In this subchapter:
(1) "Physician" means a person licensed to practice medicine in this state under Subtitle B, Title 3, Occupations Code.
(2) "Relief services" means the temporary coverage of a physician's practice by another physician for a predetermined time during the physician's absence and before the physician's return.
(3) "Rural" means:
(A) a community located in a county with a population not greater than 50,000;
(B) an area designated under state or federal law as:
(i) a health professional shortage area; or
(ii) a medically underserved area; or
(C) a medically underserved community designated by the department.