Our brain is divided into two halves, called the left hemisphere and right hemisphere. The left hemisphere controls the right side of our body, and the right hemisphere controls the left side of our body. This is why when we move our right arm, it is the left side of our brain that is controlling the movement.
When something happens to one side of our body, our brain processes and responds to that information in the opposite side of the brain. For example, if we touch something hot with our left hand, the information will travel up to the right side of the brain, which will then tell our right hand to pull away from the hot object.
This ability of the brain to process and control the opposite side of the body is called contralateral control or contralateral brain function. It helps us to coordinate movements and respond to sensory input from both sides of our body.
So, whenever we do anything with one side of our body, it is the opposite side of our brain that is controlling it. This is how our amazing brains work to help us move, feel and interact with the world around us.