Glial cell
Say it: GLEE-ul SEL
A glial cell is a non-neuronal cell of the nervous system that supports, insulates, feeds and protects neurons and helps regulate their signaling.
Also: glia, neuroglia, glial cells
Definition
What is a glial cell?
Glial cells, or neuroglia, are the other main cell population of nervous tissue besides neurons. They do not fire action potentials, so for a long time they were treated as mere packing material; the German pathologist Rudolf Virchow named them after the Greek word for glue in 1856. Research now shows they shape how neurons work, and unlike most neurons many of them can still divide in adults.
The central nervous system has four kinds. Astrocytes, star-shaped cells, control the fluid around neurons by removing excess neurotransmitter and potassium, supply them with fuel, and help form the blood–brain barrier. Oligodendrocytes wrap myelin around stretches of several axons, which speeds nerve impulses. Microglia are resident immune cells that engulf debris and microbes and, during development, prune unneeded synapses. Ependymal cells line the brain's ventricles and help produce and circulate cerebrospinal fluid. The peripheral nervous system has two kinds: Schwann cells, each of which myelinates a segment of a single axon, and satellite cells, which surround neuron cell bodies in ganglia.
Glial cells are central to several diseases. Multiple sclerosis strips away myelin made by oligodendrocytes, overactive microglia are studied in Alzheimer's disease, and gliomas, the most common malignant brain tumors in adults, arise from glial cells or their precursors.
Word parts
Where does the term “glial cell” come from?
- glia
- glueGreek glia
- neuro-
- nerveGreek neuron
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Terms that go with it
- NeuronA neuron is a nerve cell, the basic signaling unit of the nervous system, which receives information and passes it on as electrical and chemical signals.
- MyelinMyelin is the fatty, layered sheath that glial cells wrap around many axons, insulating them so nerve impulses travel faster and more efficiently.
- Blood–brain barrierThe blood–brain barrier is the tightly sealed lining of the brain's capillaries that controls which substances can pass from the blood into brain tissue.
- Central nervous systemThe central nervous system is the brain and spinal cord, the part of the nervous system that takes in sensory input, integrates it and sends out commands.
- AxonAn axon is the single long projection of a neuron that carries electrical impulses away from the cell body toward other neurons, muscles or glands.
- MacrophageA macrophage is a large white blood cell that engulfs and digests microbes, dead cells and debris, and signals other immune cells to act.
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Checked against
Written for biofideX in plain words, after checking these references:
- OpenStax Anatomy and Physiology 2e, 12.2 Nervous Tissue
- Queensland Brain Institute: Types of glia
- NCBI MeSH: Neuroglia
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