Hi Luv,
I had one because I was an elective section.
They basically weighed me, took my height and asked me about my medical history.
They then ask you stuff relating to a GA - but only to be prepared!!!! So don't worry about it!!!
They will also probably want to know of any dental work you've had done (false teeth, crowns, caps or veneers) and the might measure between your mouth and throat with their hand so that they can have all the essential medical equipment ready for you just in case!
It's good that they get to ask you all this stuff before you go in. You get enough questions when you arrive!!!!
xxx