Chapter 7: the structure of the nervous system. Ns of all mammals has two division: the cns and the pns. Anatomical references: read page 169 and 170. Rostral-most and largest part of the brain. It is split down the middle into two hemispheres; separated by the deep sagittal fissure. The right hemisphere receives information and controls the left side of the body; the left hemisphere receives information and controls the right side of the body: the cerebellum. It contains as many neurons as both cerebral hemispheres combined. It is primarily a movement control center with extensive connections to the cerebrum and spinal cord. Left side of the cerebrum is concerned with the left side of the body and the same applies to the right portion: the brain stem. Forms the stalk from which the cerebral hemispheres and the cerebellum sprout.