Final answer:
The CST receives sensory fibers from spinal nerves through the dorsal root and cranial nerves connected to the brain.
Step-by-step explanation:
The corticospinal tract (CST), also known as the pyramidal tract, not only receives motor input but also other nerve fibers. These include sensory fibers from spinal nerves through the dorsal root, which is attached to the dorsal root ganglion. The cranial nerves, which are connected to the brain, also send sensory input to the CST. The cranial nerves can be strictly sensory, such as the olfactory, optic, and vestibulocochlear nerves, or mixed sensory and motor, such as the trigeminal, facial, glossopharyngeal, and vagus nerves.