The human body performs myriad chemical reactions, and medical science takes advantage of using drugs to create and control certain chemical interactions. That's why pre-medical students need at least one year of chemistry, one year of organic chemistry and one year of biological sciences which include biochemistry. Chemistry and organic chemistry include laboratory sections.
Mathematical understanding and proficiency are important skills for doctors. Medical schools require one year of mathematics. Some also require a year of calculus specifically. Most schools, including Johns Hopkins School of Medicine, consider statistics a form of mathematics and will accept statistics courses as part of meeting their mathematics requirements.
Medicine itself may be largely a scientific discipline, but doctors must be good communicators, both in writing and speech. Medical schools want candidates to have at least one year of English studies. These should involve literature and etymology, not instructional courses such as English composition or English grammar. Schools want students engaged in enrichment and critical thinking at the same time they are writing papers and improving their academic skills.
American academia holds that physicians should have a well-rounded education and understand more than just subjects related to their craft. Thus, medical schools require at least one year of liberal arts coursework including literature, languages, humanities and social sciences. Some schools, including the University of Washington, do not accept remedial or highly instructional language courses such as foreign language composition courses. Instead, language classes need to focus on the entirety of the language, as a general French or Chinese class would.
In addition to life-science related courses, medical schools want a year of physics. Medical students should be versed in some of the most fundamental principles of physical science and the theories surrounding matter.