AUD 612 - Final Exam (AN) Study Set
Auditory Nerve (AN) - ANSWER connection between cochlea and brainstem, onto brain
break down the incoming acoustic signal into its components.
to relay accurately all information to the CANs for further processing and extraction of
relevant, perceptually salient components. - ANSWER Role of the AN is to
afferent & efferent - ANSWER the auditory nerve contains about 30,000 fibers composed
of both ______ & ______ fibes
peripheral - ANSWER the AN has a _________ connection to hair cells in the cochlea
counter-clockwise - ANSWER The AN passes through the IAM
AN Twists _______ as it leaves cochlea through IAM
Straight path - ANSWER The AN has a relatively ________ as it travels toward the
brainstem
clock-wise - ANSWER AN twists ________ as it approaches the brainstem
faster - ANSWER larger fibers have ______ neural conduction speeds
neural conduction speeds - ANSWER Nerves with myelin have faster
central - ANSWER More dense distribution of auditory nerve fibers in _______ region of
cochlea/basilar membrane
Base & Apex - ANSWER 400 fibers/mm
3-4 fibers per IHC
Middle of cochlea - ANSWER 1400 fibers/mm
15 fibers per IHC
Type I Fibers - ANSWER 90-95 % of AN fibers
Mostly innervated by IHCs
Larger; more myelination
radial - ANSWER Type I fibers are described as _________ fibers
Type II Fibers - ANSWER 5-10% of AN fibers
mostly innervate OHCs
, Each AN fiber innervates multiple OHCs
run longitudinally to connect with multiple OHCs.
spiral or longitudinal - ANSWER Type II fibers are described as ______fibers
habenula perforata - ANSWER AN fibers are unmyelinated in region between hair cells
and ____________
IAM
Schwann Cells - ANSWER Most fibers become myelinated as they pass through the
_______.
Cerebellopontine Angle (CPA) - ANSWER After leaving the IAM, fibers pass through
recess, the __________
Oligondendrocyte Myelin - ANSWER As AN fibers approach brainstem, myelination type
changes to _______
pontomedullary junction - ANSWER The AN fibers enter the brainstem at the lateral,
posterior _________
ventral cochlear nuclei (VCN) - ANSWER the pontomedullary junction is the input area
between the dorsal and posterior _____________
tonotopically - ANSWER AN fibers are ___________ organized
apical end of the cochlea - ANSWER Low-frequency AN fibers connect to HCs at
basal end of cochlea - ANSWER High-frequency AN fibers connect to HCs at
High frequency AN fibers are wrapped around the outside of nerve bundle - ANSWER
Damage to the outside of the AN would result in a high-frequency HL because
low frequency fibers are located at the center/core of the nerve - ANSWER Damage to
the core of AN would result in a low-frequency loss because
longer - ANSWER LF fibers are slightly _______ than HF. So there route to the brainstem
is longer than for HF fibers
IAM - ANSWER Arrangement of HF & LF fibers maintained through the
conduction velocity - ANSWER velocity of impulses traveling along AN
the amount of myelin covering axon of nerve fiber. - ANSWER conduction velocity is
related to
more myelin - ANSWER Longer diameter of nerve fiber =
Glutamate & Aspartate - ANSWER Key neurotransmitters of AN
Auditory Nerve (AN) - ANSWER connection between cochlea and brainstem, onto brain
break down the incoming acoustic signal into its components.
to relay accurately all information to the CANs for further processing and extraction of
relevant, perceptually salient components. - ANSWER Role of the AN is to
afferent & efferent - ANSWER the auditory nerve contains about 30,000 fibers composed
of both ______ & ______ fibes
peripheral - ANSWER the AN has a _________ connection to hair cells in the cochlea
counter-clockwise - ANSWER The AN passes through the IAM
AN Twists _______ as it leaves cochlea through IAM
Straight path - ANSWER The AN has a relatively ________ as it travels toward the
brainstem
clock-wise - ANSWER AN twists ________ as it approaches the brainstem
faster - ANSWER larger fibers have ______ neural conduction speeds
neural conduction speeds - ANSWER Nerves with myelin have faster
central - ANSWER More dense distribution of auditory nerve fibers in _______ region of
cochlea/basilar membrane
Base & Apex - ANSWER 400 fibers/mm
3-4 fibers per IHC
Middle of cochlea - ANSWER 1400 fibers/mm
15 fibers per IHC
Type I Fibers - ANSWER 90-95 % of AN fibers
Mostly innervated by IHCs
Larger; more myelination
radial - ANSWER Type I fibers are described as _________ fibers
Type II Fibers - ANSWER 5-10% of AN fibers
mostly innervate OHCs
, Each AN fiber innervates multiple OHCs
run longitudinally to connect with multiple OHCs.
spiral or longitudinal - ANSWER Type II fibers are described as ______fibers
habenula perforata - ANSWER AN fibers are unmyelinated in region between hair cells
and ____________
IAM
Schwann Cells - ANSWER Most fibers become myelinated as they pass through the
_______.
Cerebellopontine Angle (CPA) - ANSWER After leaving the IAM, fibers pass through
recess, the __________
Oligondendrocyte Myelin - ANSWER As AN fibers approach brainstem, myelination type
changes to _______
pontomedullary junction - ANSWER The AN fibers enter the brainstem at the lateral,
posterior _________
ventral cochlear nuclei (VCN) - ANSWER the pontomedullary junction is the input area
between the dorsal and posterior _____________
tonotopically - ANSWER AN fibers are ___________ organized
apical end of the cochlea - ANSWER Low-frequency AN fibers connect to HCs at
basal end of cochlea - ANSWER High-frequency AN fibers connect to HCs at
High frequency AN fibers are wrapped around the outside of nerve bundle - ANSWER
Damage to the outside of the AN would result in a high-frequency HL because
low frequency fibers are located at the center/core of the nerve - ANSWER Damage to
the core of AN would result in a low-frequency loss because
longer - ANSWER LF fibers are slightly _______ than HF. So there route to the brainstem
is longer than for HF fibers
IAM - ANSWER Arrangement of HF & LF fibers maintained through the
conduction velocity - ANSWER velocity of impulses traveling along AN
the amount of myelin covering axon of nerve fiber. - ANSWER conduction velocity is
related to
more myelin - ANSWER Longer diameter of nerve fiber =
Glutamate & Aspartate - ANSWER Key neurotransmitters of AN
