Question

what is the placement of white matter and grey matter in brain and spinal cord ?

Answer 1

Think of it this way. The gray matter is where signals start from, and white matter is the path the signals take. So in the cerebral hemispheres, the gray matter is on the outside, and the white matter is on the inside (signals have to travel from the outside, thru the brain to get to the spinal cord). In the spinal cord however, its the other way, the gray matter is on the inside, and the white matter is on the outside (here, the signals start in the inner part and travel outward to rest of the body)