The corporation shall have a board of directors, which shall constitute the governing body of the corporation. The members of the board of directors shall be residents of the county and shall be elected by the county commission of the county for staggered terms of office as follows:

(1) The first term of one third of the directors shall be for two years;

(2) Of another one third for four years;

(3) The remaining one third for six years; and

(4) Thereafter the term of office of each director shall be six years; provided, that if any resolution adopted, pursuant to the provisions of Section 22-21-72, by the county commission of a county having a population of more than 300,000 and less than 500,000, according to the last or any subsequent federal census, shall contain requirements respecting the election of the directors of the corporation authorized in the said resolution, then the directors shall be elected in the manner and for the terms and by the governing bodies that may be specified in the said resolution.

If any director dies, or resigns, or becomes incapable of acting as a director or ceases to reside in the county, the county commission that elected him may elect a successor to serve for the unexpired period of his term. Directors may succeed themselves in office, if again elected by the applicable county commission. The members of the board of directors shall serve without compensation, except that they may be reimbursed for actual expenses incurred in the performance of their duties as directors. No member of the board of directors shall be an officer of the county or of any incorporated municipality in the county; provided, that if any resolution, adopted pursuant to the provisions of the said Section 22-21-72, by the county commission of a county having a population of more than 300,000 and less than 500,000, according to the last or any subsequent federal census, shall so provide, then any director of the corporation authorized in the said resolution may be a member of the governing body, whether of the county or of a municipality therein, that elects him as director until such time as a special annual ad valorem county tax for public hospital purposes shall be voted in any such county.