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Glial cell
Make it clearer
When people talk about the brain, they almost always talk about neurons, but the most abundant cells in the central nervous system are not those: they are the glial cells, or glia. They are the crew that maintains the wiring: you never see them, and without them no signal gets through.
There are several types, and the names are worth knowing. Oligodendrocytes and Schwann cells, astrocytes, microglia and ependymal cells. They do not all do the same thing.
The first two make myelin, a wrapping of fatty layers that sheathes the axon, that is, the long extension a neuron uses to send its signal. Just like the plastic on a wire, that wrapping insulates, and thanks to it the impulse travels much faster. Astrocytes, which are star shaped, rest their end feet on blood vessels and form part of the blood-brain barrier, the filter that decides what in the blood is allowed into the brain. And then there are microglia and ependymal cells, the other two members of that same support crew.
In brief
Glial cells are the most abundant cells in the central nervous system: they support neurons, help maintain homeostasis and form myelin.
The crew that maintains the wiring: you never see them, and without them no signal gets through.
The most notable ones are oligodendrocytes, Schwann cells, astrocytes, microglia and ependymal cells.
The myelin they make insulates the axon and speeds up the impulse, and astrocyte end feet are part of the blood-brain barrier.
Sources (1)
- National Center for Biotechnology Information, StatPearls PublishingHistology, Glial Cells, StatPearlsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
Updated