From experience the teachers will treat the students with the same respect the students treat them with. If you're nice to them, they'll return the respect.
Overall, there was a lot more trust from teachers. They treated us like adults, and to an extent as equals. Of course they were still the authoritive figures, but the formality changed; there was a lot more informal discussions, sarcasm, jokes, relaxed environments, and friendliness.
I guess it was the idea that these were the two years that students would 'need' their teachers the most, and they knew it. Therefore there was a more informal relationship established throughout the school. Plus we were no longer generalised as the juniors! n_n
I remember in Ancient last year, we took off a while two weeks of Ancient classes, and my teacher lined her classroom with massive Butchers paper, and we were allowed to paint frescoes! It was brilliant! Not only did we have fun, but it also taught us the techniques and stylistic art forms that went into the frescoes of Santorini. Those two weeks will always be remembered, the informality allowed us to develop closer relations with each other and our teacher. It will be sad to take our frescoes down when we return, in order to allow this years' year 11 the same opportunity.