A major difference between Schwann cells and Oligodendroglia is that...
1) Only one oligodendroglia makes myelin for one neuron
2) Oligodendroglia are primarily in the CNS and Schwann cells are in the PNS
3) There are more Schwann cells than oligodendroglia
4) Schwann cells make myelin and Oligodendroglia help remove debris in the CNS