Final answer:
Glial cells are non-neuronal cells that support and protect neurons. In the CNS, astrocytes regulate extracellular fluid and oligodendrocytes produce myelin. In the PNS, Schwann cells produce myelin and satellite cells provide support and nourishment to neurons.
Step-by-step explanation:
Glial cells, also known as neuroglial cells, are non-neuronal cells that provide support and protection for neurons in the nervous system. In the central nervous system (CNS), there are two types of glial cells: astrocytes and oligodendrocytes. Astrocytes are star-shaped cells that help regulate the composition of the extracellular fluid, provide nutrients to neurons, and play a role in the formation of the blood-brain barrier. Oligodendrocytes, on the other hand, produce myelin, a fatty substance that wraps around axons and aids in electrical signal transmission.
In the peripheral nervous system (PNS), there are two types of glial cells: Schwann cells and satellite cells. Schwann cells wrap around axons in the PNS, forming the myelin sheath that insulates and speeds up the conduction of electrical impulses. Satellite cells, similar to astrocytes, provide support and nourishment to neurons in sensory and autonomic ganglia.