What crosses between CNS & PNS?

• What crosses between CNS & PNS?

• Axons of neurons (motoneurons; DRG’s)
• Microglia- mesodermal cells migrate into CNS
• Basement membrane,
• Establishes interface between CNS and PNS by forming pia
• Follows blood vessels into the CNS
• BM surrounds perivascular cells, endothelial cells, smooth muscle cells of vessels.

• What doesn’t cross between both?

• Oligodendroglia (CNS)
• Astrocytes (CNS)
• Schwann cells (PNS)