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).
All CNS (central nervous system, i.e. brain and spinal cord) fibres are myelinated. The only difference between myelination in the CNS and the PNS (peripheral nervous system) is the type of cell responsible for myelination.In the PNS these are Schwann cells. Each of these wraps around and insulates a short length (about 1mm) of a single axon. In the CNS, oligodendrocytes provide myelination.These cells project to and wrap a portion of several axons so they also provide a kind of '3D scaffolding' as well as myelination.n the PNS these are Schwann cells. Each of these wraps around and insulates a short length (about 1mm) of a single axon. In the CNS, oligodendrocytes provide myelination. These cells project to and wrap a portion of several axons so they also provide a kind of '3D scaffolding' as well as myelination.