Glial cells
| Type of glial cell | Origin | Appearance | Functions |
|---|---|---|---|
| Astrocytes | Neuroectoderm | Round vesicular nuclei Contain glial fibrils, composed of glial fibrillary acidic protein |
• Repair • Structural & metabolic support • Blood-brain barrier • Remove excess neurotransmitters, related with Hyperammonemia |
| Oligodendrocytes | Neuroectoderm | Small nuclei surrounded by a pale halo Fewer processes than astrocytes |
• Myelinate axons in the CNS, including CN II • Main glial cells in the cerebral white matter |
| Microglia | Primitive yolk sac macrophages | Small elongated nuclei Many short branching processes |
Special macrophages in CNS, i.e. phagocytic |
| Ependymal cells | Neuroepithelial cells (neuroectoderm) | Simple columnar glial cells | Form the epithelium lining the ventricles and central canal of the spinal cord |
Mnemonic
Glial cells guard the axons of the nerve cells as COPS: CNS axons are myelinated by Oligodendrocytes; PNS axons are insulated by Schwann cells.
Oligodendrocytes → multiple sclerosis
Schwann cells → Guillain-Barré syndrome