The board shall not borrow money on its general faith and credit, nor create any liens upon its property. With the approval of the legislature the board may borrow money to be used to acquire land or to acquire or erect buildings, or to alter, equip, or maintain them, to be used as dormitories, student centers, stadiums, athletic fields, gymnasiums, auditoriums, and other related activities, and it shall obligate itself for the repayment of the money, together with interest, solely out of the fund derived from rentals or other income from the use and operation of the property so acquired, or from special fees and charges required to be paid by the students if the board considers the students to be benefited; and may pledge all or a part of the fund as security for the loan.