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