The supporting cells of the nervous system that enable neurons to function correctly. There are four main types of glial cells in humans and other mammals. Astrocytes, microglia and oligodendrocytes occur in the brain and spinal cord. Schwann cells are found only in peripheral nerves (nerves other than those in the brain and spinal cord).
From the Greek for "glue," glial cells are supportive cells associated with neurons. Astrocytes and oligodendrocytes are central nervous system glial cells. In the peripheral nervous system the main glial cells are called Schwann cells.
The word "glial" comes from a Greek word meaning "glue." These supporting cells form a protective coating and nourishment for neurons. They are also essential in providing structural support ("scaffolding") for growing and developing neurons. Glial cells multiply throughout the human lifespan.
Cells that serve as supporting elements to the brain and act as scavengers, removing debris after injury or neuronal death. They are also responsible for maintaining ionic balance and producing the fatty coating in nerve cells.