The worst/grossest thing that I've ever experienced was in anatomy class, we had to use circular saws to cut the top of the skull off and quite a few of the bodies had had brain haemorrages. Blood was spilling out of the exposed brains. It was something out a horror movie.

I never went back to that class, actually.

Most of my grossest moments have come from anatomy class, actually. I missed the one where they cut the heads in half using a massive electric saw (thankfully!)