hearing Flashcards
first portion of the ear to develop is the
inner ear
inner ear begins to form at _____ after fertilization as a thickening of the surface ectoderm, called
_______ that appear on either side of the
________.
22 days; otic placodes
rhombencephalon (hindbrain)
otic placodes invaginate quickly to form the
otic pits
The otic pits pinch off from the surface
ectoderm to form the ________ within the
______of the head.
otic vesicles; mesenchyme
middle ear develops from
1st pharyngeal puch
auditory ossicles develop from
1st and 2nd pharyngeal arches
external ear develops from
1st pharyngeal cleft
separates the middle ear and external ear
tympanic membrane
this collects sound waves and conducts them to the tympanic membrane
external ear
parts of external ear
auricle
external auditory canal
middle ear conveys sound vibrations to the ________
oval window
this conveys sound vibrations to the oval window
middle ear
middle ear serves as an _______ and _______ matching device
amplifier and impedance
middle ear receives sensory innervation mediated by
CN IX
parts of middle ear
tympanic cavity
tympanic membrane
auditory ossicles
eustachian tube
the internal ear houses the receptors for
hearing and equilibrium
the internal ear is derived from _____ of the _____
otic placode of the rhombencephalon
the internal ear is located within the ________ of the ______
bony labyrinth of the temporal bone
part of internal ear
labyrinth
vestibule and organ of conti
parts of outer ear
auricle (pinna)
external auditory meatus
the outer 1/3 of the EAC is surrounded by ______ and the outer 2/3 is by
cartilage
mastoid bone
function of EAC
allows air to warm before reaching TM and isolates TM from physical damage
the tympanic membrane changes _____ to ______ energy
acoustic to mechanical energy
3 layers of tympanic membrane
- outer squamous
- middle fibrous
- inner mucosal
these conduct sound waves from the TM to the oval window of the inner ear
audtiory ossicles
auditory ossicles
malleus, incus and stapes
skeletal musscles attached to the auditory ossicles
tensor tympani and stapedius
attachment of stapedius muscle
stapes
the stapedius muscle contracts in response to loud sounds this is
acoustic reflex
built in earplugs
stapedius muscle
absent acoustic reflex could signal
conductive loss or marked sensorineural loss
the middle ear functions as an impedance matching device by
amplifying the sound pressure
Mucous-lined, connects middle ear cavity to
nasopharynx
eustachian tube
the eustachian tube connects the _______ to ______
mid ear to nasopharynx
function of eustachian tube to middle ear
it equalizes air pressure on both sides of the ear drum
the eustachian tube is normally
closed
functions of eustachian tube
- ventilates tympanic cavity and air cells
- equalizes pressure diff b/n tympanic cavity and atmosphere
- drain mid ear spaces
- creates a barrier to ascending infection
the cochlea houses the
organ of corti
end organ of hearing
organ of corti
where hair cells attach
tectorial membrane
the osseous labyrinth contains
perilymph
perilymph is located at
osseous labyrinth
membranous labyrinth contains
endolymph
endolymph is located at
membranous labyrinth
most effective
sound waves are those that are transmitted
across the ___ and the ______ to the
oval window
drumhead; ossicles
As the sound pressure displaces the perilymph,
it results in _______, and a traveling wave is propagated
from the base to the apex of the _____
deformation of the basilar
membrane; cochlea
Displacement of the basilar membrane causes
movement of the Organ of Corti and its hair cells
The fluid-filled cochlea tends to ____ as they progress down its length, so that
waves dissipate before reaching the _______
dampen the
waves; helicotrema
Mechanical energy of the stapes footplate
motion is converted into
electrical impulse
acoustic energy in the form of sound waves, is
channeled into the ear canal by the
pinna
Malleus, which is attached to the TM, starts
the
ossicles in motion
stapes moves in and out of the ________ creating a fluid motin or hydraulic energy
oval window of the cochlea
auditory pathway
- 8th nerve
- cochlear nuclei
- superior olivary
- nucleus
- lateral lemniscus
- inferiour colliculus
- medial geniculate body
- auditory cortex
where all or almost all the auditor fibers
synapse.
inferior colliculus
The Auditory cortex is within the ______ lobe
of the brain
temporal
tolerable sound is from _____ to _____-
0-140 dB
pitch is related to a sound’s _______
vibration frequency
pitch is measured in
cycles per second
sound characterized by a definite pitch
of harmonic combination of pitches
tone
process wherein the perception of a
sound event can be diminished by other
simultaneous or near -simultaneous sound
events
masking
low frequency is stimulated at
apex of cochlea
high frequency is stimulated at
base of cochlea
refers to the maintenance of the
position of the body (mainly the head) relative to the
force of gravity.
static equilibrium
maintenance of body
position (mainly the head) in response to rotational
acceleration or deceleration
dynamic equilibrium
receptor organs for equilibrium
vestibular apparatus
vestibular apparatus includes
semicircular ducts
utricle
saccule
the semicircular ducts contain
cristae
semicircular ducts is the site of hair cells for _______
dynamic equilibrium
the utricle and saccule contains ____, site of hair cells for ______
macula, static equilibrium
mechanic of balance involves
inner ear
retina of the eye
musculoskeletal
CNS
the semicircular canals are sensitive to ______
rotation (angular acceleration)
sensitive to linear motion and to changes in head position relative to gravity
otolith organs
utriculus (utricle) is located in the
horizontal plane of the head
saccule is located in the
vertical plane
functions of the sense of equilibrium
spatial orientation
balance control
visual image stabilization
fast,
uncontrollable movements of the eyes
nystagmus