Psychology MCQ: Control of Body Movement

After stretching an intrafusal fiber, the next event is

A) an increase in action potentials along the associated sensory neuron.
B) a decrease in muscle tension.
C) a decrease in muscle tone.
D) decreased sensitivity to stretching.
E) All of the answers are correct.

Answer: A

When there is a resistance to the movement produced by a given limb muscle,

A) gamma motor neurons are inhibited by higher brain centers.
B) there is a decrease in the amount of force generated by extrafusal muscle fibers.
C) the muscle involved in the movement immediately shortens when stimulated.
D) intrafusal fibers receive fewer action potentials from the gamma motor neurons.
E) muscle tone is increased and more motor units are recruited to the contraction.

Answer: E

Ten-year-old Tina falls while climbing a tree and lands on her back. Her frightened parents take her to the local emergency room where she is examined. Her knee jerk reflex is normal and she exhibits a negative Babinski reflex. These results suggest that

A) Tina has injured one of her descending nerve tracts.
B) Tina has injured one of her ascending nerve tracts.
C) Tina has a spinal injury in the lumbar region.
D) Tina has a spinal injury in the cervical region.
E) Tina suffered no damage to her spinal cord.

Answer: E

The structure whose abnormal function is associated with Parkinson's disease is the

A) spinal cord.
B) basal ganglia.
C) cerebellum.
D) primary motor cortex.
E) skeletal muscle.

Answer: B

Interneurons of the corticospinal tract synapse onto

A) visceral efferents.
B) somatic efferents.
C) interneurons of central pattern generators.

Answer: B

Most reflexes are regulated by

A) the brain.
B) the spinal cord.
C) ganglia.
D) positive feedback.
E) negative feedback.

Answer: E