Glial Cells

Sumit Karia MD

The Common vein Copyright 2010

Definition

Glial cells (aka neuroglial cells) are the second of two basic types of cells in the brain.  The name glia originates from the word glia which in Greek means glue.  Their function is to support the function of the neurons.  The function of neurons is conditioned by glial cells:

There are 3 common types of glial cells;  astrocytes, oligodendrocytes and microglial cells.

The astrocytes are essential for neuron function since they collect the substrates from the blood required for metabolism of neurons and they regulate the composition of the extracellular environment of the nervous system.  they are often found near blood vessels and are resposible for the blood brain barrier.

Oligodendrocytes are responsible for myelination of axons.

The  microglia, corresponds to mononuclear cells (monocyte-macrophage). They are visible only in case of damage to the nervous system to ensure its defense.  They are the smallest of the cells as their name implies.