(a) The commissioners court may make bonds issued under this subchapter payable from and secured by a lien on or pledge of all or part of the hospital district revenue from operation or ownership of hospital facilities, except ad valorem taxes.
(b) The commissioners court may also secure the bonds by:
(1) a pledge of all or part of a grant, a donation, or other income received from a public or private source, whether in accordance with an agreement or otherwise; and
(2) a mortgage or deed of trust on real property on which a district hospital facility is or will be located and any real or personal property incident or appurtenant to that facility.
(c) The commissioners court may authorize the execution and delivery of a trust indenture, mortgage, deed of trust, or other form of encumbrance to evidence a security agreement under Subsection (b)(2).