Test Bank

Chapter 7: Motor control

Multiple Choice

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

2. The neurotransmitter at neuromuscular junctions is ______.

a. acetyl choline

b. acetic cholesterase

c. acetyl cholesterase

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

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

5. An alpha motoneuron, together with the muscle fibres that it innervates, forms a(n) ______.

a. motor pool

b. motor unit

c. alpha unit

6. During a graded muscle contraction ______.

a. the smallest fibres contract first

b. the largest fibres contract first

c. fibres of all sizes contract together

7. Muscle spindles are innervated by ______.

a. alpha motoneurons

b. gamma motoneurons

c. sensory nerves

8. Intrafusal muscle fibres are innervated by ______.

a. alpha motoneurons

b. gamma motoneurons

c. sensory nerves

9. 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

10. 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

11. 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

12. The premotor cortex is particularly important in ______.

a. planning internally generated movements

b. coordinating internally generated movements

c. postural control

13. The supplementary motor area is mainly concerned with ______.

a. internally generated movements

b. externally generated movements

c. internally and externally generated movements

14. 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

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

a. primary motor cortex

b. secondary motor cortex

c. cerebellum

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

a. both sensory and motor information

b. only sensory information

c. only motor information

17. 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

18. 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

19. The cerebellum receives cortical input from ______.

a. mossy fibres and climbing fibres

b. mossy fibres and Purkinje cells

c. mossy fibres and granule cells

20. 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

Short Answer Questions

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

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

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

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