Can a Catholic donate their body to the local medical school to be a cadaver for the students? If not, can I as a Catholic take classes that require me to use a cadaver?
Yes, Catholics can donate their bodies to science. Just make sure to stipulate to the school that the body is to be properly disposed of after they are done with it. This can either be done by having the body cremated and the ashes properly disposed of or by burying the body.
As for Catholic students, yes, they can work on human cadavers.