Tennessee Code Title 47. Commercial Instruments and Transactions § 47-28-109

(1) Any increase in the principal balance of an indebtedness secured by any mortgage as a result of negative amortization or deferred interest;

(2) Any advance which the creditor is obligated under the terms of the mortgage or related agreement or undertaking to make to a third party, or any disbursement made by a creditor pursuant to the terms of the mortgage to protect the efficacy of the creditor's security, including, without limitation, payment of taxes, insurance premiums, or expenses incurred in making repairs to the property or in the collection of the debt or the enforcement of the mortgage;

(3) Any advance made under a construction or home improvement loan agreement contained or referred to in the mortgage;  and

(4) Interest on such advances or disbursements,

shall be secured by the mortgage, even though the mortgage does not specifically provide for future advances, or the advances or disbursements cause the amount of the total indebtedness to exceed the principal amounts stated in the mortgage, or to exceed the credit limit under an open-end mortgage.  The priority of the lien of the mortgage, including any advance, increase, or disbursement described in this section, shall be the same as if such advance, increase or disbursement was made on the date of the recordation of the mortgage.