The central nervous system consists of the brain and spinal cord. Cranial nerves, spinal nerves, and ganglia make up the peripheral nervous system. The afferent division of the peripheral nervous system carries impulses to the CNS; the efferent division carries impulses away from the CNS.
Give them exercises they are good at. Make sure they feel happy if not ask about what to change. And make everyone be happy with your times. (If you have them!)