Another example of a synthesis reaction is the formation of sodium chloride (table salt). Because of the very high reactivities of sodium metal and chlorine gas, this reaction releases a tremendous amount of heat and light energy.
Schwann cells make myelin in the peripheral nervous system (PNS: nerves) and oligodendrocytes in the central nervous system (CNS: brain and spinal cord). In the PNS, one Schwann cell forms a single myelin sheath (Figure 1A).
1 Myelin is made of fat, and it helps to speed transmission of a nerve impulse down a long axon. 2  Myelinated neurons are typically found in the peripheral nerves (sensory and motor neurons), while nonmyelinated neurons are found within the brain and spinal cord.