Joseph is a 59-year-old construction worker who recently suffered a stroke. A small blood clot became lodged in one of the vessels serving the right side of his brain and restricted blood flow to a portion of his right precentral gyrus. Many neurons in that area were damaged or destroyed and, as a result, Joseph is partially paralyzed on the left side of his body. He is able to move his left leg and walk, and can also move his left arm, but his left hand and the left side of his face are paralyzed. Why were Joseph s left face and hand paralyzed, but not the rest of his arm or his leg?