Neuro- ear anatomy & auditory system Flashcards
what are the structures of the external ear?
1) Pinna
2) external auditory canal
3) tympanic membrane
the middle ear consists of the Tympanic membrane, and the middle ear cavity which holds the ______
ossicles
name the ossicles
Malleus
incus
stapes
the tensor tympani muscle attaches to which ossicle?
Malleus
what nerve innervates the tensor tympani muscle?
CN 5 (trigeminal)
which muscle attaches to the stapes?
stapedius muscle
the stapedius muscle is innervated by what?
CN 7 (facial nerve)
the inner ear consists of 2 ______
labyrinths
which inner ear labyrinth is located in the temporal bone?
osseous labyrinth
the membranous labyrinth contains ___________ of the ear
neuroepithelium
the cochlear duct and organ of corti are located where?
in the membranous labyrinth
the vestibular labyrinth is involved with sensing ______
balance
the osseous labyrinth is found in the ______ portion of the temporal bone
petrous
the osseous labyrinth is filled with what fluid?
perilymph
the membranous labyrinth consists of ducts and chambers filled with ______
endolymph
the membranous labyrinth contains the sensory ______ of the inner ear
neuroepithelium
the membranous portion of the cochlear division of the inner ear consists of the ____ ____
scala media
what is another name for the scala media?
cochlear duct
what are the 3 ducts of the cochlea?
1) Scala media (cochlear duct)
2) Scala tympani
3) Scala vestibuli
the scala media is part of the _______ labyrinth
membranous
the scala vestibule is part of the ______ labyrinth
osseous (bony) labyrinth
the Footplate of the stapes is the ________
oval window
the scala ____ is filled with endolymph
scala media
which structures are filled with perilymph?
1) Scala Vestibuli
2) Scala Tympani
the auditory duct starts at the oval window and ends at the ______ window
round
the organ of corti is also known as what?
the spiral organ
what separates the scala vestibuli from the scala media?
Vestibular (reissner’s) membrane
the scala media is bounded by the vestibular and basilar membranes. this cavity is filled with ______
endolymph
where is the organ of corti found?
inside the scala media
what structure lies directly above the hair cells in the organ of corti?
tectorial membrane
hair cells of the organ of corti are in contact with ___________ nerves
statoacoustic nerves
which cranial nerve projects statoacoustic nerves into the organ of corti?
CN 8
the basilar membrane separates which 2 cochlear chambers?
scala tympani from the scala scala media
what are the 2 auditory streams
the “what” and the “where”
the “what” auditory stream is involved with what form of processing?
language processing
which cochlear nucleus is involved with the “what” auditory system?
dorsal cochlear nucleus
the “where” auditory stream is involved with what aspect of sound stimuli
location of sound
the “where” auditory stream is involved with which cochlear nucleus?
ventral cochlear nucleus
which nuclei are involved with the flow of information from the ventral cochlear nucleus?
1) superior olivary nucleus
2) nucleus of the lateral lemniscus
most of the output neurons from the ventral cochlear nucleus project to where?
superior olivary nucleus
the superior olivary complex is involved with sound ______
location
what factors allow the superior olivary complex to detect sound location?
1) time delay between ears
2) intensity differences of sound
the superior olivary complex uses the ________ system
olivocochlear system
what is the termination of the olivocochlear system?
outer hair cells of cochlea
the olivocochlear system’s function is to:
A) protect from loud sounds
B) suppress constant background noise
plays a role in postnatal hearing development
from the spiral ganglion and statoacoustic nerves (of CN 8), the nerves travel where?
to the cochlear nuclei
what type of nerve fibers exit the cochlear nuclei?
crossing, second order, auditory fibers
fibers from the cochlear nuclei ascend ______ and ______
ipsilateral and contralateral
fibers of the cochlear nuclei travel through the __________ to reach the inferior colliculus
Lateral lemniscus
after passing through the lateral lemniscus, where do nerve fibers terminate?
the inferior colliculus
nerve fibers from the inferior colliculus travel where?
A) medial geniculate body
then to the primary auditory cortex
Where is the medial geniculate body found?
the thalamus
the “what” auditory stream projects from the primary temporal gyrus in a ventral direction to where?
superior and middle temporal gyri
language processing
the “where” auditory stream projects dorsally to what part of the cortex?
superior parietal lobule
**plans motor response to stimuli location
nerve fibers traveling from the inferior colliculus to the superior colliculus are responsible for what? which auditory stream are they from?
from the “where” auditory stream
give reflex response to sound stimuli
what areas of the temporal lobe are involved with “what” auditory processing?
superior & middle temporal gyrus
what specific gyrus contains the primary auditory gyrus?
Helschl’s gyrus
Brodmann’s area 41
where in the cortex does word processing occur?
Anterior Superior temporal gyrus
where does sentence processing occur in the cortex?
Posterior Superior temporal gyrus
which gyrus of the cortex is responsible for planning motor function based on sound?
superior parietal lobule
which structure is responsible for generating reflexes based on sound?
superior colliculus
the superior olivary complex is responsible for what 2 functions?
1) sound location
2) olivocochlear system (protect ear from loud noises)
