The phrase hospital district, as used in section 23-3565, shall mean the hospital district as it existed immediately prior to and at the time of the issuance of any bonds by such hospital district, including all lands, property, and inhabitants contained in the hospital district at the time of the issuance of any bonds, and all portions of the district subsequently separated from the district, whether by the formation of a new district or by any change of boundaries of the original district and all territory annexed to the hospital district during the life of such bonds.