Fig. 1
From: A patient-specific treatment model for Graves’ hyperthyroidism
The HPT axis. A negative feedback loop of the hypothalamus-pituitary-thyroid (HPT) axis is shown in this picture. The thyroid stimulating hormone (TSH) stimulates the thyroid gland to produce and secrete the hormones, triiodothyrnoine (T3) and thyroxine (T4), which in turn inhibits the production of TSH. A minus sign indicates the negative feedback