Levels of thyroid hormones in serum are tightly regulated by the hypothalamic-pituitary-thyroid axis (Figure 1). Hypothalamic TSH-releasing hormone (TRH) is secreted mainly from the paraventricular ...

Regulation of thyroid hormone (TH) levels is a complex multilevel phenomenon. The paraventricular nucleus (PVN) of the hypothalamus (the region of the brain that controls the involuntary nervous ...

The thyroid, a butterfly-shaped gland at the base of the neck, regulates metabolism, energy levels, digestion, and reproductive health. Thyroid disorders are among the most common endocrine conditions ...

TSH in pars distalis (PD-TSH) is controlled by the hypothalamus -- pituitary gland -- thyroid gland (HPT) axis. The hypothalamus secretes the thyrotropsin-releasing hormone (TRH), which stimulates the ...

The thyroid, an endocrine gland found in the anterior neck, is normally not palpable. It regulates the rate of metabolism, growth, and function of other systems through a negative feedback system ...

The thyroid gland produces two thyroid hormones, triiodothyronine (T3) and thyroxine (T4), and releases them as needed by the body. The hypothalamus and the pituitary gland help control the thyroid ...

What is the mechanism by which thyroid dysfunction affects the menstrual cycle? —JULIA ARNETT, ANP, Newton, Mass. Thyroid dysfunction is associated with a range of menstrual abnormalities, including ...