PNB Exam 4 Pt 2
conductive deafness
damage to middle or external ear (impairs all sound frequencies)
What happens when the stereocilia bend towards the kinocilium?
depolarization because K+ and Ca+ are allowed in
medial superior olive function
detectable time difference
tonotopic auditory cortex
different regions of your cortex respond to differing frequencies
Endocrine gland releases
effector hormones
sound coming in at 500 Hz with an intensity of 50 decibels vs sound coming in at 500 Hz with 150 decibels, coded
encoded at same location on cochlea, but action potentials change
cochlea filled with which liquids
endolymph (in Scala media) and paralymph (in scala vestibuli and scala tympani)
Goiter is caused from what?
enlargement of thyroid often due to over-secretion of TSH
when the stereocilia are displaced towards the kinocilium, what happens
hair cell depolarizes due to K and Ca influx
tonotopic definition
hair cells vary in their response to tone
when basilar membrane vibrates, what happens
hair cells vibrate and hit the tectorial membrane
endolymph, which surrounds ________, has really high _____ which allows for _____ to flow ____ to____
hair cells, K, K, out, in
Close to oval/round window is high or low frequency?
high
thicker part of the cochlea is high or low pitch
high
What's special about the endolymph?
high potassium low sodium
What happens when the stereocilia bend away from the kinocilium
hyperpolarization because no K+ and Ca+ come in
releasing hormone released from where
hypothalamus
is the stiff region of the cochlea near the round window or the apex? is it high or low pitch?
round window, high pitch
sound comes in at ________, high/low frequency pitch sounds.
round window, high,
sounds come out of cochlea via
scala tympani
sounds come into cochlea via
scala vestibular
cochlear hair cells are only located in the _______ media, with ______ K and ______ Na
scala, high, low
Goiter caused from which thyroidism
secondary hyperthyroidism because of overproduction of TSH or primary hypothyroidism which is not enough T3 and T4
Cretinism symptoms
short, disproportionate body, mental retardation
outer hair cells
shorten when depolarized, they increase amplitude and clarity of sound
scala media (endolymph) have extremely low concentrations of __________ and high concentrations of ___________
sodium, potassium
inner hair cell rests at ______ and endolymph rests at _______
-45, 80
an individual is perceiving two different sounds, one is 150 Hz and one is 1020 Hz. 1020 is perceived in cochlea where, 150 is perceived where
1020 is perceived at oval window, 150 perceived at apex
100 Hz or 1600 Hz sound is closer to the oval window?
1600 Hz
What is endolymph potential and perilymph potential and inner hair cell potential
80, 0, -45
organ of corti is located where?
cochlear duct/scala media
How does iodine enter the cell?
Na/I cotransporter
TSH purpose
TSH receptor activation stimulates all steps of thyroid hormone synthesis
primary nerves in ear synapse with second order where
cochlear nuclei
P blob
color
does damage to the middle ear (conductive deafness) harm all frequencies equally or specific frequencies?
all
Is amine, peptide, steroid hormone water or lipid soluble
amine is water, peptide is water, steroid is lipid
function of middle ear
amplify sound
stimulating hormone released from
anterior pituitary
inferior colliculi function
auditory reflexes
sound vibrates _______ which causes stereocilium to push against ________
basilar membrane, tectoral membrane
what changes from oval window to apex
basillar membrane thickness, not hair cells
What is Graves' disease?
body produces TSI which mimics TSH, symptoms of hyperthyroidism
organ of court located in _______ which is filled with fluid that has abnormally high ______
cochlear duct (scala media), K
when ______ enters stereocilia after the depolarization occurs, this leads to release of _______, triggers the ________ which transmits auditory information
calcium, neurotransmitter, cochlear nerve
function of the external ear
channel sound into the ear
if there's no vibration pushing the stereocilia into the tectoral membrane, gated ion channels are ______, K is/is not entering, membrane is ________
closed, is not, hyperpolarized
Anterolateral pathway sensations
coarse touch, temperature, pain
Where is endolymph located?
cochlea duct
if you have sensorineural deafness, you're damaging cells closer to the ________
cochlear base
two types of deafness
conductive deafness to middle or external ear (impairs all sound frequencies) and sensorineural which is damage to inner ear hair cells and impairs ability to hear some pitches more than others
What would happen with no middle ear
conductive deafness, can't take sound waves coming in and transmit them
superior olive is where what comes together, what is main function
convergence of both sides, sound localization
sensorineural deafness
damage to inner ear hair cells and impairs ability to hear some pitches more than others
Dorsal pathway sensations
fine touch, proprioception, vibration
cochlea is air or fluid filled?
fluid
P-interblob
form and depth
cochlear apex, low or high frequency
furthest, low frequency
if an individual has a mutation where their endolymph inside the Scala media is replaced with paralymph what happens following stereocilia bending towards kinocilia?
in paralymph, K concentration is low (mimics normal CSF/ESF), you wouldn't have extracellular K to enter, depolarization wouldn't occur when stereocilium are activated, wouldn't allow Ca to enter which means no NT released and no signal to auditory cortex
when the vibration pushes the stereocilia against the tectoral membrane into the kinocilia, gated ion channels are ______, K is/is not entering, membrane is _______
open, is, depolarized
Ending of amine hormones
ine and in
what is the primary sensory receptor of the ear
inner hair cells
frequency of action potentials increases is which type of coding
intensity coding
potassium flows _______ the hair cells because they rest at _______
into, -45
potassium flows ______ the hair cells and sodium flows ______ in the endolymph
into, out of
Enzymes add _______ to ________ to make __________ and _________
iodine, tyrosine, T3 and T4
Ending of steroid hormones
iol or one
What happens with Gs? (3)
ion channel activity via CNGs, gene transcription via CREs, phosphorylation via activation of protein kinase A
stereocilium on the hair cells which are graduated in size. largest one is ________. when they're pushed against the _______ from vibration of the basilar membrane, the stereo cilium bend towards the ________, which causes ________ gated _____ channels to open/close, ______ flows in/out hyperpolarizing/depolarizing membrane causing _______ gated _______ channels to open/close, ______ enters, and triggers vesicles to migrate towards active zone releasing _________ and activating ____________
kinocilium, tectoral membrane, kinocilium, mechanically, potassium, open, K, in, depolarizing, voltage, calcium, open, calcium, neurotransmitters, auditory neurons
Goiter is caused by excess or lack of iodine?
lack of iodine
lateral or medial superior olive is for frequencies above 3000 Hz
lateral
Is thyroxine (T3 & T4) lipid or water soluble
lipid
lipid or water soluble needs a carrier in the blood?
lipid needs a carrier
intensity coding key point
louder sound (higher amplitude) produces more action potentials
lateral superior olive function
loudness difference
Hypothyroidism (myxedema) symptoms
low BMR, feel "chilled", edema, lethargy, mental sluggishness
At the apex of the unrolled cochlea, is that high or low frequency?
low frequency
gate of ion channels in the stereocilia
mechanically gated
is lateral or medial superior olive for frequencies below 3000 Hz
medial
individual is presenting some sort of deafness. they can't hear anything - doesn't matter pitch or frequency - everything is muffled, this is damage to ______ and called _______
middle ear, conductive deafness
if you're extremely intense in the amplitude of sound waves coming iim you generate more/less action potentials
more
M pathway
movement
function of tympanic membrane
multiple muscles contract to protect middle ear and cochlea with loud sounds
Can water soluble hormones cross through the membrane
no
Do water soluble hormones need a transporter in the blood?
no
damage before superior olive is ok or no
no
do water soluble hormones need a transporter in the blood?
no
is damage of one side of the auditory cortex bad
no
When stereocilia bend away from kinocilium, lots of/no potassium enters, membrane is hyperpolarized/depolarized
no, hyper polarized
medial geniculate nucleus
part of the thalamus that filters and relays auditory information
Damage to V4 affects
perception of color
frequency and _____ are the same
pitch
frequency coding is based off of
pitch
activating hair cells is caused from shear force which opens _____ channels, when you're not hearing/no vibrations, there's no shear force so stereocilia are/are not pushing against kinocilium
potassium, are not
scala vestibuli and scala tympani (perilymph) have extremely low concentrations of __________ and high concentrations of ___________
potassium, sodium
inner hair cells
primary sensory receptors
Hypothalamus releases _______
releasing hormone
superior olive function
sound localization
______ opens potassium channels, _______ opens calcium channels
stress, voltage
once you get to _______, damage to one side won't matter so much in auditory system
superior olive
auditory cortex is tonotropic, what else is tonotropic?
the cochlea, interprets various frequencies at various locations
low frequency is sensed by thick end or thin end? near oval window or near apex?
thin, apex
Amine hormones
thyroxine (T3. T4), epinephrine, norepinephrine, dopamine, melatonin
hair cells are organized _____
tonotopically, hair cells are organized by tone
Anterior pituitary releases ________
tropic hormone
Ca channels are ________ gated in stereocilia
voltage gated
ADH function
water conservation
water or fat soluble hormones activate cAMP
water soluble
Do lipid soluble hormones need a transporter in the blood?
yes
is the auditory cortex plastic?
yes