Glial Cells

Astrocyte

Structure

• Most numerous

• Star shaped

• Found near neurons

Function

• Help regulate neurotransmitter & ion levels

• Help form blood-brain barrier

• Help with synapse formation

Microglial Cell

Structure

• Smallest; Least abundant

• Many pointed projections like a thorny bush

Function

• Phagocytize dead neurons and microorganisms

Ependymal Cell

Structure

• Ciliated, simple cuboidal cells

• Line the ventricles in the brain and cavities of the CNS

Function

• Help produce the cerebrospinal fluid

• Help circulate the CSF

• Help form the Blood-brain barrier

Oligodendrocyte

Structure

• Have octopus-like shape

• Have processes that wrap around segments of several axons in the CNS

Function

• Protect the neuron cell bodies in ganglia

Satellite Cell

Structure

• Surround the neuron cell bodies in ganglia

Function

• Myelinate certain axons of CNS neurons

• Wraps around other axons of CNS to protect & support them (though not insulate them)

Schwann Cell (Neurolemmocyte)

Structure

• An entire cell wraps around a section of a nerve fiber in the PNS

Function

• Myelinate the axons (nerve fibers) of PNS neurons

• Helps repair injured nerve fibers in the PNS