They remain but are at the very bottom and don't present any issue. I actually just pour into another cup but you can just drink from the blender cup. I LOVE this- so much more convenient than my big blender and enough power for mixing protein shakes!
The blades are inside the cup, and don't come out. The bottom is weird in that it is not closed off completely.It isn't a flat surface at the bottom like a regular cup. If that makes any sense. Hope this helps!