Chapter 9/10

Question 1

What is the purpose of the ear?

Answer 1

The ear as a transducer that changes acoustic energy into electrochemical energy (sound-mechanical-electrical)

Question 2

Pinna

Answer 2

A collector of sound energy, cartilage, covered with epithelial tissue with fine hair, helps with localization, resonating cavity, funnels sound into ME

Question 3

Concha

Answer 3

Deepest depression

Question 4

Helix

Answer 4

Rim-like ridge surrounding pinna

Question 5

Antihelix

Answer 5

Runs inside the helix

Question 6

Tragus

Answer 6

cartilage on anterior wall

Question 7

Antitragus

Answer 7

Opposite of the tragus, bottom ridge on concha

Question 8

External Auditory Meatus (Ear Canal)

Answer 8

7 mm diameter, 2.5 cm length, resonating cavity, lateral 1/3 cartilage, medial 2/3 bon meatus, s shaped, lined with hair in outer 1/3, secretes cerumen

Question 9

Tympanic membrane

Answer 9

Eardrum, sits with a tilt, 3 layers (epithlial, fibrus, mucous), separates OE from ME, can see the beginning of the ossicles

Question 10

What is acoustic energy?

Answer 10

The disturbance of energy which passes through a material in the form of waves (through any medium)

Question 11

What happens in the ossicles?

Answer 11

The acoustic energy is transferred into mechanical energy

Question 12

What are the most important muscles in the ME?

Answer 12

Tensor Tympani Muscle, Stapedius muscle

Question 13

Malleus

Answer 13

largest, attaches to Tm

Question 14

Incus

Answer 14

connects malleus and stapes, saddle joint

Question 15

Stapes

Answer 15

connects the oval window, smallest

Question 16

What is the purpose of the ossicular chain?

Answer 16

To transmit acoustic energy across the bones from the TM to the inner ear

Question 17

Is the ME filed with air?

Answer 17

Yes

Question 18

What is the ME function?

Answer 18

To increase the pressure appreaching the cochlear (impedence)/match the impedence of the 2 systems (OE and cochlea)

Question 19

Impedance

Answer 19

Overcoming resistance to flow of energy

Question 20

How does the ME overcome impedence?

Answer 20

Total area from TM to OW is a 25 db gain–> lever action is 2 db and bucking is 4-6 db

Question 21

What is mechanical energy?

Answer 21

The energy of an object due to its motion or position (sum of kinetic and potential energy)

Question 22

What is the purpose of the IE?

Answer 22

Sensor for balance and hearing

Question 23

Balance

Answer 23

Vestibular

Question 24

Hearing

Answer 24

Cochlear

Question 25

The bony labyrinth

Answer 25

vestibue, ssc, cochlea

Question 26

What is the outer bony labyrinth lined with ?

Answer 26

perioseum

Question 27

Wha is the function of the vestibular system?

Answer 27

It gives us an idea of where we are in space. When the head turns, fluid in one or more ssc ducts pushes against the cupula and bends the cilia of the hair cells- fluid in the corresponding ssc on the opposite side moves in the opposite direction

Question 28

Periosteum

Answer 28

A complex structure composed on an outer fibrous layer that lends structural integrity and inner cambium later that possess osteogenic potential

Question 29

Basilar Membrane

Answer 29

extra cellular matrix that lines the basal side of epithelial and endothelia tissues- it produces physical and biochemical cues to the cells (it is made of basal lamina and reticular lamina)

Question 30

Vestibular membrane

Answer 30

membrane inside the cochlea of the inner ear and it separates the cochlear duct from the vestibular duct (dividing wall)

Question 31

Where does fluid of the IE come from?

Answer 31

Perilymphtic fluid is secreted by the epithelial lining of the bony labryinth

Question 32

Is the cochlear filled with fluid?

Answer 32

yes

Question 33

IE (cochlea) function

Answer 33

the cochlea is specifically designed to sort out the frequency components of an incoming signal, determine amplitude, and identify basic temporal aspects of that signal. The BM carries the traveling sound wave which the movement of the hair cells is creating

Question 34

How do the waves work?

Answer 34

Different frequencies reach their peak as different positions along the membrane (base= high apex=low)

Question 35

What is the vestibulocochlear nerve? (VIII)

Answer 35

1. Vestibular branch- carries info from receptors in the IE responsible for equilibrium 2. Cochlear branch- carries info from receptors in the cochlea responsible for hearing

Question 36

Where is the signal initialy registered?

Answer 36

In the brainstem (pons and medulla)

Question 37

Otitis Media

Answer 37

Fluid in ME, Eustachian tube not draining, ME bones are anaerobic (without air), pressure is not equalized (negative)

Question 38

Mastoiditis

Answer 38

Inflammation/infection of the mastoid bone (could lead to deafness, infection in the brain, or death), bacteria is coming from the eustachian tube

Question 39

Otitis Externa

Answer 39

Inflammation of the skin of the external ear, swelling, swimmers ear, facial paralysis bc the root of the nerve is close to the inner ear, hearing loss

Question 40

Other pathologies

Answer 40

OM, OE, congenial issues, traumatic lesions, neoplastic changes, tumors, bone changes, ssc dehiscence

Question 41

Tympanometry

Answer 41

Impedance of the ME

Question 42

High Resolution MRI

Answer 42

Structural Architechture

Question 43

Clinical Audiometry

Answer 43

Behavioral Assessment of hearing/screenings

Question 44

Evoked Auditory Brainstem response

Answer 44

integrity of the early stages of the auditory pathway

Question 45

Electrocochleography

Answer 45

integrity of the auditory pathway

Question 46

Functional Magnetic Resonance Imaging

Answer 46

auditory cortical functioning

Question 47

Otoacoustic Emissions Testing

Answer 47

tones into the ear, reflections from the cochlea/health of hair cells