About 80% to 90% of pyramidal or corticospinal tracts decussate in the pyramids of the medulla oblongata and descend as the lateral corticospinal tracts. Hence, they are known as “pyramidal tracts.” The uncrossed fibers decussate in the spinal cord, they form the ventral corticospinal tracts.
The movements of trunk receive instructions from the ventral corticospinal tracts, while the lateral corticospinal tracts carry instructions for the movements of arm and fingers.
Thus, the blanks can be filled with trunk; arm; finger.