Exam 4 Auditory

Question 1

Where are the auditory and vestibular receptors located?

Answer 1

In the inner ear, deep inside the temporal bone

Question 2

What is the membranous labyrinth filled with?

Answer 2

Endolymph

Question 3

What fluid lies between the membranous labyrinth and the body labyrinth?

Answer 3

Perilymph

Question 4

What does the auditory apparatus consist of?

Answer 4

the cochlea

Question 5

What does the vestibular apparatus consist of?

Answer 5

Three semicircular canals or ducts and a pair of otoliths called utricle and the saccule

Question 6

What are the three different cavities that sound waves must travel through?

Answer 6

Outer ear, external auditory meatus, and the middle ear.

Question 7

What is the opening in the cochlea with which the stapes is in contact with?

Answer 7

Oval window

Question 8

How many times does the cochlea spiral?

Answer 8

2 and 1/2 times

Question 9

What are the three fluid filled compartments in the cochlea?

Answer 9

Scala vestibuli, scala tympani, and scala media

Question 10

On which side of the duct is the scala vestibuli located? Scala tympani?

Answer 10

Oval window side.

Round window side

Question 11

In what structure of the cochlear duct house are the sensory receptors housed?

Answer 11

Organ of Corti

Question 12

What puts pressure on fluid in the scala vestibuli?

Answer 12

Vibration of the stapes and oval window

Question 13

Why is there inward and outward movement of the round window of the scala tympani?

Answer 13

Because fluid is incompressible

Question 14

Where does the organ of Corti sit?

Answer 14

Sits on the basilar membrane

Question 15

What are the hair cells of the organ of corti stimulated by?

Answer 15

Movement of the basilar membrane

Question 16

What kind of axons are the hair cells innervated by?

Answer 16

afferent and efferent of CN VIII

Question 17

What opens the ion channels in the hair cells?

Answer 17

the bending of the stereocilia

Question 18

What flows thru the ion channels to generate a receptor potential in the hair cell?

Answer 18

Cations

Question 19

The base of the cochlea handles what range of sound frequency? The apex?

Answer 19

High frequency (15000Hz).
Low frequency (100Hz)

Question 20

The apex of the cochlea is also called the

Answer 20

helicotrema

Question 21

Where are the short and stiff stereocilia in the cochlea? Where are the twice as long stereocilia?

Answer 21

On hair cells at the base of the cochlea. Long stereo cilia are at the apex.

Question 22

How mane rows of inner hair cells are there? How many rows of outer hair cells?

Answer 22

One row of inner and three rows of outer hair cells.

Question 23

Which hair cells can alter their length?

Answer 23

The outer hair cells

Question 24

Where are the dorsal and ventral cochlear nuclei?

Answer 24

In the upper medulla

Question 25

Where do most fibers decussate of the Central Auditory Pathway (8CSLIMA)?

Answer 25

Lower pons and ascend in the lateral lemniscus

Question 26

Where do the decussating fibers of the CAP synapse?

Answer 26

Some synapse in the superior olivary nuclear complex and some in the reticular formation.

Question 27

A unilateral lesion of the CAP would cause hearing loss on what side of the head?

Answer 27

On the side opposite of the lesion

Question 28

Where do fibers from the lateral lemniscus synapse?

Answer 28

in the inferior colliculus

Question 29

Where do CAP axons go from the inferior colliculus?

Answer 29

Medial geniculate of the diencephalon

Question 30

Where do neurons in the medial geniculate send their axons?

Answer 30

to the primary auditory cortex, via what's called the auditory radiations

Question 31

Where is the primary auditory cortex located?

Answer 31

in the transverse temporal gyri

Question 32

What are the three functions of the CAP?

Answer 32

Conscious hearing, orientation/localization of sound, and CNS activation/alertness.

Question 33

Where is the conscious hearing of sound processed?

Answer 33

Primary auditory Cortex

Question 34

Where is the orientation/localization of sound processed?

Answer 34

Superior Olivary Nucleus and Inferior Colliculus

Question 35

Where is CNS activation/alertness of sound processed?

Answer 35

Reticular formation

Question 36

Which muscle inserts into the malleus? What is its innervation?

Answer 36

Tensor tympani. CN V

Question 37

What is the function of the tensor tympani muscle?

Answer 37

To dampen vibration of the tympanic membrane in response to loud noise

Question 38

Which muscle inserts into the stapes? What is its innervation?

Answer 38

Stapedius. CN VII

Question 39

What is the function of the stapedius muscle?

Answer 39

To dampen vibration of stapes in response to loud noise

Question 40

What is presbycusis?

Answer 40

reduced ability to hear high frequency sounds, degenerative disease of the organ of corti

Question 41

T/F Unilateral lesion of the ascending auditory pathway causes bilateral diminution of hearing, but more marked on the contralateral side?

Answer 41

True

Question 42

Do lesions of the auditory cortex disrupt the perception of sound? Do they affect the ability to localize sounds in space?

Answer 42

No. Yes.

Question 43

On which side of the cochlea is the basilar membrane?

Answer 43

Scala tympani

Question 44

What is the ascending portion of the cochlea?

Answer 44

Scala Vestibuli

Question 45

What is the descending portion of the cochlea?

Answer 45

Scala tympani

Question 46

What are the hair cells closely covered by?

Answer 46

tectorial membrane

Question 47

What triggers the hair cells to fire?

Answer 47

Movement of the tiny clusters of hairs against the tectorial membrane

Question 48

What is tonotopic organization?

Answer 48

The lower frequencies vibrate the basilar membrane closer to the apex of the cochlea, while higher frequencies produce vibrations closer to the base.