The Board of Regents shall promulgate appropriate rules and regulations pertaining to the admission of students to medical schools which will provide for admission of those students to its entering class each year who are equally or as well qualified as all other students and who have entered a contract with or received a commitment for a stipend, grant, loan or scholarship from the State Rural Medical Education Board. The State Rural Medical Education Board may contract with medical students providing for such students to engage in a general or family practice of medicine for not less than four years after licensing and a period of medical residency, as determined by the rules and regulations established by the State Rural Medical Education Board, in cities of Texas which have a population of less than 5,000 or in rural areas, as that term may be defined by the State Rural Medical Education Board, and said Board is hereby given the authority to define and from time to time redefine the term rural area, at the time the medical practice is commenced. This contract shall provide for a monthly stipend of at least $100 to be granted by the State Rural Medical Education Board to each person under contract with the state while enrolled as a medical school student.