Question 1

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

Accepted Answer

The cochlea is primarily responsible for hearing and does not respond to movements of the head, unlike the utricle, saccule, and semi-circular canals, which are involved in balance and spatial orientation.

Question 2

When the head is upright, the utricular macula is:

Accepted Answer

The utricular macula is oriented horizontally when the head is in an upright position. This orientation allows it to detect horizontal movements and the effects of gravity.

Question 3

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

Accepted Answer

The semi-circular canals signal appropriate head rotation because the endolymph (the fluid within the canals) lags behind the movement of the head due to inertia. This relative movement of the endolymph to the canal stimulates hair cells in the ampulla to send signals to the brain about head rotation.

Question 4

Rotation in yaw is:

Accepted Answer

Rotation in yaw refers to the turning of an object around its vertical axis, similar to how a car turns left or right.

Question 5

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

Accepted Answer

Pedalling on an exercise bicycle does not directly stimulate the vestibular system, which is involved in balance and spatial orientation. The other options (B, C, D) are methods that have been used to stimulate or assess the vestibular system.

Question 6

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

Accepted Answer

The medial geniculate nucleus of the thalamus is involved in the auditory pathway, not in the vestibular system, which is concerned with balance, spatial orientation, and coordination. The vestibular system sends projections to the oculomotor system, spinal cord, and cerebellum to help maintain balance and posture, coordinate head and eye movements, and process spatial orientation.

Question 7

If the left vestibular system is damaged:

Accepted Answer

The vestibulo-ocular reflex (VOR) is a mechanism that stabilizes gaze during head movement by producing eye movements in the direction opposite to head movement. Damage to the left vestibular system would impair the VOR towards the left, as the left system is responsible for detecting head movements to the left and coordinating the appropriate compensatory eye movement to the right.

Question 8

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

Accepted Answer

The lowest rotary velocity that can be detected by the vestibular system is approximately 0.5 degrees per second. This sensitivity allows the vestibular system to detect very slow movements, helping maintain balance and spatial orientation.

Question 9

The oculogravic illusion is:

Accepted Answer

The answer of The oculogravic illusion is:
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Question 10

Motion sickness results from:

Accepted Answer

Motion sickness occurs when there is a conflict between the sensory information received from the eyes, inner ear, and body, and what the brain expects based on previous experiences and motor commands. This sensory mismatch leads to symptoms of motion sickness.

Question 11

Muscle spindles are found:

Accepted Answer

Muscle spindles are sensory receptors within the belly of a muscle that primarily detect changes in the length of the muscle. They are found on intrafusal fibers, not on extrafusal fibers, gamma fibers, or tendons.

Question 12

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

Accepted Answer

Mechanoreceptors around the joints respond to joint position, movement or acceleration, and overextension of the joint, but they do not specifically respond to the lack of exercise of the joint.

Question 13

Efferent gamma fibres to intrafusal muscle fibres cause:

Accepted Answer

Efferent gamma fibers innervate the striated ends of intrafusal muscle fibers, causing them to contract and thereby increasing the sensitivity of the central regions to stretch.

Question 14

Proprioceptive acuity in a knee or finger joint is about:

Accepted Answer

Proprioceptive acuity in a knee or finger joint is about 1 degree, indicating a very fine level of sensitivity to joint position changes.

Question 15

Someone who lacks proprioception cannot:

Accepted Answer

The answer of Someone who lacks proprioception cannot:
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Question 16

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

Accepted Answer

The perceived position of the hand is indeed a compromise between proprioception (sense of body position) and vision, with the brain integrating information from both modalities to determine the hand's position. This integration can depend on the relative clarity or availability of sensory information from each source.

Question 17

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

Accepted Answer

Van Beers et al. found that the integration of proprioceptive and visual information is influenced by the precision of the information from each modality, with more weight given to the more precise modality.

Question 18

Movements of the body are sensed:

Accepted Answer

Movements of the body are sensed through a combination of inputs from proprioceptors in neck muscles and the vestibular system. Proprioceptors provide information about the position of the body parts in relation to each other, while the vestibular system in the inner ear gives information about balance and spatial orientation.

Question 19

A common symptom in astronauts on arrival in space is:

Accepted Answer

Motion sickness is a common symptom experienced by astronauts due to the microgravity environment in space, which affects the vestibular system responsible for balance and spatial orientation.

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?

Accepted Answer

The answer of From the results of the Functional Mobility...

Quiz 9: Vestibular and Proprioceptive Systems