Week 10: Auditory and Vestibular Systems

Question 1

Which cranial nerves are responsible for the motor output of the vestibulo-ocular reflex (VOR)?

Answer 1

III - Occulomotor
IV - Trochlear
VI - Abducens

Question 2

The distance between successive compressed patches of air is called:

a. Cycle
b. Hertz
c. Audition
d. Vestibular
e. Amplitude

Answer 2

a. Cycle

Question 3

What is the range of human hearing?

Answer 3

20 Hz to 20,000 Hz

Question 4

The outer ear consists of: (Select all that apply):

a. Pinna
b. Tympanic membrane
c. Cochlea
d. Ossicles
e. Auditory canal
f. Oval window

Answer 4

a. Pinna

e. Auditory canal

Question 5

Describe how the ossicles amplify sound force.

Answer 5

– Pressure: force per surface area
– Greater pressure at oval window than tympanic
membrane, moves fluids.

Question 6

Which reflect involves the contraction of the tensor tympani and stapedius muscle?

a. The vestibulo-ocular reflex
b. The tympani-audio reflex
c. The attenuation reflex
d. The ossicles reflex

Answer 6

c. The attenuation reflex

Question 7

Which of the following is CORRECT regarding perilymph?
Select one:

a. It has an ionic content similar to cerebrospinal fluid
b. It is fluid in the scala media
c. it has ionic concentration similar to intracellular fluid (high K+ and low Na+)
d. It is 80mV more positive than endolymph

Answer 7

a. It has an ionic content similar to cerebrospinal fluid

Corrections:
b & c apply to endolymph; endolymph is 80mV more positive than perilymph.

Question 8

The middle are consists of:

a. Pinna
b. Tympanic membrane
c. Cochlea
d. Ossicles
e. Auditory canal
f. Oval window

Answer 8

b. Tympanic membrane

d. Ossicles (malleus, incus and stapes)

Question 9

What role are outer hair cells suspected to have?

a. pitch discrimination
b. cochlear amplification
c. sound localization on the horizontal plane
d. sound localization on the vertical plane

Answer 9

b. cochlear amplification

Motor proteins:
change length of
outer hair cells - reduces space between tectorial membrane and basilar membrane

Question 10

High pitch sounds have:

a. low frequency
b. high frequency
c. low amplitude
d. high amplitude

Answer 10

b. high frequency

Question 11

What is the attenuation reflex>

Answer 11

Response when onset of loud sound causes
tensor tympani and stapedius muscle
contraction
– Function: adapts ear to loud sounds, protects
inner ear, enables us to understand speech
better