CNS is made of the brain and spinal cord. There are 3 parts of the brain that are common to all mammals-cerebrum, cerebellum and brain stem.
Cerebrum is the largest part of the brain and is split into 2 central hemispheres which are separated by the deep sagittal fissure.
Cerebellum is a movement control centre with extensive connections with the cerebrum and spinal cord.
Brain stem is where the vital functions are regulated and is considered to be the primitive part of the mammalian brain, damage to this causes death.