Neuroglia, or glial cells, have several critical functions:
Astrocytes: Provide structural support, regulate the extracellular ion and neurotransmitter concentrations, and maintain the blood-brain barrier. Oligodendrocytes: Produce the myelin sheath in the CNS, which insulates axons and enhances the speed of electrical impulses. Microglia: Act as the immune cells of the CNS, phagocytosing debris and protecting against pathogens. Ependymal Cells: Line the ventricles of the brain and the central canal of the spinal cord, involved in the production and circulation of cerebrospinal fluid. Schwann Cells: Form the myelin sheath in the PNS and assist in the regeneration of damaged axons. Satellite Cells: Provide support and nutrition to the neurons in the PNS ganglia.
