objective 10 Flashcards
Has a characteristic shape - funnels sound waves into the external
auditory canal
Consists of moveable cartilage and skin
* Ends at the tympanic membrane
* Lined with glands that secrete cerumen (yellow, waxy material)
* Cerumen forms a sticky barrier that helps keep foreign
bodies from entering the ear and reaching the tympanic
membrane
* Cerumen moves out to the meatus by the movements of
chewing and talking
external ear
outer third of the canal
cartilage
inner two thirds
bone covered by thin sensitive skin
Separates the external ear and the middle ear
* Oval, slightly concave, and is slightly pulled in the center by the
malleus
tympanic membrane
what are the 3 parts of the malleus
umbo
manubrium
short process
small, slack superior section of the tympanic membrane
pars flaccida
remainder of the tympanic membrane which is thicker and
more taunt
pars tensa
outer fibrous rim
annulus
tiny air-filled cavity inside the
temporal bone
* Contains auditory ossicles: malleus, incus,
stapes
* Has several openings:
* Outer ear
* Inner ear
* Eustachian tube
middle ear
covered by tympanic membrane
outer ear
oval window and the round window
inner ear
connects the middle ear to the nasopharynx; allows the passage of air
eustachian tube
what are the 3 functions of the middle ear?
Conducts sound vibrations -conducts them from the outer ear
to the central hearing apparatus in the inner ear
* Protects the inner ear - reduces the amplitude of sound
* Eustachian tube allows equalization of air pressure on each
side of the eardrum - prevents rupture of the membrane
Embedded in bone, contains the Bony Labyrinth:
* Vestibule and semicircular canals:
* Cochlea:
* is not accessible to direct examination, however
the functions of the inner ear can be assessed.
inner ear
holds the sensory organs for equilibrium and hearing
bony labyrinth
constitute the vestibular apparatus
vestibule and semicircular canals
contains central hearing apparatus
cochlea
what are the 3 divisions of the auditory system?
peripheral
brain stem
cerebral cortex
ear transmits sound, converts vibrations into
electrical impulses which are analyzed by the brain
peripheral
Binaural interaction – allows a person to locate the
direction of a sound and identify the sound
brain stem
Interprets the meaning of the sound and
begins the immediate response
cerebral cortex
what are the pathways of hearing
Air Conduction (normal pathway)
* Bone Conduction (alternative route)
what are the types of hearing loss?
Transmission of sound is obstructed and impairs hearing
* Conductive hearing loss (p. 361)
* Sensorineural hearing loss: (p. 361)
* Mixed loss: (p. 362)
This type of hearing loss is due to a
mechanical dysfunction of the external ear or middle ear
conductive hearing loss
This type of hearing loss indicates
pathology of the inner ear, cranial nerve VIII, or the auditory areas of
the cerebral cortex
sensorineural hearing loss
This type of hearing loss is a combination of
conductive and sensorineural hearing loss in the same ear
mixed hearing loss
impacted cerumen, foreign bodies, perforated eardrum,
pus or serum in the middle ear, otosclerosis
conductive
presbycusis, ototoxic medications
sensorineural
Labyrinth sends information to the brain about the
position of the body.
* If the labyrinth becomes inflamed, the wrong
information is sent to the brain.
* This causes the person to have a staggering gate and
vertigo (strong spinning, whirling sensation)
equilibrium
what is the structure of an infants ear?
Inner ear begins to develop at 5th week of gestation
* If the mother develops a rubella infection in the first
trimester - can cause damage to the organ of corti and
impair hearing of the infant
* Infant’s Eustachian tube is relatively shorter, wider, and has
a more horizontal position than an adult’s
* Infant’s lumen easily occluded by lymphoid tissue that
surrounds it
* Increased risk of middle ear infections due to differences
in Eustachian tube and easily occluded lumen
* In infants and young children, the external auditory canal is
shorter and has an opposite slope (in comparison to an adults)
what is the structure of an elder adults ear?
Cilia lining the ear canal becomes coarse and still
* Cerumen is drier - due to atrophy of the apocrine glands
* Eardrum: may appear whiter, more opaque, and duller; repeated ear
infections may have resulted in scarring on the eardrum
* Hearing loss: Impacted cerumen & exposure to noise pollution over years
can be causes
* Persons affected by presbycusis usually have a loss of hearing involving
high-tone frequencies
* May have pendulous earlobes with linear wrinkling
* Due to loss of elasticity of the pinna
how do we prep to assess an ear?
Position the client - sitting up straight with head at
examiner’s eye level.
* Check the ear canal for cerumen:
* If present and partially filling the ear canal, further
intervention will be needed. Cerumen will obstruct your
view of the eardrum
what equipment do we need for an ear exam?
Otoscope with a bright light
* Pneumatic bulb attachment (used sometimes with
infants/young children)
what are the normal size and shape for the ear?
ears equal in size bilaterally; no
swelling; no thickening
what are the abnormal findings for the size and shape of the ear?
Microtia -ears smaller than 4 cm
vertically.
* Macrotia -ears larger than 10 cm
vertically.
* Edema - swelling
what are the normal findings of the skin of the ear?
skin colour consistent with client’s facial skin; skin
intact with no lumps or lesions
what are the abnormal skin findings of the ear?
Reddened, warm skin - inflammation
* Crusts and scaling - otitis externa eczema, contact
dermatitis
* Red-blue discolouration - frostbite
what are the normal findings when checking the ear for tenderness?
feels firm and movement does not cause pain
what are the abnormal findings when assessing the ear for tenderness?
pain with movement (occurs with otitis media)
how do we assess the auditory meatus and what is normal?
Assess the size of the opening
* No redness, swelling or discharge should be noted
* Cerumen is often present
* Colour and texture will vary
* Colour: gray-yellow to light brown and black
* Texture: moist and waxy to dry and desiccated
* Presence in larger amounts will obscure assessment of the
canal and eardrum
how do we inspect with the otoscope?
Assess the external canal for redness, lesions, foreign bodies, or
discharge.
* Chose the appropriate size speculum for the ear canal.
* Tilt client’s head slightly away from examiner toward the opposite
shoulder
* Pull the pinna up and back (older children and adults)
Hold the pinna gently but firmly – do not release traction until the
examination is finished and the otoscope is removed.
* The examiner holds the otoscope upside down along their
fingers.
* The dorsa of the examiner’s hand should be along the client’s
cheek to brace the otoscope.
* Insert the speculum slowly and carefully along axis of the canal.
* Avoid touching inner bony section of the canal wall
* The examiner will watch the insertion and then put their eye up
to otoscope.
* Position the otoscope to view the tympanic membrane.
what are the normal findings of the eardrum?
shiny, translucent,
pearly gray colour, cone shaped light
reflex is prominent in the
anteroinferior quadrant (right
eardrum - 5:00 position; left eardrum
- 7:00 position)
Eardrum is flat; slightly pulled at the center
tympanic membrane intact
what are the abnormal findings of the eardrum?
yellow-amber
eardrum discolouration, redness,
swelling, absence or distortion of
landmarks
retracted eardrum, bulging eardrum, perforation
what is the whispered voice test?
Test one ear at a time
* Mask sound in the ear not being tested
* Place finger on the tragus and push in and out
* The examiner stands 2 feet behind the client
* The examiner exhales fully, and slowly whispers a set of three random
numbers and letters such as “4 D 9”
* Findings:
* Normal: client repeats each number/letter correctly when said.
* If not, repeat the test using different letters/numbers.
* Passing score: correct repetition of at least 3/6 possible numbers or
letters
* Abnormal: Inability to hear whispered words
what is the romberg test?
Used to assess the ability of the
vestibular apparatus to help maintain
standing balance.
* This test is also used as part of the
neurological system assessment and
will be discussed in that system
* Description of the test [p. 717]
