Footnote
b T3 is triiodothyronine and T4, thyroxine. The digits 3 and 4 refer to the number of iodine atoms attached to the hormone. The thyroid also produces calcitonin, a hormone that helps to regulate calcium levels in the blood.
b T3 is triiodothyronine and T4, thyroxine. The digits 3 and 4 refer to the number of iodine atoms attached to the hormone. The thyroid also produces calcitonin, a hormone that helps to regulate calcium levels in the blood.