Nycc Neuroscience Ii Hearing: The Auditory System

Front 1

Periodic variations in ____ _______ produce sound waves.

Back 1

Air pressure

Front 2

The function of the middle ear is to ____ the ____ so that the signal is not lost in its transition from air to fluid.

Back 2

Enhance, Pressure

Front 3

How fast do the compressions and decompressions of air comprising a sound wave travel?

Back 3

343 m/sec (767 mi/h); the speed of sound

Front 4

What two characteristics is sound characterized by?

Back 4

Frequency, Intesity

Front 5

Frequency determines _____ and is measured in cycles per second or _____.

Back 5

Pitch, Hertz (Hz)

Front 6

What is the range of frequencies audible to humans?

Back 6

20-20,000 Hertz (Hz)

Front 7

Sound with a frequency of more than 20 kHz may be heard by animals such as dogs, cats, mice, and dolphins. What is it called?

Back 7

Ultrasound

Front 8

Sound with a frequency of less than 20 Hz may be heard by animals such as elephants and whales and may be a cause of carsickness. What is it called?

Back 8

Infrasound

Front 9

Intensity determines loudness and is measured in _____ starting from _dB. The loudest tolerable sound is about ___dB.

Back 9

Decibels (dB), 0, 120

Front 10

The external ear is composed of what 2 structures?

Back 10

The Pinna (Auricle or Tragus) and the External Acoustic Meatus (Auditory Canal)

Front 11

What is the Pinna?

Back 11

a cartilaginous sound capturing convoluted funnel

Front 12

The External Acoustic Meatus (Auditory Canal) is a ____ long tunnel that ends at the _____.

Back 12

2.5cm, Eardrum

Front 13

The middle ear is an ___filled chamber composed of: the ____ ____ (a ___diameter conical membrane ); the three _____, ____, ____, and ____; the ____ ____ and ____muscles.

Back 13

Air, Tympanic Membrane, 9mm, Ossicles, Malleus, Incus, Stapes, Tensor Tympani, Stapedius

Front 14

The inner ear (labyrinth) is a ____filled membrane composed of: the ____(auditory system) [a tube that is spiraling _______ times around the conical bony ____]; the ____, the _____canals.

Back 14

Fluid, Cochlea, two and a half, Modiolus, Vestibule, Semicircular

Front 15

The sound waves cause _____ of the Tympanic membrane which is transmitted to the ____.

Back 15

Displacement, Ossicles

Front 16

The tympanic membrane has a ____shape whose ____portion extends into the cavity of the middle ear and onto which the ____is attached.

Back 16

Conical, Convex, Malleus

Front 17

The Malleus, Incus and Stapes are held together by tiny ____ ____.

Back 17

Synovial Joints

Front 18

The middle ear amplifies the pressure by 2 ways: the surface area of the ____ window is 17 times smaller than that of the ____ ____ and the ____ act as levers and _____ the force output on the ____ window.

Back 18

Oval, Tympanic membrane, Ossicles, Increase, Oval

Front 19

The stapes’s footplate pistons in and out onto the ____ ____ thus transferring the ____ ____ displacement to the ____ ____.

Back 19

Oval window, Tympanic membrane, Inner ear

Front 20

If the middle ear did not function only __% of the energy would be transferred from external to inner ear as compared to __% that actually does.

Back 20

2, 67

Front 21

The middle ear cavity connects to the nasopharynx via the ____ ____.

Back 21

Eustachian tube

Front 22

In the middle ear, the movement on the footplate of the ____ is 1.3 times the movement of the arm of the ____.

Back 22

Stapes, Malleus

Front 23

The tensor tympani attaches to the ____while the _____to the stapes.

Back 23

Malleus, Stapedius

Front 24

The base of the Cochlea has two ____ ____ holes at its base which faces the middle ear: the ____ window and the ____window.

Back 24

Membrane covered, Oval, Round

Front 25

the Eustachian tube (auditory tube) is usually closed by a ____ and the ____ air space (antrum) via the ____.

Back 25

Valve, Mastoid, Aditus

Front 26

The middle ear muscles' function is to make the ossicles more ___ in order to ____ very ____sounds ( ____ them by __dB).

Back 26

Rigid, Dampen, Loud, Decreases, 10

Front 27

When the oval window is displaced by the stapes, what happens?

Back 27

it causes fluid movement

Front 28

Any energy not absorbed by the fluid in the Cochlea ultimately distorts what?

Back 28

the Round Window

Front 29

The sound has to travel from the ___filled external and middle ear to the ___filled inner ear.

Back 29

Air, Fluid

Front 30

Sound below 20Hz is known as ______, above 20kHz: _________.

Back 30

Infrasound, Ultrasound

Front 31

What are the muscles of the inner ear? What are they innervated by?

Back 31

Tensor tympani & Stapedius muscles, Facial Nerve VII

Front 32

The Cochlea spirals around what?

Back 32

Bony Modiolus

Front 33

The Tensor tympani connects to the _______ and functions for what purpose?

Back 33

Malleus, Makes ossicles more rigid to protect against loud sounds

Front 34

Why do sudden loud sounds hurt?

Back 34

Tensor Tympani and Stapedius muscles' Attenuation reflex works after a 50-150 millisecond delay

Front 35

How does the middle ear amplify the sound pressure 22 times?

Back 35

Large surface (Tensor Tympani) to small surface (Oval Window) and ossicles act as levers to transfer energy

Front 36

Displaced by the stapes, the _____ window causes _____; any unabsorbed energy distorts the ______ window.

Back 36

Oval, Fluid movement, Round

Front 37

The membranes are located at the ______ of the Cochlea.

Back 37

Body

Front 38

Where is the Basilar membrane widest?

Back 38

At the apex of the Cochlea

Front 39

The extracellular space of detector cells contains _______.

Back 39

K+

Front 40

The Scalas Vestibuli (SV) and Scalas Tympani (ST) contain _______, which is rich in ______ and continuous with ______.

Back 40

Perilymph, Na+, Cerebrospinal Fluid

Front 41

Name in order the 2 spaces & 2 structures of the cochlea.

Back 41

Scala Vestibuli, Reissner’s Membrane, Scala Media, Basilar Membrane,

Front 42

The Scala Media contains _______, which is rich in ____ due to the _______ secreting K+ while ______.

Back 42

Endolymph, K+, Stria Vascularis, absorbing Na+

Front 43

What is the sensory structure on the Basilar membrane?

Back 43

Organ of Corti

Front 44

How is sound coded in the Basilar membrane?

Back 44

Base (narrow & rigid ) = high frequency,
Apex (wide & floppy ) = low frequency (Tonotopically)

Front 45

The Basilar membrane is wide at the _____ of the Cochlea.

Back 45

Apex

Front 46

Organ of Corti contains ______ of Corti, _____ & _____ cells, and ________ cells.

Back 46

Rods, Inner hair, Outer hair, Supporting

Front 47

Organ of Corti sits on the _________ membrane and is covered by the __________ membrane.

Back 47

Basilar, Tectorial

Front 48

What action produces the Receptor potential at the hair cell?

Back 48

the Bending of the ~100 Sterocilia of each hair cell

Front 49

Which hair cells have Stereocilia extending into the Tectorial membrane?

Back 49

Outer hair cells

Front 50

Inner hair cells synapse with the _________ cells, the axons of which form the __________.

Back 50

Bipolar Spiral ganglion, Cochlear nerve

Front 51

Which hair cells are distal to the Pillar cells?

Back 51

Outer hair cells

Front 52

What sequence happens when sterocilia bend due to upward movement of the Tectorial membrane?

Back 52

K+ channels open -> Depolarization, Ca+ channels open ->Neurotransmitter (Glu) releases -> Synapse between hair cells & Spiral ganglion dendrites

Front 53

Downward movement of the Basilar membrane causes __________.

Back 53

Hyperpolarization

Front 54

How do we know that outer hair cells may deal with amplification?

Back 54

Ototoxic antibiotics destroy them leading to hearing loss

Front 55

About how many Spiral ganglion cells are there?

Back 55

30,000

Front 56

Spiral ganglion cells form the _________ and later synapse with the ___________.

Back 56

Cochlear nerve, Cochlear nuclei (in the Medulla)

Front 57

Each fiber of the Spiral ganglion holds a specific frequency, thus is has ______________.

Back 57

Tonotopic organization

Front 58

What 2 types of cells are in the ventral Cochlear nuclei and what do they do?

Back 58

Stellate (frequency encoding), Bushy (fire at sound onset and aid in horizontal localization)

Front 59

What 2 type of cells are in the dorsal Cochlear nucleus and what do they do?

Back 59

Fusiform (freqency encoding, aid in vertical sound localization), Tuberculoventral (respond with delay, inhibit echo interference)

Front 60

If you lesion one side after the Cochlear nuclei what would result?

Back 60

Bi-lateral hearing loss more pronounced contralaterally

Front 61

How is horizontal localization achieved?

Back 61

the Medial Olivary Nucleus processes auditory time delay between ears

Front 62

During exposure to what is interaural time delay the most striking? Interaural intensity?

Back 62

Low frequencies, High frequencies

Front 63

In addition to round window distention, how are echos avoided?

Back 63

Hyperpolarization and Resting phases

Front 64

Intensity difference between the two ears is detected by the _________.

Back 64

Lateral superior Olivary nucleus

Front 65

The Cochlear nuclei fibers synapse _______ with the _______, who’s fibers form the ______

Back 65

Bilaterally, Superior Olivary Nuclei, Lateral lemniscus

Front 66

Some fibers from the lateral Lemniscus synapse with the ____, but most synapse with the ____.

Back 66

Nucleus of the lateral Lemniscus, Inferior Colliculus

Front 67

Describe the Inferior Colliculus.

Back 67

4-layer, Dorsal (Auditory & Somatosensory), Multi-central nucleus with complete Tonotopic map

Front 68

The __________ holds a complete ________ and receives fibers from the inferior Colliculus.

Back 68

Medial Geniculate nucleus, Somatotopic map

Front 69

What is the primary auditory cortex?

Back 69

Transverse Temporal Gyri of Heschl (Brodmann's areas 41 & 42, near superior Temporal gyrus)

Front 70

Conductive hearing loss results from _____________.

Back 70

Insult to the middle ear

Front 71

Sensorineural hearing loss results from ________________.

Back 71

Loss of Cochlear hair cells

Front 72

What does Otosclerosis result in?

Back 72

Ossification of Ossicle attachments

Front 73

What may Otitis media result in?

Back 73

Formation of scar tissue that hinders the movement of the Tympanic membrane or the Ossicles

Front 74

The Transverse Temporal Gyrus of Heschl is ____ organized and is the second point of what?

Back 74

Tonotopically, Localization of sound (it has columns responsive to every audible frequency and interaural relationship)

Front 75

Where is the tuning fork placed in Weber’s test?

Back 75

Vertex or Nasion

Front 76

In Weber’s test, sound lateralizes towards the ear with ______ deafness, and away from the ear with ______ deafness.

Back 76

Conductive, Sensorineural

Front 77

Where is the tuning fork placed in Rinne’s test?

Back 77

Start: Mastoid process, Later: by ear when tuning fork is quieter

Front 78

In Rinne's test, if the patient cannot hear the tuning fork after it is moved by the ear, ___________ loss is suspected.

Back 78

Conductive