<prompt> Percentage of T4 and T3 released from thyroid gland-50 T4; 50 T325 T4; 75 T380 T4; 20 T31000 T4; 0 T3  <response>: Ans. is c i.e., 80 T4; 20 T3 Approximately 80 of secreted hormone is T4 and 20 is T3. 