Deck 6: Motor Control

Question 1

The different properties of fast and slow muscle fibres arise from differences in their ______.

A) proportions of actin and myosin
B) types of actin and myosin
C) energy-releasing enzymes

Answer 1

C

Question 2

The neurotransmitter at neuromuscular junctions is ______.

A) acetyl choline
B) acetic cholesterase
C) acetyl cholesterase

Answer 2

A

Question 3

During muscle contraction, the tips of ______.

A) myosin filaments 'row' along actin filaments
B) actinomyosin shortens by coiling
C) actin filaments 'row' along myosin filaments

Answer 3

A

Question 4

The cell bodies of alpha motoneurons are ______.

A) outside the spinal cord
B) in the dorsal horn of the spinal cord
C) in the ventral horn of the spinal cord

Question 5

During a graded muscle contraction ______.

A) the smallest fibres contract first
B) the largest fibres contract first
C) fibres of all sizes contract together

Question 6

Muscle spindles are innervated by ______.

A) alpha motoneurons
B) gamma motoneurons
C) sensory nerves

Question 7

Intrafusal muscle fibres are innervated by ______.

A) alpha motoneurons
B) gamma motoneurons
C) sensory nerves

Question 8

Activation of muscle spindles causes ______.

A) contraction of the antagonist muscle
B) contraction of the agonist muscle
C) contraction of the agonist and antagonist muscles

Question 9

The bodies of sensory nerves are located in ______.

A) the dorsal root ganglia
B) the dorsal horn of the spinal cord
C) the ventral horn of the spinal cord

Question 10

The secondary motor cortex outputs ______.

A) only directly via the spinal motor tracts
B) only indirectly via the primary motor cortex
C) both directly via the spinal motor tracts and indirectly via the primary motor cortex

Question 11

The premotor cortex is particularly important in ______.

A) planning internally generated movements
B) coordinating internally generated movements
C) postural control

Question 12

The supplementary motor area is mainly concerned with ______.

A) internally generated movements
B) externally generated movements
C) internally and externally generated movements

Question 13

The striatum projects to the output of the basal ganglia by ______.

A) a direct inhibitory route
B) an indirect excitatory route
C) a direct excitatory route

Question 14

The main output of the posterior parietal cortex is to the ______.

A) primary motor cortex
B) secondary motor cortex
C) cerebellum

Question 15

The forward plan produced by the posterior parietal cortex includes ______.

A) both sensory and motor information
B) only sensory information
C) only motor information

Question 16

When the eyes are moved passively, without an eye movement command, the visual world ______.

A) appears to move in the same direction as the eye movement
B) appears to move in the opposite direction to the eye movement
C) does not appear to move

Question 17

The part of the posterior parietal cortex concerned with arm movements is called ______.

A) the posterior reach region
B) the parietal pointing region
C) the parietal reach region

Question 18

The cerebellum receives cortical input from ______.

A) mossy fibres and climbing fibres
B) mossy fibres and Purkinje cells
C) mossy fibres and granule cells

Question 19

The cerebellum helps us adapt to a visual displacing prism by ______.

A) bringing visual information into line with proprioceptive information
B) bringing proprioceptive information into line with visual information
C) consciously compensating for perceived visual error

Question 20

Outline the sequence events that occur between the arrival of an action potential at a neuromuscular junction and the contraction of a muscle fibre.

Question 21

What role do spinal circuits play in simple movements and how might they contribute to more complex movements?

Question 22

Explain how the various parts of the motor control system might be involved in the act of picking up a pencil.

Question 23

What is a forward plan? Give examples of how and why a forward plan might be important in three different actions.