When I specifically contacted AMCAS about where to place my nursing courses such as anatomy & physiology and microbiology, this was their response: "Applicants are responsible for determining the classification of each course based on the primary course content. AMCAS reserves the right to change course classifications if the assigned course classification clearly does not apply."
Basically, use your best judgment and then see what they do with it.
MD Candidate, Class of 2017
School of Medicine
Oregon Health & Sciences University