thyroid hormone negative feedback loop
When temperature drops back below the set point, negative feedback is gone, and the furnace comes back on. Feedback loops are used extensively to regulate secretion of hormones in the hypothalamic-pituitary axis. An important example of a negative feedback loop is seen in control of thyroid hormone secretion.The thyroid hormones thyroxine and triiodothyronine (T4 and T3) are synthesized and secreted by thyroid glands and affect metabolism throughout the body. When blood concentrations of thyroid hormones increase above a certain threshold, TRH-secreting neurons in the hypothalamus are inhibited and stop secreting TRH. 2  This is an example of negative feedback.