I'm not sure if MND is the 'more common' term for the disease, I've heard it called Lou Gehrigs but never motor neurone disease. That aside, they both don't start with an A so they shouldn't count for this quiz
Seems like ALS is a particular form of MND. Outside the US it seems more common to use the term MND rather than the specific form of the disease, at least outside of the medical profession.
You should accept auricle for atrium though.