Major Glial Cell Types
A.k.a. “neuroglia” or “glial cells”, these cells of the nervous system have four main functions:
- surround neurons and hold them in place
- supply nutrients and oxygen to neurons
- electrically insulate neurons from each other
- destroy germs and remove dead neurons
– Macroglia of the Central Nervous System (CNS) –
Astrocytes (or astroglia) are the most abundant macroglia in the CNS. They remove excess potassium ions (K+) from around neurons; link neurons to a blood supply while helping form the blood-brain barrier; recycle neurotransmitters released during synaptic transmission; and signal to each other using glutamate, GABA, and adenosine tri-phosphate (ATP, a molecule used for energy by all living cells).
Ependymal cells (or ependymocytes) line the spinal cord and the ventricular system of the brain to create the ependyma, a part of the blood-CSF barrier. They are involved in creating, secreting, and circulating cerebro-spinal fluid (CSF).
Oligodendrocytes coat the axons of neurons in the CNS with their cell membranes to form myelin sheaths; a single oligodendrocyte can serve up to 50 axons.
– Microglia –
Microglia are much smaller than macroglia and can change shape in order to move around the entire nervous system. They multiply when the brain is damaged, and constantly sample their environment in order to direct immune system responses to damage or danger in the nervous system.
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Vigilante Intergalactic Roustabout Scholars (VIRS) by Danbee Kim is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
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