Deck 9: Vestibular and Proprioceptive Systems

Question 1

Which of the following structures in the inner ear does not respond to movements of the head?

A) Utricle
B) Cochlea
C) Saccule
D) Semi-circular canal

Answer 1

B

Question 2

When the head is upright, the utricular macula is:

A) Horizontal
B) Vertical
C) At 45 deg from vertical
D) None of these

Answer 2

A

Question 3

The semi-circular canals are able to signal appropriate head rotation because:

A) The ampulla rotates
B) The otoliths have a higher specific weight than does the endolymph
C) The endolymph lags behind the movement of the head
D) The cilia are encased in jelly

Answer 3

C

Question 4

Rotation in yaw is:

A) Rotation about the x-axis
B) Like a forward roll
C) Like a cartwheel
D) Rotation about the vertical axis

Question 5

Which of the following has not been used to stimulate the vestibular system?

A) Pedalling on an exercise bicycle
B) Movement on a centrifuge
C) Warm water injected into the ear canal
D) Direct current through electrodes on the mastoids

Question 6

To which of the following, does the vestibular system not send projections?

A) The oculomotor system
B) The spinal cord
C) The cerebellum
D) The medial geniculate nucleus of the thalamus

Question 7

If the left vestibular system is damaged:

A) The vestibulo-ocular reflex towards the left is abnormal
B) The vestibulo-ocular reflex in any direction is abnormal
C) The vestibulo-ocular reflex towards the right is abnormal
D) The vestibulo-ocular reflex is unaffected

Question 8

What is the lowest rotary velocity that can be detected by the vestibular system?

A) 4 deg s⁻¹
B) 0.5 deg s⁻¹
C) 10 deg s⁻¹
D) 2 deg s⁻¹

Question 9

The oculogravic illusion is:

A) A feeling that the eyes have moved
B) Misperception of vertical during linear acceleration
C) Misperception of horizontal during linear acceleration
D) A change in the perception of gravity

Question 10

Motion sickness results from:

A) A mismatch between sensory information and what would be expected to result from motor commands
B) An abnormal vestibular system
C) An imbalance of digestive enzymes
D) Rotary motion

Question 11

Muscle spindles are found:

A) On extrafusal cells
B) On gamma fibres
C) On intrafusal cells
D) On tendons

Question 12

To which stimulus, do mechanoreceptors around the joints not respond ?

A) Joint position
B) Movement or acceleration
C) Overextension of the joint
D) Lack of exercise of the joint

Question 13

Efferent gamma fibres to intrafusal muscle fibres cause:

A) The muscle to contract
B) An improvement in muscle tone
C) Contraction of the striated ends of the fibres, so making the central regions more sensitive to stretch
D) Increased sensitivity of Golgi tendon organs

Question 14

Proprioceptive acuity in a knee or finger joint is about:

A) 1 deg
B) 10 deg
C) 30 seconds
D) 5 deg

Question 15

Someone who lacks proprioception cannot:

A) Drive
B) Walk
C) With eyes closed, draw shapes in the air with a hand
D) With eyes closed, judge the weight of an object placed on the hand

Question 16

When initially viewed through a prism, a hand looks and feels to be in different positions. In this situation:

A) Vision always dominates touch, so that the hand is perceived in the seen position
B) Touch always dominates vision, so that the hand is perceived in the felt position
C) Perceived position is a compromise between proprioception and vision, which depends on the relative availability of information in the two modalities
D) None of these

Question 17

Van Beers et al. showed that the combination of proprioceptive and visual information depended on:

A) The precision of the information from each modality
B) The observer's personality
C) The variance of visually controlled reaches
D) The force required to make a movement

Question 18

Movements of the body are sensed:

A) From proprioceptors in neck muscles
B) From a combination of inputs from proprioceptors in neck muscles and the vestibular system
C) From proprioceptors in the spine
D) Via input from leg joints

Question 19

A common symptom in astronauts on arrival in space is:

A) An oculogyral illusion
B) Disorientation
C) Motion sickness
D) Aching in the joints

Question 20

From the results of the Functional Mobility Test, how long does it take for 95% of re-adaptation to earth's gravity to occur?

A) 3 weeks
B) 1 month
C) 3 days
D) 15 days

Question 21

When the head is upright, the saccular macula is:

A) Horizontal
B) Vertical
C) At 45 deg from vertical
D) None of these

Question 22

The movement known as 'pitch' is:

A) Rotation about the y-axis
B) A pirouette
C) Forward motion
D) Rotation about the z-axis

Question 23

A horizontal rotation which produces an increase in firing in the nerve fibres leaving the horizontal canal of the left ear has what effect on the right vestibular system?

A) Increases the signal from the anterior canal
B) Reduces the signal from the posterior canal
C) Reduces the signal from the horizontal canal
D) Reduces the signal from the utricle

Question 24

The gain of the vestibulo-ocular reflex is set by:

A) The elasticity of the eye muscles
B) Feedback about its effects on vision
C) Frontal cortex
D) None of these

Question 25

Motion sickness in vehicles tends to:

A) Be worse in the driver
B) Be worse in passengers
C) Be worse in front seats
D) None of these

Question 26

The number of muscle spindles is lowest in the muscles of the:

A) Eyes
B) Fingers
C) Shoulder
D) Neck

Question 27

Vestibular nuclei respond when:

A) The head is held stationary and the body rotated
B) Signals from the vestibular system and neck proprioceptors are matched
C) During passive motion of the whole participant
D) The legs move

Question 28

Patient IW, who lacks proprioception and sense of touch below the neck, has taught himself to walk and carry out some everyday tasks. However, his motor control fails when:

A) He cannot see his limbs
B) He tries to drive
C) He tries to feed himself
D) He concentrates too hard on what he is doing

Question 29

After repeatedly viewing a pointing hand through a prism which changes its seen position, the observer makes pointing movements without the prism. These movements initially:

A) Are accurate
B) Deviate in the same direction as the change in vision induced by the prism
C) Deviate in the opposite direction to the change in vision induced by the prism
D) Are random

Question 30

After a return to earth from a lengthy trip in space, which system re-adapts most quickly to earth's gravity?

A) Control of the arms
B) Control of the legs
C) The otoliths
D) None of these

Question 31

Describe techniques for stimulating the vestibular system, and their advantages and disadvantages.

Question 32

How does the arrangement of the vestibular organs allow detection of complex movements of the head?

Question 33

How does the brain sense movements of the body?

Question 34

Describe the proprioceptive receptors and their properties.

Question 35

What sources of information contribute to acuity for the position of a joint?