Hearing and Balance Disorder Flashcards
approx. 2.5 cm long, lateral third: elastic cartilaginous & dense fibrous framework, medial two-thirds: bone lined with thin skin, ends at the tympanic membrane.
External auditory canal
separates middle from external ear
Typanic membrane (eardeum)
secrete a brown, waxlike substance: cerumen/ear wax
Ceruminous glands
anterior to the external auditory canal; the head of the mandible can be felt by placing a fingertip in the external auditory canal while the patient opens and closes the mouth.
Temporomandibular Joint (TMJ)
composed mainly of cartilage, except for the fat and subcutaneous tissue in the earlobe, collects the sound waves and directs vibrations into the external auditory canal.
Auricle
air-filled cavity, includes the tympanic membrane laterally and the otic capsule medially.
Middle ear
which is approximately 1 mm wide and 35 mm long, connects the middle ear to the nasopharynx.
Esutachian tube
the eustachian tube opens by the action of the ______ when the person performs a Valsalva maneuver, yawns, or swallows.
tensor veli palatini muscle
It drains normal and abnormal secretions of the middle ear and equalizes pressure in the middle ear with that of the atmosphere.
Estachian tube
about 1 cm in diameter, very thin, pearly gray, translucent; protects the middle ear and conducts sound vibrations from the external canal to the ossicles; sound pressure is magnified 22 times.
Tympanic membrane (eardrum)
Assist in the transmission of sound.
Ossicles
3 smallest bones in the ears
malleus (hammer)
incus (anvil)
stapes (stirrup)
Separate the middle from the inner
2 fenestrae (oval, round window)
sits in the oval window, transmits sound to the
inner ear
Footplate of the stapes
The footplate of the stapes is secured by the_____
Fibrous annulus
provides an exit for sound vibrations`
Round window
3 layers of the typanic membrane
Outer layer
Fibrous middle layer
Inner mucosal layer
80% composed of all three layers of the typanic membrane
Pars tensa
20% lacks the middle layer
Pars fllaccida`
True or false: The absence of this fibrous middle layer makes the pars flaccida more vulnerable to pathologic disorders than the pars tensa
TRUE
The cochlea and semicircular canals are housed in the
Bony labyrinth
The cochlea and semicircular canals are housed in the
Bony labyrinth
surrounds and protects the membranous labyrinth
Bony labyrinth
The fluid that baths the membranous labyrinth
Perilymph
Membranous Labyrinth : utricle, saccule,
cochlear duct, semicircular canals, organ of
Corti (all of which are surrounded by a fluid
called _____)
endolymph
posterior, superior, and lateral, which lie at 90-degree angles to one another—contain sensory receptor organs, arranged to detect rotational movement
3 semicircular canals
The _____ and ______ are involved with linear movements.
utricle and saccule
housed in the cochlea, a snail-shaped, bony tube about 3.5 cm long with two and a half spiral turns.
Organ of corti
separate the cochlear duct (scala media) from the scala vestibuli and the scala tympani from the basilar membrane
Organ of Corti membranes
also called the end organ for hearing
Organ of Corti
Hearing is conducted over two pathways:
air and bone
Manipulation of the auricle, does not cause pain, if with pain, _______ is suspected
external otitis
The tympanic membrane is inspected with an ____
otoscope
indirect palpation is done with a _______
pneumatic otoscope
general estimate of hearing can be made by assessing the patient’s ability to hear a whispered phrase or a ticking watch, testing one ear at a time.
Evaluation of Gross Auditory Acuity -
Test: the examiner whispers softly from a distance of 1 or 2 feet from the unoccluded ear and out of the patient’s sight. The patient with normal acuity can correctly repeat what was whispered.
Whisper test
Test: - bone conduction to test lateralization of sound; detecting unilateral hearing loss. A tuning fork (ideally, 512 Hz), set in motion by grasping it firmly by its stem and tapping it on the examiner’s knee or hand, is placed on the patient’s head or forehead A person with normal hearing hears the sound equally in both ears or describes the sound as centered in
the middle of the head.
Weber Test
such as from otosclerosis or otitis media, hears the sound better in the affected ear in weber test
Conductive hearing loss
resulting from damage to the cochlear or vestibulocochlear nerve hears the sound in the better-hearing ear in weber test
Sensorineural hearing loss