Answer & Explanation
The correct answer is (C).
The axons of the pyramidal cells of the motor cortex descend
to synapse on lower motor neurons in the brain stem and the
spinal cord. Since there are no intervening synapses, the
pyramidal system is able to provide rapid commands to the
skeletal muscles and various other organs. There are several
other centers that can issue somatic motor commands as a result
of processing performed at the unconscious, involuntary level.
These centers and their associated tracts comprise the
extrapyramidal system. The red nucleus, located in the
mesencephalon, is the component of the extrapyramidal system
primarily in control of skeletal muscle tissue.
The cerebellar nuclei (choice A), located in the cerebellum,
primarily controls coordination of movements and integration of
sensory feedback.
The cerebral nuclei (choice B), also located deep in the
cerebrum, primarily controls coordination and preparation of limb
movements.
The superior colliculi (choice D), located in the
mesencephalon, processes visual information and the vestibular
nuclei (choice E), located in the pons and medulla oblongata,
processes equilibrium sensations.
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