Answer:
Glial cells called 'Glai' or 'neuroglia'
'Oligodendrocytes' create the myelin that envelope axons.
Explanation:
Glial cells are non neuronal cells in the CNS (central nervous system) i.e, the brain and spinal cord, and the peripheral nervous system (nerves and ganglia outside the CNS) that do not produce electrical impulse.
They maintain homeostasis, form myelin sheath, surrounds and hold neurons, supply nutrients and oxygen to neurons, fight and destroy pathogen, remove dead neurons, play an important role in neurotransmission and synaptic connections.
In the CNS, Glial cells include the Oligodendrocytes, astrocytes, ependymal cells and microglia while in the peripheral nervous system, the Glial cells are schwann cells and satellites cells.
Oligodendrocytes main function to the Glial cells is to provide support and insulation to the axons of CNS. This is done by creating the myelin sheath. In the peripheral nervous system, schwann cells produce the myelin sheath that support the axons.
Astrocytes, collectively known as astroglia provides biochemical support for endothelial cells that make up the blood- brain barrier, nutrient to nervous tissues and play vital role in repair and scarring act of the CNS as a result of traumatic injury.
Microglia are neuroglia cells that act as the first and active immune defense in brain and spinal cord. They are vital cells in brain maintenance. They regularly scavenge the CNS for plagues, damages and removal of effected or dead neurons
