gland, thyroid

gland, thyroid A gland that makes and stores hormones that help regulate heart rate, blood pressure, body temperature, and the conversion of food to energy (metabolism). Thyroid hormones are also essential for proper growth and development. The thyroid gland is located in the lower part of the neck, below the Adam’s apple, wrapped around the windpipe (the trachea). It has the shape of a butterfly: two wings (lobes) attached to one another by a middle part. The thyroid uses iodine, a mineral found in some foods and in iodized salt, to make its hormones. The two most important thyroid hormones are thyroxine (T4) and triiodothyronine (T3). Thyroid stimulating hormone (TSH), which is produced by the pituitary gland, acts to stimulate hormone production by the thyroid gland. The thyroid gland also makes the hormone calcitonin, which is involved in calcium metabolism and stimulating bone cells to add calcium to bone. See also calcitonin; hyperthyroid; hypothyroidism; thyroxine; triiodothyronine.