Neuroscience for Kids

Glia:The Forgotten Brain Cell

The brain is made up of more than justnervecells (neurons). While thereare about 100 billion neurons in the brain, there are about 10 to 50 timesthat many GLIAL CELLS in the brain. But doyou hear much about glia? NO! Since neurons get allthe attention, you don't hear too much about glia. While glia cells DONOT carry nerve impulses (action potentials) they do havemany important functions...in fact, without glia, the neurons would notwork properly!

Types and Functionsof Glia
Name of Glial Cell Function
Astrocyte
(Astroglia) Star-shaped cells that provide physical and nutritional support forneurons: 1) clean up brain "debris"; 2) transport nutrients to neurons; 3)hold neurons in place; 4) digest parts of dead neurons; 5) regulatecontent of extracellular space
Microglia Like astrocytes, microglia digest parts of dead neurons.
Oligodendroglia Provide the insulation (myelin) to neurons in thecentral nervous system.
Satellite Cells Physical support to neurons in the peripheral nervous system.
Schwann Cells Provide the insulation (myelin) to neurons in the peripheral nervous system.

Types and Functionsof Glia
Name of Glial Cell	Function
Astrocyte (Astroglia)	Star-shaped cells that provide physical and nutritional support forneurons: 1) clean up brain "debris"; 2) transport nutrients to neurons; 3)hold neurons in place; 4) digest parts of dead neurons; 5) regulatecontent of extracellular space
Microglia	Like astrocytes, microglia digest parts of dead neurons.
Oligodendroglia	Provide the insulation (myelin) to neurons in thecentral nervous system.
Satellite Cells	Physical support to neurons in the peripheral nervous system.
Schwann Cells	Provide the insulation (myelin) to neurons in the peripheral nervous system.

There are a few ways in whichglia cells are different from neurons:
Neurons have TWO "processes" called axons and dendrites....glial cellsonly have ONE.
Neurons CAN generate action potentials...glial cells CANNOT. However,glial cells do have a resting potential.
Neurons HAVE synapses that use neurotransmitters...glial cells do NOThave chemical synapses.
Neurons do NOT continue to divide...glial cells DO continue to divide.
There are many MORE (10-50 times more) glial cells in the braincompared to the number of neurons.

HearIT!	"Astrocyte"	"Glia"	"Microglia"
HearIT!	"Neuron"	"Oligodendroglia"	"Schwann cells"

More on glia:

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Exploring theNervous System