Relationship between the hypothalamus, the anterior pituitary, and it’s target organs is shown, using the thyroid as an example. Hypothalamic thyrotropin-releasing hormone (TRH) stimulates secretion of thyroid- stimulating hormone or thyrotropin(TSH) ,which stimulates synthesis and secretion of thyroid hormone (TH). In addition to their effects on target organs, TH inhibits TSH secretion from the pars distalis and TRH secretion from the hypothalamus by negative feedback.