A & P Ear Lab
The higher the waves......
the higher the waves → the greater the decibels are → the louder the sound
How does the middle ear transfer vibrations?
the malleus is attached to the tympanic membrane → transfers vibrations to the incus → transfers to the stapes → transfers to the oval window
What is the structure inside the cochlear duct called?
rogan of corti
What type of movements are the semicircular canals particular sensitive to?
rotational movements
What is the smaller membranous sac the responds to vertical head movements called?
saccule
When can our sense of balance be tricked?
- when our visual sense is contradicted by other senses
What is nerve deafness?
some sort of issue w/ cochlea or cochlear nerves
What are the hairs called?
stereo cilia & kinocilia
What is responsible for detecting sound? Describe its structure.
cochlea → made up of three tubes curled → is actually the same duct
What is the otolith?
combination of statoconia & gelatinous material
What are sound waves?
compressions & decompressions of the molecules that make up the air
What can ear plugs cause?
conduction deafness
Which direction is the cupula going to swing if we are swinging clockwise?
counter clockwise
What is the raised floor of hair cells celled?
crista
How is movement detected?
cupula moves back and forth w/ movement which bends/pulls the cilia
What is the number of compressed regions that pass a given point in one second called? What does this describe?
frequency → pitch of the sound
What does the auditory tube (eustachian tube) do? How?
function is to equalize pressure on both sides of the tympanic membrane → leads to the nasopharynx → leads to nasal cavity and oral cavity → open to atmosphere → swallowing air equalizes air pressure
How are the hair structures of the Organ of Corti different from the hair structures in the vestibules and semicircular canals?
hair cells in Organ of Corti are not embedded in or touching the gel
What are the units for frequency?
hertz Hz c per second → cycles per second v per second → vibrations per second
What does the Weber's and Rinne test determine?
if you have deafness & what kind (conduction deafness or nerve deafness)
What is the theory behind the sobriety tests?
in a depressed nervous system, concentration may result in a loss of balance → testing cognitive behavior associated w/ a balance response → brain can process both tasks at the same time if not compromised
What does walking a straight line well indicate?
indicates normal function of the equilibrium apparatus
Why is it important to have equal pressure on both sides of the tympanic membrane?
it is fragile and thin → if a stronger pressure on one side will burst
Why is the periphery vision so important?
it is good at picking up movements to the side → can then turn you head to focus the image on the center of the retina
What semicircular duct is activated when one is sitting in a chair spinning around?
lateral semicircular canal
What are we stimulating when we spin (clockwise) around in the chair? How?
lateral semicircular canal → fluid in canal is going to move counter-clockwise direction
How are the semicircular canals arranged?
length, width, breath - can be stimulated al at once
Was there more or less sway when we were standing w/ eyes open? Why?
less sway w/ eyes open → more sensory input to the brain
What structure is found in both sacs called?
macula
What is the inner fluid filled tube called? fluid?
membranous labyrinth endolymph
What is the coclear duct comprised of? Position?
membranous labyrinth filled w/ endolymph - b/t the tympanic & vestibular duct
How does the vestibules work?
movement causes otolith to life across the surface of the macula → causes cilia to bend→ creating a signal
What does the brain monitor when it is monitoring proprioception?
muscle tension muscle length joint position
Can nerve deafness be corrected?
not as well as conduction deafness
What is the reflex of the eyes that occurs in attempt to maintain balance called?
nystagmus
What do we use to figure out the world around us?
our senses
How does the ear detect directional sense?Difficult?
- able to determine by analyzing the delay of sound b/t the ears - difficult to do when the sound is far away
What is static equilibrium? Exception? What part of the inner ear monitors for it?
- equilibrium that is maintained when the body is at rest - exception → slight head movements "yes & no" - vestibule
What is dynamic equilibrium? What part of the body monitors it?
- equilibrium that is maintained when the body is in motion - semicircular canals
Describe the steps that are involved for us to hear something.
1. Sound waves are funneled into the external acoustic canal via the auricle 2. the tympanic membrane turns the sound waves into mechanical waves 3. the auditory ossicles transfer the vibration to the inner ear (tympanic membrane → malleus → incus → stapes) 4. the stapes (stirrup w/ a foot plate on the end) hits the oval window 5. pressure waves travel through the vestibular duct and the tympanic duct causing the basilar membrane in the organ of corti to raise up 6. hair cells will touch/bend when they hit the tectorial membrane → causing the signal to go to the brain
What is the function of the auricle?
1. acts as a funnel for sound waves 2. picks up directional sense
What are the parts of the middle ear?
1. auditory ossicles → malleus → incus → stapes 2. auditory tube, eustachian tube, pharyngotympanic tube
What three parts make up the external ear?
1. auricle 2. external acoustic meatus (canal) 3. tympanic membrane (ear drum)
What three structures make up the organ of Corti?
1. basilar membrane 2. raised floor of cells 3. tectorial membrane
What are the three parts of the ear?
1. external ear 2. middle ear 3. inner ear
What does the macula contain?
1. floor of supporting cells 2. stereo cilia & kinocilia 3. otolith
What three things does the inner ear respond to?
1. hearing 2. static equilibrium 3. Dynamic equilibrium
What two factors are important to consider in conduction deafness?
1. loudness 2. exposure time
What are the three main components of the semicircular canals? Made of?
1. semicircular canal → bony labyrinth 2. semicircular ducts → membranous labyrinth 3. ampulla →
What three structures make up the inner ear?
1. semicircular canals 2. vestibules 3. cochlea
List the three main structures of the cochlea.
1. tympanic duct 2. vestibular duct 3. cochlear duct
What test involved the spinning chair? Trying to stimulate?
Barany Test stimulate: nystagmus & vertigo
What is the floor/roof of the Organ of Corti called?
Basilar membrane - floor Tectorial membrane - roof
What was the conclusion of the picking 3 coins up experiment?
Needed : vision balance (vestibules & semicircular canals) proproception → information going to the cerebellum → multi forms of stimuli entering the brain
When does vertigo occur?
Occurs when the CNS receives conflicting sensory info from the inner ear, eyes and other receptors
What test involved placing the tuning forks behind the ear?
Rinne Hearing test
What test were we preforming when the patient was standing on one leg w/ eyes open/closed?
Romberg test
What happens in a cernterfuge?
Under high G forces the blood vessels are compressed and blood is reduced - no blood → no O2 → no vision returns when G force is decreased b/c blood vessels are able to provided O2 to eye
What test involved placing tuning forks on top of your head?
Webers Test
Where did we place the tuning fork behind the ear? Why
against the mastoid process → wanted to test for bone conduction
Which conduction works the best?
air conduction is the better form of conduction
What describes how how the sound waves are? Describes?
amplitude → loudness of a sound
List the auditory ossicles? What do they do?
auditory ossicles → malleus, incus, stapes 1. transfer vibrations from the external ear to the inner ear 2. amply vibrations
Movements of the fluid in the semicircular canals reflect what?
body movements
What two conductions were we testing for?
bone conduction air conduction
What is the outer fluid filled tube called? Fluid?
bony labyrinth perilympth
What is the tympanic duct comprised of?
bony labyrinth tube filled w/ perilymph
What is the vestibular duct comprised of?
bony labyrinth tube filled w/ perilymph
How does nystagmus work?
brain is receiving signals and moves the eyes forward and then trails back trying to anticipate moving → looking for a stationary object to focus on
What is the statoconia?
calcium carbonate crystals
What is a reduction in the sense of hearing called? Two kinds?
deafness 1. conduction deafness 2. nerve deafness
What is the units for amplitude?
decibel → dB
What is the brain trying to do when it conducts the nystagmus reflex?
pupils ar jumping forward and trailing trying to find a stationary object → trying to maintain balance
Why was there more swaying w/ eyes closed? Why is this similar to the slight simulator?
don't have the visual component → brain only receives info from the inner ear and proprioceptors - not from eyes → take away some input the brain gets then it is harder to maintain equilibrium
what is the ampulla?
enlarged regions at the end of the semicircular ducts
Where do the stereo cilia & kinocilia extend? What is this?
entend into the cupula gel-like structure that is "floating" in endolymph
What structure channels sound waves into the ear?
external acoustic meatus (canal)
What happens when we stop spinning clockwise?
fluid is reversed which tells the brain you are now moving counter clockwise → eyes are now jumping to the left (counter-clockwise) trying to maintain balance
What determines where pressure waves strike the cochlear duct?
frequency
What does the tyrannic membrane do?
turns sound waves into vibrations (mechanical waves)
What are some causes of conduction deafness?
tympanic membrane rupture, blockage (ear was, ear plugs, osscles damanged
What is the larger membranous sac that resounds to froward/backward head movements called?
utricle
What is motion sickness or dizziness called?
vertigo
What detects static/stationary equilibrium? Comprised of? Called?
vestibule → two fluid filled sacs 1. saccule 2. utricle
What is the nerve that leaves the cochlea?
vestibulocochlear nerve
How does bone conduction work?
vibrates through and effects the ossicles → you can hear it
What was observed when we picked 3 coins off the floor?
visual aspects of identifying the coins maintained balance
Can conduction deafness be treated?
yes
Was the equilibrium apparatus of the inner ear operating equally well in all the Romberg Tests?
yes → was detecting status/dynamic equilibrium
Were the proprioceptors operating equally well in all the Romberg tests?
yes, proprioceptors are still sending their information to the cerebellum
How is the inner ear described?
→ a bony structure → as a fluid filled tube inside a fluid filled tube
What is conduction deafness?
→ comprised of anything the limits conduction of vibration in the inner ear
