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 Oligodendrocytes-neuroglial cells of ectodermal origin that myelinate axons in the central nervous system and forms the white matter of the central nervous system (unmyelinated axons are grey matter. 2  Astrocytes-star-shaped nutritive and supportive glia cells of the central nervous system.