The Auditory And Vestibular Systems

Front 1

Sense of hearing

Back 1

audition

Front 2

Sense of balance

Back 2

Vestibular system

Front 3

Frequency of sound

Back 3

Number of compressed or rarefied patches of air that pass by our ears each second. Measured in HERTZ.

Front 4

Intensity

Back 4

The difference in pressure between compressed and rarefied patches of air.

Front 5

Pinna

Back 5

Funnel shaped.
-Helps collect sound from a wide area.
-Cartilage

Front 6

Entrance to the internal ear

Back 6

Auditory canal

Front 7

Tympanic Membrane

Back 7

End of auditory canal
-Connected to ossicles

Hint 7

AKA ear drum

Front 8

Ossicles

Back 8

-Series of bones
-Transfer movements of the tympanic membrane into movements of the second membrane covering a hole in the skull called the oval window.

Front 9

Cochlea

Back 9

-Behind oval window
-Fluid-filled
-Contains apparatus for transforming physical motion of the oval window membrane into neuronal response.

Front 10

The region extending from the pinna to the tympanic membrane

Back 10

Outer ear

Front 11

Tympanic membrane to the ossicles is the region called the ____.

Back 11

Middle ear

Front 12

Apparatus medial to the oval window

Back 12

Inner ear

Front 13

Medial Geniculate Nucleus (MGN)

Back 13

-Neural response is projected from the inner ear to the nuclei in the brain stem. The output from these are projected to the MGN. The MGN projects the neural response to the primary auditory cortex (A1) in the temporal lobe.

Front 14

Malleus

Back 14

-Hammer
-The ossicle attached to the tympanic membrane
-Forms rigid connection with the incus.

Front 15

Incus

Back 15

-Rigidly connected to malleus
-Ossicle
-Flexibly connected to stapes

Front 16

Stapes

Back 16

-Flexibly connected to Incus
-Ossicle
-The flat bottom portion of the stapes (footplate) moves in and out like a piston at the oval window thus transmitting sound vibrations to the fluids of the cochlea in the inner ear.

Front 17

Eustachian Tube

Back 17

-Usually closed by a valve
-Air in middle ear
-When pressure goes ^ = unpleasant feeling in ear bc of eustachian tube

Front 18

Attenuation reflex

Back 18

-Loud sound triggers the tensor tympani muscle and the stapedius muscle to contract
-Diminishes sound conduction of inner ear

Front 19

Round window

Back 19

-Counterpart of the oval window
-Base of cochlea
-Membrane covered hole

Front 20

What are the three fluid-filled chambers of the cochlea?

Back 20

-Scala vestibuli
-Scala media
-Scala tympani

Front 21

Reissner's Membrane

Back 21

-Separates scala vestibuli from the scala the scala media.

Front 22

Basilar Membrane

Back 22

-Separates the scala media from the scala tympani.

Front 23

Organ of Corti

Back 23

-Contains auditory receptor neurons
-Located on basilar membrane

Front 24

Tectorial membrane

Back 24

-Hangs over the organ of Corti

Front 25

Helicotrema

Back 25

-Where the scala tympani becomes continues with the scala vestibuli.
-Hole in membranes

Front 26

What is thehe fluid in the scala vestibuli, and the scala tympani called, and what is its ionic content?

Back 26

Perilymph
-Low K+, High Na+

Front 27

What is the fluid and ionic content of the scala media?

Back 27

Endolymph
-High K+, Low Na+

Front 28

Hair cells

Back 28

-Auditory receptors
-Each one has 100 hairy-looking stereocilia extending from its top.
-Located on the organ of Corti

Front 29

Reticular Lamina

Back 29

-Thin sheet of tissue
-Abuts hair cells

Front 30

Inner hair cells

Back 30

-Hair cells between the the modiolus and the rods of Corti

Front 31

Outer hair cells

Back 31

-Cells farther out than the rods of Corti

Front 32

Rods of Corti

Back 32

-Span the reticular lamina and the basilar membrane
-Provide structural support

Front 33

Spiral ganglion

Back 33

-Location of where hair cells form synapses on neurons (cell bodies are in the spiral ganglion)
-Spiral ganglion cells are bipolar, with neurites extending to the bases and sides of the hair cells, where they receive synaptic input.

Front 34

Auditory-Vestibular Nerve

Back 34

-Cranial Nerve VIII
-Projects to the cochlear nuclei in the medulla

Front 35

Cochlear Amplifier

Back 35

-Outer hair cells on the basilar membrane
-Amplify movement of the basilar membrane during low-intensity sound stimuli.

Front 36

Superior Olive

Back 36

-On both sides of brain stem
-Where cells in the ventral cochlear nucleus are projected.

Front 37

Inferior colliculus

Back 37

-Axons from superior olive ascend in the lateral lemniscus and innervate this structure.

Front 38

Characteristic frequency

Back 38

-Each neuron is most responsive at specific frequency, called the characteristic frequency.

Front 39

Tonotopy

Back 39

-Systematic organization of characteristic frequency.
-Retinotopy/somatotopy
-Mapping

Front 40

Phase locking

Back 40

-The consistent firing of a cell at the same phase of a sound wave

Front 41

Volley principle

Back 41

-It is likely that intermediate sound frequencies are represented by the pooled activity of a number of neurons, each of which fires in a phase-locked manner.

Front 42

Interaural time delay

Back 42

-If noise comes from your right, will reach left ear later.

Front 43

Duplex Theory of Sound Localization

Back 43

-Interaural time delay + interaural intensity difference

Front 44

Interaural Intensity Difference

Back 44

-Head casts a sound shadow
-Lower intensity depending on where sound is

Front 45

Vestibular Labyrinth

Back 45

-All hair cells contained within sets of interconnected chambers