Question

Where does the oldest upper motor neuron (UMN) pathway originate?

a. Cerebral cortex
b. Brainstem
c. Spinal cord
d. Cerebellum

Answer 1

The oldest upper motor neuron pathway originates in the cerebral cortex.

Step-by-step explanation:

The oldest upper motor neuron (UMN) pathway originates in the cerebral cortex.

The corticospinal tract is responsible for voluntary movements of skeletal muscles and is formed by the axons of large cortical neurons called Betz cells. These axons descend from the primary motor cortex to activate upper motor neurons in the ventral horn of the spinal cord.

Therefore, the correct answer is: a. Cerebral cortex.