What do the statements "#pragma managed(push, off)" and "#pragma managed(pop)" mean?

I am looking at some C++/CLI code and have seen a lot of such statements mostly around #includes. What do they mean? I know that they, according to MSDN, Enable function-level control for compiling functions as managed or unmanaged. But I am interested in their inner mechanics especially the push and pop semantics. If someone could explain how either one of the two statements works, I will figure out the other one myself.