You have a friend who is trying to explain to you the different cells of the nervous system using an analogy of an airport and flying. They say the neurons are like airplanes that take people where they need to go quickly. The microglia are like airport security, making sure no bad stuff is in the airport. The oligodendrocytes / Schwann cells are like the flight attendants because they make the trip go smoother and make sure everyone gets where they need to go. The astrocytes are like air traffic controllers because they coordinate all of the airplanes. Pick two of the cell types and explain to me why this analogy is missing or how it is not quite perfect..