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).
Schwann cells and oligodendrocytes make the myelin sheaths of the peripheral nervous system (PNS) and central nervous system (CNS), respectively. Their myelin sheaths are structurally similar, consisting of multiple layers of specialized cell membrane that spiral around axons.