the vestibulocochlear nerve which will send the signals to the brain for interpretation

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Tympanic Membrane Cochlea Incus Tympanic Cavity AuricleStapes Round Window Malleus Auditory Tube

Semicircular Canals Vestibulocochlear Nerve External Acoustic Meatus

Label this diagram of the Ear*Quiz on Mon.

Pg. 62

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Tympanic Membrane Cochlea Incus Tympanic Cavity AuricleStapes Round Window Malleus Auditory Tube

Semicircular Canals Vestibulocochlear Nerve External Acoustic Meatus

Label this diagram of the Ear*Quiz on Mon.

Pg. 62

Auricle

Incus

malleus

Tympanic membrane

stapes

Semicircular canals

cochlea

Vestibulocochlear nerve

Round window

Tympanic cavityAuditory tube

External acoustic meatus

Sponge: Set up Cornell Notes on pg. 65

Topic:

12.5: How Sound Travels Through the Inner Ear

Essential Questions:• NONE.

2.1 Atoms, Ions, and Molecules

12.5: How Sound Travels Through the Inner Ear

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Ear Labeling Quiz Time 15pts

13. 14. 15.

1. The stapes vibrations enter the perilymph at the oval window 2. Travel along the scala vestibuli3. Enter the endolymph of the cochlear duct4. Move the basilar membrane

a. Causing the hair cells in the Organ of Corti to bendb. Send signals along the vestibulocochlear nerve to the brain

5. Vibrations enter the perilymph of the scala tympani6. Forces are dissipated into the air in the tympanic cavity

DON’TWRITE

1. Sound waves vibrate the tympanic membrane2. The tympanic membrane vibrates the auditory ossicles3. The vibrations enter the perilymph (fluid in the scala vestibule and scala tympani) at the oval window 4. Travel along the scala vestibule (top compartment of cochlea)5. Enter the endolymph (fluid in the cochlear duct) of the cochlear duct6. These vibrations move the basilar membrane

a. Frequencies cause organ of corti to bend against the tectorial membrane

b. Vesicles in hair cells release neurotransmittersc. Neurotransmitters stimulates the ends of nearby sensory nerve fibersd. Impulse travels along the cochlear branch of the vestibulocochlear

nervee. To the medulla oblongataf. Through the midbrain g. To the thalamush. Into auditory cortices of the temporal lobes of the cerebrum

(BRAIN) where they are interpreted7. Vibrations enter the perilymph of the scala tympani8. Forces are dissipated into the air in the tympanic cavity by movement of the round window

Inner Ear Animation Video

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Cochlear Implant

• Implant placed under skin above the ear

• Leads to electrodes placed near auditory nerve in the cochlea

• Wear a head set that has a microphone to pick up incoming sounds

• Sends electrical signals to cochlea

• Auditory nerve is stimulated

Cochlear Implants 3m7s

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8 mo. Old Deaf Baby with Cochlear Implants 49s

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http://www.youtube.com/watch?v=HTzTt1VnHRM

Bionic EarsStart at (4m42s)

4m10s

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Clinical Application 12.4:Getting a Cochlear Implant