- An adjective and a noun, pertaining to the thyroid gland or, less often today, to a preparation made of mammalian thyroid tissue to treat hypothyroidism. For example, the sentence "My thyroid is not making enough thyroid hormone" uses "thyroid" (redundantly) as both an adjective and noun. The thyroid is located in the lower part of the neck below the Adam's apple. It is wrapped around the windpipe (the trachea) and has the shape of a butterfly, since it is formed by two wings (lobes) which are attached by a middle part. Thyroid hormones are essential for the function of every cell in the body. They help regulate growth and the rate of chemical reactions (metabolism) in the body. The thyroid makes and stores these hormones that help regulate heart rate, blood pressure, body temperature, and the rate at which food is converted into energy. Thyroid hormones also help children grow and develop. The thyroid uses iodine, a mineral found in some foods and in iodized salt, to make several of its hormones.
* * *1. Resembling a shield; denoting a gland (t. gland) and a cartilage of the larynx (t. cartilage) having such a shape. 2. The cleaned, dried, and powdered t. gland obtained from one of the domesticated animals used for food and containing 0.17–0.23% of iodine; formerly widely used in the treatment of hypothyroidism, cretinism, and myxedema, in certain cases of obesity, and in skin disorders. [G. thyreoeides, fr. thyreos, an oblong shield, + eidos, form]
* * *thy·roid 'thī-.rȯid also thy·roi·dal thī-'rȯid-əl adj1 a) of, relating to, affecting, or being the thyroid gland <\thyroid disorders>2) of, relating to, or being the thyroid cartilagethyroid n1) a large bilobed endocrine gland of craniate vertebrates that arises as a median ventral outgrowth of the pharynx, lies in the anterior base of the neck or anterior ventral part of the thorax, is often accompanied by lateral accessory glands sometimes more or less fused with the main mass, and produces esp. the hormones thyroxine and triiodothyronine called also thyroid gland2) a preparation of the thyroid gland of various domesticated food animals (as pigs) containing approximately 1/10 percent of iodine combined in thyroxine and used in treating thyroid disorders called also thyroid extract
* * *thy·roid (thiґroid) [Gr. thyreoeidēs, from thyreos oblong shield + eidos form] 1. glandula thyroidea. 2. pertaining to the thyroid gland (glandula thyroidea). 3. scutiform. 4. [USP] a preparation of cleaned, dried, powdered thyroid gland obtained from domesticated food animals and free of connective tissue and fat; it contains levothyroxine and liothyronine and is used as replacement therapy in the diagnosis and treatment of hypothyroidism, to prevent and treat goiter, and to prevent and treat thyroid carcinoma, administered orally.
Medical dictionary. 2011.