The nerve fibers originate in the cerebral cortex and control movement cross the midline just above the junction of the medulla and spinal cord. As a result, these fibers provide input to _________ structures of the body or structures that are on the _________ side of the midline as the cortical cells providing their motor input.
A) ipsilateral; same
B) contralateral; opposite
C) ipsilateral; opposite
D) contralateral; same

Question

Quizplus · Accepted Answer

The question is asking about nerve fibers that control movement and their input to structures in the body. The key phrase is "cross the midline" which means that the fibers are controlling movement on the opposite side of the body from where they originate in the cortex. This is known as contralateral control. Therefore, the answer is B - contralateral; opposite.

The Nerve Fibers Originate in the Cerebral Cortex and Control