In the reflex, the lower center is aroused by a sensory nerve, and in the voluntary movement by the pyramidal tract.
They included portions of all the tracts, the pyramidal tract as well.
These are cerebral influences acting by way of the pyramidal tract upon the spinal center for the reflex.
pyramidal tract n.
A massive bundle of fibers that originates from the motor cortex and the postcentral gyrus and emerges on the ventral surface of the medulla oblongata. Most of the fibers cross to the opposite side in the pyramidal decussation and descend the length of the spinal cord to innervate muscles of the extremities.