TEST TWO CSD 360
manubrium
long arm of malleus
umbo
most inward part of eardrum
Sulci
valleys of brain
epitympanum
"attick" contains the bulk of the incus and malleus
Outer Hair Cell
5% of fibers are connected with these cells (CONVERGENT RELATIONSHIP)
Inner Hair Cells
95% of the fibers connect with these cells (DIVERGENT RELATIONSHIP)
Cupula
A gelatin-like structure containing a tuft of hairlike sensory receptor cells in the semicircular canals.
synapse
A junction where information is transmitted from one neuron to the next.
resting potential
At rest, the IHC it is to be at
ampulla
Cristae is located in the _________
7.9mm
Diameter of ear canal
Inferior Colliculus
EVERYONE has to stop here, visions starts coming in here
reticular lamina
Extending on top of the rods of corti is the
Myelin
Fatty substance that insulates the axon to allow for rapid transmission of info
IHC
Flask shaped, 1 row, nerve ending situated near the base of the cell
-70mV
Hair cells have an intracellular resting potential of
Saccule
Hair cells with sensitivity AWAY from the striola VERTICAL
Mastoid portion
Has greatest volume of temporal bone. Extremely pneuomatized- has no greater mass than other portion
OHC
Help with inner hair sensitivity, enhancement
Apex
High frequencies, flaccid
Tonotopically organized
High frequency- base Low frequency- apex
3-5 rows (aprox 25,000)
How any rows in OHC?
Depolarization of the cell causes a chemical to be realized in the space between the hair cell and the neuron
How does the cell firing result in the firing of the neuron?
1 row
How many rows on IHC?
2 3/4 turns
How much of the choicely is spiraled like a snail shell?
Corpus colosseum
How the two hemispheres communicate
Primary auditory cortex (A1)
I've got information. where does it go? This is where sound is processed
Vestibule (utricle and saccule)
In inner ear; linear movement
Tectorial membrane
Is attached only on one side and is raised above the basilar membrane
Base
Low frequencies, stiff
get information to the brain for processing
Main purpose of sensory system
OHC
Make up a V or W, cylinder shape, it MOVES
squamous cell epithelial, mucosal layer, fibrous layer
Name the three layers that the tympanic membrane is made of
Saccule and Utricle
Otolith Organs
Petrous Portion
Posterior face has several landmarks, most obvious being the porus acoustics
Mastoid portion
Projects inferiorly behind the external meatus, and serves as an attachment for the sternocleidomastoid muscle
Scala media and scala vestibuli
Reissners membrane separates which two cavities?
Macculea
Sensory organ for saccule an utricle
cochlea
Snail shaped structure, 35mm long, widest at base
nodes of ranvier
Space between the myelin sheath
mesotympanum
Space in the middle ear directly behind the tympanic membrane which houses the stapes is called?
Thalamus
Takes all cranial nerves and sees where they need to go
150mV
The difference between the two (or resting potential)
+80 mV
The electric potential in the scala media is approximately
+7mV
The electrical potential in the Scala tympani is
+5mV
The electrical potential in the Scala vestibule
Organ of corti
The heart of the cochlea, sits on top of the basilar membrane and is in the scala media
basilar membrane and reisnner's membrane
The two membranes in the cochlea that divide the bony labyrinth into 3 champers
Scala tympani and scala vestiboli
These two chambers point the fluid perilymph
Perilymph
Very little electric charge
OHC
WORK HORSES, movable, sound makes them dance and they make a sound in response
rods of corti
What are the supporting structures of the cochlea?
tensor tympani
What muscle of the middle ear is innervated by the mandibular division of CN V?
tunnel of corti
What structures give the cochlea its rigidity
Cupula
When bent there is MORE firing
stapes
Which ossicle of the middle ear covers the oval window?
Because is houses the cochlea, VERY hard, cochlea is HIGHLY protected
Why is the temporal bone important?
Associative auditory cortex (A11)
You understand/comprhened sound Has a lot to do with auditory memory
tensor tympanic
_________ muscle inserts into the malleus and is innervated by the mandibular division of trigeminal nerve CN3. Decreases vibration
Action Potential
a bunch of neurons firing at the same time
middle ear
a cavity in bone containing the ossicle
inner ear
a cavity in the temporal bone, it is filled with fluid
Nerve
a group of neurons
incudostapedial joint
a rather fragile ball and socket arrangement
Receptor Potential
a release of neurotransmitter from the hair cell to the afferent auditory nerve
middle ear
a series of spaces and structures, it transmits the airborne sound of the outer ear to the fluids that fill the inner ear
hypotympanum
a shallow space that lies inferior to the tympanic membrane. bony surface that looks scalloped due to cup like air cells. this wall covers jugular bulb
tympanic membrane
a slightly cone shaped structure separating the outer and middle ear
Heschl's gyrus
another name for primary auditory cortex
malleus and incus
are bound firmly together and tend to move as a unit
positive/negative
at resting potential, endolypmh is ________ which the IHC is ___________
polarized
at resting the IHC is in a _______ state
tensor tympani
attached to the malleus near the TM
vestibular system
balance sensing organs
middle ear
begins with tympanic membrane
pneuomatized
bone has lots of little openings
mucosal layer
bounding the middle ear laterally
mucosal layer
bounding the middle ear laterally, close to inside
gyri
bumps/ridges
buckling vibratory action
causes an addition multiplication by 2. thus you get a theoretical maximum total pressure increase
the outer ear
causes an increase in the level of about 10-15 dB in a frequency range from about 1.5-7kH
Petrous Portion
cochlea is housed here
pinnas
come in carrying sizes,they funnel sound increasing the energy
fibrous layer
composed of both circumferential and radial fibers to give the membrane its shape and consistency
eustachian tube
connects to the back of the throat and opens periodically to allow fresh air in
external ear
consists of the auricle and the external auditory canal
Inner hair cells
contains 95% of afferent fiber
retrocochlear pathways
convey information to the brainstem and brain
1-2cm
diameter of outer ear
cerumen
earwax, helps keep skin from drying out
pars tensa
elastic part of the membrane that is primarily responsible for sound transmission
stenois
excessive narrowing of the osseocartiligenous junction
reticular lamina
extending on top of the rods of court is the
5-9mm
external auditory canal diameter
2-3 cm
external auditory canal length
external auditory canal
first 1/3 of the canal is cartilage with glands and lined with hair next 2/3 is tight skin over bone until eardrum or tympanic membrane
temporal bones
form the sidewalls of the skull
tympanic portion
forms the floor and part of the walls of the ear canal
Perilymph
found in scala vestibule and scala tympani
eustachian tube
fresh air comes in thru this tube, is connected to a place in the back of the throat
middle ear
functions include overcoming the impedance mismatch
superior olivary complex
gets information from BOTH ears
cochlear nucleus
gets information from ears HAS to stop here
circumferential fibers (of tympanic membrane)
give strength without interfering with free vibration
Afferent ribers
goes up to brain
Endolymph
has a LOT of potassium and a positive charge
temporal bone
has five parts: Squama, mastoid, petrous, tympanic and styloid
outter ear
helps localization, timing, intensity
temporal bone
houses part of the external ear as well as all of the middle and inner ear
Action potential
if you get a lot of shearing motion then you have a great charge which in turn can be detected as a
bony spiral lamina
in the scala media the ___________ sports the limbus (thickened layer of periosteum)
Efferent
information travels from the brain to a specified site
tensor tympani tendon
inserts on the medial surface of the upper end of the manubrium, goes to malleus
radial fibers (of tympanic membrane)
insets into the periosteum of the malleus handle and into the fibrous annulus creating the functionally significant conical shape
Porus acoustic
internal auditory canal (AUDITORY NERVE RUNS THRU HERE)
Organ of corti
is a gelatinous and fibers flap. The outer hair cells are embedded in the tectorial membrane whereas the inner hair cells are not.
external auditory canal
is bounded medially by the tympanic membrane, the skin covering the cartilaginous portion of the canal is loosely applied and contains numerous hair follicles and cerumenous
tensor tympani
is connected to the upper part of manubrium of the malleus by a tendon
External auditory canal
is formed in its outer 1/3 by an extension of the cartilage of the auricle and in its inner 2/3 by the tympanic and squamous portion of the temporal bone
concha
is the bowl closest to the external meatus
antihelix
is the cartilage ride
epitympanum
is the celling of tympanum
promontory
is the medial wall (bulldogs out) of tympanum
manubrium
it is flat and rounded inferiorly, ending at the jumbo of the tympanic membrane
middle ear
its a cavity, space between the tympanic membrane and the capsule of the inner ear, the ossicular and muscular contents of this space and the appendages
pars tensa
largest portion of tympanic membrane, it is the stiffest and contains all three layers
squamous cell epithelial
layer bounding the external ear medially
fibrous layer
lies in between, composed of both circumferential and radial fibers to give the membrane its shape and consistency
malleus
long arm attached to the TM and pulls inward tip of manubrium called the umbo
reflex threshold
lowest level of stimulus intensity that will trigger a reflex
acoustic reflex
main function is to protect the cochlea from high sound energies that would damage inner ear
Otolith Organs
means there are rocks in your ear
stapedial muscles and tensor tympanic
middle ear muscles
stapedius
muscle contracts: causes it to vibrate as well
First order neurons
neurons that hit cochlea nucleus first
serous
non-infected fluid
bone conduction
occurs as the eardrum vibrates and moves the auditory ossicles
leveling action of malleus and incus
one of the ways in which the ear overcomes the sound loss that will occur as energy enters the cochlear fluid
eustachian tube
opens and closes to equalize pressure between middle ear and environment
cochlea
organ for hearing
outer ear
pinna and external auditory canal. primarily cartilage with numerous bumps and groove
tonotopic organization
places most sensitive to frequencies are not evenly space, high frequencies are more closely spaced than low frequencies
mastoid portion
posterior to the external auditory meatus and middle ear has small air-filled cavities
parietal
primary somatosensory cortex
reticular lamina
provides a barrier which prevents endolyphm of SM from entering interceullar spaces around the hair cell, electrical resistance
eustachian tube
provides an exit for mucus or other material that is in middle ear
Lateral Lemniscus
really more of a track, not a structure it is the primary auditory pathway
dendrites
receive information from other neurons of sensory sells
superior olivary complex
receives inform from BOTH ears IMPORTANT FOR LOCATION do NOT have to stop here
plasticity
refers to changes in the anatomy and physiology of neural structures that occur after these structure receive neural inputs that differ from those that have previously been received
Medial Geniculate Body
relay system
4.5-5kHz
resonant peak of concha
2.5kHz
resonant peak of external auditory canal
eustachian tube
rest on the floor of of the tympanum
Stereocelia
rigid and composed of actin and myosin, both OHC and IHC have these projecting from the top
endolymph
scala media only
cartilaginous portion
section of the canal passing thru the soft tissue and cartilage
axon
send info away from the cell body
tympanic membrane
separates the outter and middle ear
stapes
shaped like a stirrup, fits into oval window
Habenula perforata
small opening from the models to scala media
pars flaccid
smaller area of TM does not contain fibrous layer and is more superior and medial
stapedial muscle
smallest muscle in the body, attaches to the neck of stapes
thru the bone, middle ear cavity, or by ossicular chain
sound can be transmitted thru the middle ear by three ways
area difference in TM and oval window
sound funneled into a smaller area
foramen magnum
spinal chord goes thru here
Basil membrane
stiff and narrow at the base and floppy at appex
IHC
stimulated by fluid pressure movement and movement of the basilar membrane
infected fluid
suppurative
osceotympanic membrane
the bone conducts sound becomes air conducted and some of it will travel via the normal route to the middle ear
reticular lamina
the celia of the outer hair cells project to the tecotiral membrane, also provide a barrier which prevents endolymph of SM from entering intercellular spaces around the hair cell
scala media
the middle chamber of the cochlea which is filled with the fluid endolymph
area difference in TM and oval window leveler action of ossicular chain Shape of TM and buckling factor
the middle ear helps transfer the power in three ways
osseocartilagionous junction
the narrowest part of the ear canal,its here that the cartillage portion ends and a bony portion begins
aditus
the opening that connects the middle ear with the mastoid air spaces
Basil Membrane
the organ of corti sits on top of the
tectorial membrane
the outer hair cells are embedded in the _______________ whereas the inner hair cells are not
BASE of the basil membrane
the peak of high frequencies will occur at the _________
air conduction
the process by which sound waves enter the ear through the pinna
pars flaccid
the segment of TM superior to the miller folds is completely lacking a fibrous layer
cristae
the sensory organ of rotation located in the semicircular canal of the inner ear
pinna
the skin covered, cartilaginous flap that is also called the auricle
Synaptic cleft
the space between the two neurons
modiolus
the spiral structure of the cochlea consisting of nerve and blood vessels
tectorial membrane
the upper edge of the limbus provides he point of attachment for the ________ this extends out into the scala media
petrous portion
thickened, extremely hard, forms part of the floor of the cranial cavity and surrounds the inner ear
Squamous Portion
thin and convex, outward. It is external surface has attachment to the temporals muscle
squamous portion
thin, fanlike superior portion of the temporal bone of cradles and protect the temporal lobe of the brain
reticular lamina
tonic barrier until its time to fire
1.3cc
volume of external auditory canal
traveling wave
wave motion on the oval window, which displaces the scala media perpendicularly; is transverse
protect, reduce self-producesd sounds, frequency response smoothing, may help with upward spreak of masking by attenuating low frequencies
what do middle ear muscles do?
Second order neurons
when neurons on on their way to the superior olivary complex
Midbrain
where is the inferior colliculus located
pons
where is the lateral lemniscus located
3,500
# of IHC
occlusion effect
-Increase in loudness when the ears are occluded during bone conduction
round
Because the_________ is membranous, fluid can be displaced
3.5 cm/1.5 cm
Ear canal length
Utricle
HORIZONTAL Hair cells oriented with sensitivity TOWARDS striola
Simicircular canals
Inner ear; angular movements
Cortex
Personality, you
Afferent
Sensory info is sent to the brain for processing
+80 mV
The EP in a normal resing cochlea is about
Scala media and scale tympani
The basil membrane separates which two cavities?
-40 to -70 mV
The cochlear hair cells have a resting electrical potential of
Occipital
Vision
tunnel of corti
Where do the rods of corti come together?
Thalamus
Where is the Medial Geniculate Body located
Medulla
Where is the cochlear nucleus located?
Pons
Where is the superior olivary complex located?
OHC
actively pull down on the tectorial membrane, enhancing the traveling wave
Refractory period
after a hair cell fires, it goes thru what is called It has to go back to being polarized
IHC
associated with afferent fibers of auditory nerve
squamous cell epithelial
bounds the external ear medially, close to outside
incus
has a body that narrows to form the short process of middle ear
Temporal
hearing
Frontal lobe
higher level thought, personality, primary motor
Tympanic portion
incomplete cylinder with aqua superiorly forms the bony external auditory canal (meatus)
Organ of corti
is a gelatinous and fibrous flap
neuron
is a nerve cell
middle ear
is said to be an impedance-matching transforming device because sound is going from acoustic to fluid
