when you show actors face in movie it's a close up, when you show his eye (just one) it's macro. but when you go for macro photography definition to wikipedia (for example) they mix those words together so you could use them both for same meaning. i don't like using close up for what i do. it's macro photography - all about very small objects in their full details.
some examples
close up
macro
but i still call the first one macro. don't ask me why. maybe it's because this flower is still very small.
another example
close up 2
http://www.klysewicz.co.uk/images/ph...aynox_3760.jpg
macro 2
again i'll say both are macro - background is not important. i would say that first one could be treated as close up but with more details around. like here
close up 3 - proper one in my opinion
but i'm not a specialist 
i'm wondering what others will say.