Piston valves are one form of valve used to control the flow of steam within a steam engine or locomotive. They control the admission of steam into the cylinders and its subsequent exhausting, enabling a locomotive to move under its own power.
Answer: The right side of the brain controls the left side of the body and vice versa So if damage occurs on the right side of the brain that controls the movement of the arm, the left arm may be weak or paralyzed.
