The board shall control the expenditures of all moneys collected to the credit of the hospital fund, and the construction, leasing, equipping of such hospital and the grounds and other property real and personal belonging to such hospital, providing all moneys from taxes, donations and from any other source shall be deposited in the hospital treasury, and drawn upon by warrants signed by the president and secretary of hospital. The board shall also employ such help, professional and otherwise, as may be necessary to carry out the spirit and intent of sections 205.460 to 205.570, and all such assistants and employees shall serve at the pleasure of the board.