Final answer:
Oligodendrocytes have a 'fried egg' appearance histologically, which is true, as they possess processes that extend from the cell body and form a myelin sheath around axons in the central nervous system. They are one of the types of glial cells, distinct from Schwann cells which only myelinate axons in the peripheral nervous system.
Step-by-step explanation:
It is true that oligodendrocytes can have a 'fried egg' appearance histologically. Oligodendrocytes are glial cells in the central nervous system that insulate axons with a myelin sheath, which is reminiscent of the white of a fried egg, while the cell nucleus represents the yolk. In contrast to oligodendrocytes, Schwann cells myelinate axons in the peripheral nervous system, and each Schwann cell ensheathes only one axon segment. Oligodendrocytes can myelinate multiple axon segments, either of the same axon or separate axons, which differentiates them from Schwann cells.
The myelin sheath forms an insulating layer, but it is not around the dendrites; rather, it is around the axons. This layer increases the speed at which nerve impulses (action potentials) travel along the axon. The cerebellum is a part of the brain, but it does not make up most of the brain nor is it divided into four lobes. The statement that glial cells produce action potentials is also false, as they support and insulate neurons but do not generate these electrical impulses themselves.