Class notes ears

Question 1

Overall ear function:

Answer 1

hearing; equilibrium

Question 2

External auditory canal terminates at the?

Answer 2

Tympanic membrane (TM)

Question 3

Internal ear is made of?

Answer 3

Outer 1/3 is cartilage

Inner 2/3 tunnels through temporal bone

Question 4

tympanic mem. separates?

Answer 4

TM separates external and middle ear.

Question 5

Lymphatic drainage of external ear flow is?

Answer 5

to the parotid, mastoid, and superficial cervical nodes

Question 6

Middle ear is:

Answer 6

Air-filled cavity inside temporal bone

Question 7

Eustachian tube

Answer 7

connects middle ear with nasopharynx and allows passage of air. Normally closed—opens with swallowing or yawning.

Question 8

3 functions of middle ear:

Answer 8

Conducts sound vibrations from outer to inner ear.
Protects inner ear by reducing sound amplitude.
Eustachian tube allows equalization of air pressure on each side of the TM so TM does not rupture.

Question 9

Inner ear contains:

Answer 9

Contains bony labyrinth which holds sensory organs for equilibrium and hearing.

Question 10

Cochlea contains:

Answer 10

contains central hearing apparatus (inner ear)

Question 11

Function of hearing (3 levels):

Answer 11

peripheral; brainstem; cerebral cortex

Question 12

Peripheral level:

Answer 12

Sound transmission
Vibrations converted into electrical impulses for analysis by the brain.
Electrical impulses conducted by the auditory portion of CN VIII to the brainstem.

Question 13

Brainstem function:

Answer 13

binaural interaction—locating direction of sound in space—identifying the sound

Question 14

Cerebral cortex:

Answer 14

interprets the meaning of the sound and begins the appropriate response.

Question 15

Normal pathway of hearing is

Answer 15

by air conduction.

Question 16

Alternative route is

Answer 16

by bone conduction (through vibration of skull bones).

Question 17

Conductive loss caused by:

Answer 17

impacted cerumen; foreign body; perforated TM; pus/blood in middle ear; otosclerosis (↓ mobility of the ossicles). Can by treated by increasing amplitude.

Question 18

Sensorineural (perceptive) loss caused by:

Answer 18

patho of inner ear, CN VIII, or auditory areas of cerebral cortex; gradual nerve degeneration that occurs with age.

Question 19

Three semicircular canals (labyrinth) in inner ear function:

Answer 19

input to brain about your postion in space

Question 20

Inflamed labyrinth causes:

Answer 20

wrong signals to brain—vertigo

Question 21

Infants and young children eustachian tube is:

Answer 21

shorter, wider, more horizontal

Question 22

Cause of otitis media in children:

Answer 22

shorter, wider, more horizontal eustachian tube

easier for pathogens from nasopharynx to get to the middle ear,

Question 23

Increased risk for middle ear infection in children:

Answer 23

Absence of breastfeeding first 3 mo. of life
Exposure to secondhand smoke
Daycare attendance
Male sex
Pacifier use
Seasonality (fall, winter)
Bottle feeding in the supine position

Question 24

For ear symptoms obj data:

Answer 24

Ask about recent URI, history of ear infections

Question 25

Otalgia is:

Answer 25

earache

Question 26

Otorrhea is:

Answer 26

ear discharge?

Question 27

tinnitus is:

Answer 27

ringing in the ears
caused by noise-induced hearing loss.
Other causes include: ear infections, disease of the heart or blood vessels, Ménière’s disease, brain tumors, emotional stress, exposure to certain medications, a previous head injury, and earwax

Question 28

What increases risk for recurrent OM in children?

Answer 28

First episode of OM that occurs within first 3 mo. of life

Question 29

Infants at risk for hearing deficit are those who were/have:

Answer 29

Exposed to maternal rubella
Exposed to maternal ototoxic drugs in utero
Premature infants
Low birth weight infants
Trauma or hypoxia at birth
Congenital liver or kidney disease

Question 30

Children at risk for hearing deficit are those who have:

Answer 30

Meningitis
Measles
Mumps
OM
Any illness with persistent high fever

Question 31

Incidence and severity of OM increased in indigenous children from:

Answer 31

No. America, Australia, New Zealand, and Northern Europe.

Question 32

Aging adult may have increased amount and drier ____ , which become impacted

Answer 32

cerumen

Question 33

Presbycusis is:

Answer 33

gradual sensorineural loss caused by nerve degeneration in the inner ear

Question 34

Presbycusis in aging adult: % and age:

Answer 34

hearing loss in 60% older than 65 years

Question 35

Clues to hearing loss:

Answer 35

Lip reading
Frowns, leans forward to hear
Postures head to catch sound
Misunderstands questions
Frequently asks you to repeat questions
Acts irritable or startled when you raise your voice
Speech is garbled
Inappropriately loud voice
Flat, monotonous tone of voice

Question 36

Testing hearing acuity in newborn:

Answer 36

Newborn: startle (Moro) reflex; acoustic blink reflex

Question 37

Testing hearing acuity 3-4 m:

Answer 37

Acoustic blink reflex; Infant stops moving and appears to “listen”. Stops sucking. Quiets if crying. Cries if quiet.

Question 38

Testing hearing acuity in 6-8m:

Answer 38

Infant turns head to localize

Question 39

Testing hearing acuity in preschool/school-age:

Answer 39

need to screen with audiometry

Question 40

In infants, children, and adults, how can hearing loss affect quality of life

Answer 40

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