AUD 511 EXAM WITH CORRECT
SOLUTION
Temporal Bone - ANSWER houses the inner ear (IE) in a labyrinth foramen deep inside
hardest and most complex bone in the skull
Sqamous - ANSWER Temporal bone:
-flat or fan like
-projects superiorly from petrous
-part of lateral wall of ME
Base - ANSWER Basilar membrane
-narrow
-stiff
-high frequencies
Apex - ANSWER Basilar membrane
-thick
-less stiff
-low frequency
Basilar membrane - ANSWER has an apex and base
3 layers
1. connective tissue (outer layer)
2. Transverse fibers (middle)
3. Homogenous substance (same material)
Stria Vascularis - ANSWER blood flow to cochlea?
Reissner Membrane - ANSWER What separates the scala vestibuli and the scala media?
basilar membrane - ANSWER What divides the scala tympani and the scala media?
,Ductus Reuniens - ANSWER Where does the cochlea and vestibule meet?
Saccule - ANSWER what is closes to the auditory/cochlear portion?
Endolymphatic Sac - ANSWER What helps maintain volume and quality of endolymph
fluid?
The ampulla - ANSWER the hair cells are found where?
Function of the Inner Ear - ANSWER converts mechanical stimuli (sound waves and fluid
displacement) to neural impulses that can be recognized by the brain for HEARING and
BALANCE
Petrous Portion - ANSWER Temporal bone
-very thick, and rugged portion
-very hard
-cavity of the middle ear
bony and membranous - ANSWER The inner ear is made up of 2 labyrinths
1.
2.
1. vestibule (balance)
2. cochlea (hearing) - ANSWER The inner ear has 2 distinct sensory organs
1.
2.
At birth - ANSWER the vestibule and cochlea are fully developed when?
Morphological and Physiological - ANSWER Both the cochlea and vestibule share
__________ and __________ properties
such as:
-hair cells
-mechano-transduction mechanism
-fluid (endolymph)
shape and function - ANSWER Morphological is the __________ where physiological is the
___________
,perilymph - ANSWER -type of fluid
-30 times more fluid than the endolymph
-similar to extra-cellular fluids (blood)
-toxic hair cells
-high sodium, low potassium
-Fills scala tympani, scala vestibuli
-78.3mm^3 volume
Endolymph - ANSWER -type of fluid
-similar to intra-cellular fluids
-poor environment for hair cells
-high in potassium, low in sodium
-fills scala media
-2.76mm^3 volume
cortilymph - ANSWER -type of fluid
-fills tunnel of corti
-beneath reticular lamina
-created by blood vessels beneath basilar membrane
-higher in sodium than the endolymph
-not toxic to hair cells
1. deliver nutrients and remove wast from inner hair cells
2. prove chemical environment needed for transduction
3. medium to carry vibrations from footplate to the sensory structures along the
cochlear partition
4. controls distribution of pressure in the inner ear system (?) - ANSWER What's the
point of fluid
false - ANSWER True or False
fluids in the inner ear are secreted and resorbed in volume?
True,
, they do not flow, the are static (stay put) - ANSWER True or False
endolymph and perilymph do not flow along their respective compartments in the
cochlea
Ion Transport Processes - ANSWER maintenance of chemical composition of both fluids
is dominated by _________________ which are localized in each region
-the ability to transport ions (+,-)
Cochlea - ANSWER -spiral structure
-2 3/4 turns
-unwound is 1nch in length
-0.5cm in height when a spiral(compact)
-spirals from saccule
-responsible for converting sounds from mechanical vibrations to electrical signals
(transduction)
Transduction - ANSWER -performed by specialized sensory cells within the cochlea that
convert vibration to electrical signals and code the sounds
-the electrical signals carry the
code to the brain via the
vestibcochlear nerve
cochlea - ANSWER -looks like a snail shell
-spirals around a bony column called the modiolus
-3 canals within
1. scala vestibuli
2. scala media
3. scala tympani
Modiolus - ANSWER pillar that the cochlea runs up (coils around)
1. scala vestibuli
2. scala media
3. scala tympani - ANSWER What are the 3 canals of the cochlea
Scala media - ANSWER The organ of corti is found in the ....
SOLUTION
Temporal Bone - ANSWER houses the inner ear (IE) in a labyrinth foramen deep inside
hardest and most complex bone in the skull
Sqamous - ANSWER Temporal bone:
-flat or fan like
-projects superiorly from petrous
-part of lateral wall of ME
Base - ANSWER Basilar membrane
-narrow
-stiff
-high frequencies
Apex - ANSWER Basilar membrane
-thick
-less stiff
-low frequency
Basilar membrane - ANSWER has an apex and base
3 layers
1. connective tissue (outer layer)
2. Transverse fibers (middle)
3. Homogenous substance (same material)
Stria Vascularis - ANSWER blood flow to cochlea?
Reissner Membrane - ANSWER What separates the scala vestibuli and the scala media?
basilar membrane - ANSWER What divides the scala tympani and the scala media?
,Ductus Reuniens - ANSWER Where does the cochlea and vestibule meet?
Saccule - ANSWER what is closes to the auditory/cochlear portion?
Endolymphatic Sac - ANSWER What helps maintain volume and quality of endolymph
fluid?
The ampulla - ANSWER the hair cells are found where?
Function of the Inner Ear - ANSWER converts mechanical stimuli (sound waves and fluid
displacement) to neural impulses that can be recognized by the brain for HEARING and
BALANCE
Petrous Portion - ANSWER Temporal bone
-very thick, and rugged portion
-very hard
-cavity of the middle ear
bony and membranous - ANSWER The inner ear is made up of 2 labyrinths
1.
2.
1. vestibule (balance)
2. cochlea (hearing) - ANSWER The inner ear has 2 distinct sensory organs
1.
2.
At birth - ANSWER the vestibule and cochlea are fully developed when?
Morphological and Physiological - ANSWER Both the cochlea and vestibule share
__________ and __________ properties
such as:
-hair cells
-mechano-transduction mechanism
-fluid (endolymph)
shape and function - ANSWER Morphological is the __________ where physiological is the
___________
,perilymph - ANSWER -type of fluid
-30 times more fluid than the endolymph
-similar to extra-cellular fluids (blood)
-toxic hair cells
-high sodium, low potassium
-Fills scala tympani, scala vestibuli
-78.3mm^3 volume
Endolymph - ANSWER -type of fluid
-similar to intra-cellular fluids
-poor environment for hair cells
-high in potassium, low in sodium
-fills scala media
-2.76mm^3 volume
cortilymph - ANSWER -type of fluid
-fills tunnel of corti
-beneath reticular lamina
-created by blood vessels beneath basilar membrane
-higher in sodium than the endolymph
-not toxic to hair cells
1. deliver nutrients and remove wast from inner hair cells
2. prove chemical environment needed for transduction
3. medium to carry vibrations from footplate to the sensory structures along the
cochlear partition
4. controls distribution of pressure in the inner ear system (?) - ANSWER What's the
point of fluid
false - ANSWER True or False
fluids in the inner ear are secreted and resorbed in volume?
True,
, they do not flow, the are static (stay put) - ANSWER True or False
endolymph and perilymph do not flow along their respective compartments in the
cochlea
Ion Transport Processes - ANSWER maintenance of chemical composition of both fluids
is dominated by _________________ which are localized in each region
-the ability to transport ions (+,-)
Cochlea - ANSWER -spiral structure
-2 3/4 turns
-unwound is 1nch in length
-0.5cm in height when a spiral(compact)
-spirals from saccule
-responsible for converting sounds from mechanical vibrations to electrical signals
(transduction)
Transduction - ANSWER -performed by specialized sensory cells within the cochlea that
convert vibration to electrical signals and code the sounds
-the electrical signals carry the
code to the brain via the
vestibcochlear nerve
cochlea - ANSWER -looks like a snail shell
-spirals around a bony column called the modiolus
-3 canals within
1. scala vestibuli
2. scala media
3. scala tympani
Modiolus - ANSWER pillar that the cochlea runs up (coils around)
1. scala vestibuli
2. scala media
3. scala tympani - ANSWER What are the 3 canals of the cochlea
Scala media - ANSWER The organ of corti is found in the ....
