Tennessee Code Title 47. Commercial Instruments and Transactions § 47-28-102

A mortgage may provide that it secures not only existing indebtednesses or advances made contemporaneously with the execution thereof, but also future advances, whether obligatory, or optional, or both, and whether made under open-end credit agreements or otherwise, to the same extent as if such future advances were made contemporaneously with the execution of the mortgage, even though no advance is made at the time of the execution of the mortgage and even though no indebtedness is outstanding at the time any advance is made.