Explanation

All are correct I,III and IV. Neuroglial cells are the packing and supporting cells found in brain and spinal cord. They are of three types, i.e., astrocytes, oligodendrocytes and microglia Astrocytes are responsible for separation of two neurons by insulation. Oligodendrocytes are a category of glial cells that form myelin sheath around the axon Microglia are phagocytic as well as scavengers. They engulf microbes and cellular debris. Nearly 50% of all brain cells are neuroglia Schwann cells are the neuroglial cell, which are present in PNS